A Typical Material Selection Report

CONTENTS 1.

INTRO INTRODUC DUCTIO TION.. N...... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ........ ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... .......... ..........1 ....1 1.1

Objective Objective of Documen Document....... t.............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .................. ......................... .............. 1

1.2

Scope.... Scope........... .............. ............... ............... .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .................. ......................... .............. 1

1.3

Abbrevia Abbreviation tions...... s............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. ............. ...... 2

1.

Units of !easure !easurement ment....... .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .................................3 ..........................3

1."

Co#es Co#es an# Stan#ar# Stan#ar#s..... s............ .............. .............. .............. .............. .............. .............. ............... ............... .............. .............. .............. .............. .............. ....... 

2.

SU!!AR SU!!AR$.. $...... ....... ....... ....... ....... ........ ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ........ .......... ........... ........." ...."

3.

D%SI&N D%SI&N DAT DATA....... ........... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ........ ....... ....... ....... ......... ...........11 .....11 3.1

Sources Sources of Data. Data........ .............. .............. .............. .............. .............. .............. .............. .............. ............... ............... .............. .............. ....................... .................. .. 11

3.2

Desi'n Desi'n (ife......... (ife................ .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. ...................11 ............11

3.3

)*ui# )*ui# Compositi Compositions.. ons......... .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. ........................... .................... 11 3.3.1

Oi* Compositi Composition... on.......... .............. .............. .............. .............. .............. .............. .............. ............... ............... .............. .............. ..................11 ...........11

3.3.2

&as (ift (ift Compositi Composition... on........... ............... .............. .............. .............. .............. .............. .............. .............. .............. .............. .................11 ..........11

3.3.3

+ro#uce# +ro#uce# ,ater ,ater Ana*-s Ana*-sis...... is............. .............. .............. .............. .............. .............. .............. .............. .............. ......................12 ...............12

3.

+ressures +ressures an# Temperatur mperatures.... es........... .............. .............. .............. .............. .............. .............. .............. .....................................13 ..............................13

3."

Avai*ab Avai*abi*it-. i*it-........ .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. ................... .................................. ...................... 1

3.

Corrosion Corrosion !o#e* !o#e* Cases..... Cases............ .............. .............. ............... ............... .............. .............. .............. .............. .............. .............. .......................1 ................1

.

3..1

&as (ift /30 +ipe*ine +ipe*ine....... .............. .............. .............. .............. .............. .............. .............. .............. .............. ............................1 .....................1

3..2

&as (ift /0 +ipe*ine +ipe*ine....... .............. .............. .............. .............. .............. .............. .............. .............. .............. ............................1 .....................1

3..3

&as (ift (ift ea#er ea#er an# an# )*o*i )*o*ines... nes.......... .............. .............. .............. .............. .............. .............. .............. .............. .................14 ..........14

3..

+ro#ucti +ro#uction on )*o*ine )*o*ines s / off an# Te Test ea#ers.... ea#ers........... .............. .............. .............. .............. .............. .............15 ......15

3.."

+ro#ucti +ro#uction on ea#ers. ea#ers........ .............. .............. .............. .............. .............. .............. .............. .............. .............. ............................21 .....................21

3..

%6port %6port +ipe*in +ipe*ines es /Seam* /Seam*ess ess (inep (inepipe7 ipe7 &ra#e &ra#e 1" 1" !+a..... !+a............ .............. .........................23 ..................23

3..8

%6port %6port +ipe*in +ipe*ines es /)I /)I (inepip (inepipe7 e7 &ra#e &ra#e 1"! 1"!+a.... +a........... .............. .............. .............. .......................2" ................2"

3..4

+ro#uce# +ro#uce# ,ater ,ater %ffect %ffect !o#e** !o#e**in'.. in'......... .............. .............. .............. .............. .............. .............. .............. .............. ..............2 .......2

!%TO !%TODO DO(O (O&$. &$.... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ........ ....... ....... ....... ....... ......... .......... ........... .........24 ...24 .1

+otentia +otentia** for Corro Corrosion. sion........ .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. ................ ......... 24 .1.1

Corrosion Corrosion !ec9anis !ec9anisms ms an# Consi#e Consi#eratio rations.... ns............ ............... .............. ....................... .............................24 .............24

.1.2

CO2 Corrosion.....................................................................................................24

.1.3

Top of (ine Corrosion. Corrosion........ .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. ...................25 ............25

.1.

Su*p9i#e Su*p9i#e Stress Stress Corrosi Corrosion on Crac:in'... Crac:in'.......... .............. .............. .............. .............. .............. ................. ......................25 ............25

.1."

-#ro'en -#ro'en In#uce# In#uce# Stress Crac:in'. Crac:in'........ .............. .............. .............. .............. .............. ................................3; .........................3;

.1.

-#ro'en -#ro'en %mbritt*e %mbritt*emen ment....... t.............. .............. .............. .............. .............. .............. .............. .............. .............................3; ......................3;

.1.8

C9*ori#e C9*ori#e Stress Stress Corros Corrosion ion Crac:i Crac:in'.... n'........... .............. .............. .............. .............. .............. .............. .............. ...............31 ........31

.1.4

%rosion... %rosion.......... .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. ............... ............... .......... ...32 32

.1.5

Subsea Subsea %6ter %6terna* na* Corrosion Corrosion....... .............. .............. .............. .............. .............. .............. .............. .............. .........................32 ..................32

.1.1; .1.1; Topsi#e psi#e Atmosp Atmosp9eric 9eric Corrosion. Corrosion........ .............. .............. .............. .............. .............. .............. ...............................32 ........................32 .1.11 .1.11 Corrosion Corrosion of t9e (ine +ipe Durin' Durin' Transp Transporta ortation.. tion......... .............. .............. .............. ........................33 .................33 .1.12 .1.12 !icrobia* !icrobia***- In#uce# In#uce# Corrosion. Corrosion........ .............. .............. .............. .............. .............. .............. .............. .............. .............. .............33 ......33 .1.13 .1.13 Un#er Un#er Deposit Deposit Corrosion Corrosion....... .............. ............... ............... .............. .............. .............. .............. ..................................3 ...........................3 .1.1 .1.1 &a*vanic &a*vanic Corrosion Corrosion....... .............. .............. .............. .............. .............. .............. .............. .............. .............. ..............................3 .......................3 .1.1" .1.1" Corrosion Corrosion in Dea# (e's an# Sta'nant Sta'nant
.3

".

Se*ection Se*ection of a Corrosion Corrosion !o#e*.... !o#e*........... .............. .............. .............. .............. ............... ............... ...................... .................................3" ..................3" .2.1

&enera* &enera*....... .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .................... ............. 3"

.2.2

(imitatio (imitations ns of t9e Corrosion Corrosion !o#e*.... !o#e*........... .............. .............. .............. .............. .....................................38 ..............................38

.2.3

+re#ictio +re#iction n of To Top of (ine (ine Corrosion. Corrosion........ .............. .............. .............. .............. .............. .............. .............. ...................38 ............38

!ec9anic !ec9anica* a* !ateria !ateria** Se*ectio Se*ection...... n............. .............. .............. .............. .............. .............. .............. .............. .............. .............. ....................34 .............34 .3.1

=ritt*e =ritt*e )actu )acture re an# %mbritt*e %mbritt*emen ment....... t.............. .............. .............. .............. .............. ....................................34 .............................34

.3.2

)ati'ue )ati'ue....... .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. ............... ............... ............. ...... 35

CORR CORROS OSI> I>IT IT$ $ ASS ASS%S %SS! S!%N %NT T AND AND COR CORRO ROSI SION ON !IT !ITI& I&A ATION.. ION.... .... ..... ..... .... ..... ..... .... ..... ..... .... ..... ...... ....; .; ".1

Corrosivi Corrosivitt- Assessm Assessment ent Resu*ts..... Resu*ts............ .............. .............. .............. .............. .............. .............. .............. ................................; .........................;

".2

Corrosion Corrosion In9ibitio In9ibition n +9i*os +9i*osop9-. op9-........ .............. .............. .............. .............. .............. .............. .............. .............. .............. .......................3 ................3

.

".2.1

&enera* &enera*....... .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .................... ............. 3

".2.2

C9emica* C9emica* +erforman +erformance.... ce........... .............. .............. .............. .............. .............. .............. .............. .................................." ..........................."

".2.3

C9emica* C9emica* Injection Injection S-stem S-stem Desi'n..... Desi'n............ .............. .............. .............. .............. ...................................." ............................."

".2.

Operatio Operation n an# Re*iabi* Re*iabi*it-.... it-........... .............. .............. .............. .............. .............. .............. .............. .............. .............. ..................4 ...........4

+I&& +I&&IN IN& & R%?U R%?UIR IR%! %!%N %NTS TS... ..... .... ..... ..... .... ..... ..... .... ..... ..... .... ..... ..... ..... ..... .... ..... ..... .... ..... ..... .... ..... ..... .... ..... ..... .... ..... ...... ...... ...... ...... ...... ...... .....5 ..5 .1

Operatio Operationa* na* +i'' +i''in'. in'........ .............. .............. .............. .............. .............. .............. .............. ............... ............... .............. .............. ............... ................... ........... 5

.2

Inte**i'e Inte**i'ent nt Inspectio Inspection n +i''in'... +i''in'.......... .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .................."; ...........";

8.

.2.1

&enera* &enera*....... .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .................... ............. ";

.2.2

Inte**i' Inte**i'ent ent +i''in' +i''in' Re@uirem Re@uirements ents....... .............. .............. ............... ............... .............. .............. ............................."; ......................";

.2.3

+i''in' +i''in' )re@u )re@uencenc-....... .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. ...................... ................. .. ";

S+%CI) S+%CI)IC IC !AT !AT%RIA( %RIA( A++(I A++(ICA CATI TION ONS... S...... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ........ ........... ........"2 .."2 8.1

Use of Corros Corrosion ion Resistant Resistant A**o-s... A**o-s.......... .............. .............. .............. .............. .............. .............. .............. ..............................."2 ........................"2 8.1.1

&ra#e &ra#e 3;3; 3;3;( ( Austeni Austenitic tic Stain* Stain*ess ess Stee*s.. Stee*s......... .............. .............. .............. ................................"2 ........................."2

8.2

8.1.2

&ra#e &ra#e 3131 3131( ( Austeni Austenitic tic Stain* Stain*ess ess Stee*s.. Stee*s......... .............. .............. .............. ................................"2 ........................."2

8.1.3

!o SuperBAu SuperBAusten stenitic itic 2" S!O /UNS S312". S312"........ .............. .............. ............... ..........................." ..................."

8.1.

Dup*e6 Dup*e6 Stain Stain*ess *ess Stee*..... Stee*............ .............. .............. .............. ............... ............... .............. .............. .............. .............. ..................." ............"

8.1."

Se*ectio Se*ection n of CRA CRA for +ipe +ipe an# an# >ess >esse*s.... e*s........... .............. .............. .............. .............. .............. ........................" ................."

Use of &*ass &*ass Reinforce Reinforce# # +*asti +*astic c /&R+... /&R+.......... ............... ............... .............. .............. .............. .............. .............. ......................" ..............." 8.2.1

+ipin' +ipin' S-stems... S-stems.......... .............. .............. .............. .............. ............... ............... .............. .............. .............. .............. ........................." .................."

8.2.2

&R+ Tan:s an# an# >ess >esse*s. e*s........ .............. .............. .............. .............. ............... ............... .............. .................................."8 ..........................."8

8.3

Se*ection Se*ection of %*asto %*astomeri meric c Sea*s... Sea*s.......... .............. .............. .............. .............. .............. .............. .............. .............. ..................... ...................... ........1 1

8.

=o*tin' =o*tin' !ater !ateria*s. ia*s........ .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. ..................... .................. .... 1

4.

!AT !AT%RIA %RIA(S (S S%(%C S%(%CTI TION ON AND AND  +(AT +(AT)O )OR! R!... ..... .... ..... ..... .... ..... ..... ..... ..... .... ..... ..... .... ..... ..... .... ..... ..... .... ..... ..... .... ..... .....3 ..3 4.1

,e**9ea ,e**9ea# # %@uipme %@uipment nt /Inc*u#in /Inc*u#in' ' C9o:es C9o:es an# )*o* )*o*ine ine Iso*ati Iso*ation on >a* >a*ves.... ves........... ......................3 ...............3

4.2

+rocess +rocess %@uipme %@uipment.... nt........... .............. .............. .............. .............. ............... ............... .............. .............. .............. ............... .............................. ...................... 3

4.3

5.

4.2.1

&enera* &enera*....... .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .................... ............. 3

4.2.2

&as (ift )irst >a*ve >a*ve On On /)>O7 /)>O7 &as (ift ea#er ea#er an# an# )*o*i )*o*ines........................... nes...........................

4.2.3

+ro#ucti +ro#uction on )*o*ine )*o*ines...... s............. .............. .............. ............... ............... .............. .............. .............. .............. .............. .............. .............. .......

4.2.

Test ea#er..... ea#er............ .............. .............. .............. .............. .............. .............. .............. .............. .............. ....................................8 .............................8

4.2."

+ro#ucti +ro#uction on ea#er ea#er77 +i' (aun (aunc9er c9er an# an# (ast (ast >a* >a*ve ve Off....... Off.............. .............. ......................... ....................5 ..5

Uti*itUti*it- %@uipme %@uipment.... nt........... .............. .............. ............... ............... .............. .............. .............. .............. .............. ................ .................................. ......................... 81 4.3.1

)ue* &as S-stems.... S-stems............ ............... .............. .............. .............. .............. .............. .............. ................. .................................81 .......................81

4.3.2

Open Open Drains....... Drains.............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............82 ......82

4.3.3

>ent >ent an# C*ose C*ose# # Drains Drains an# >en >entt Scrubber... Scrubber.......... .............. .............. .............. .............. .............. .............. ...........83 ....83

4.3.

C9emica* C9emica* Inject Injection ion +ac:a'e +ac:a'e....... .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. ..........8 ...8

4.3."

CC>T +oer +oer &enerati &eneration... on.......... .............. .............. .............. .............. .............. .............. .............. ........................... ......................... .....8 8

4.3.

-#rau*ic -#rau*ic +ipin' +ipin' S-stems... S-stems.......... .............. .............. .............. .............. .............. .............. .............. ........................... ........................ ....8 8

4.3.8

Instrume Instrumentati ntation... on.......... .............. .............. .............. .............. ............... ............... .............. .............. .............. .............. .........................8 ..................8

4.3.4

,as9 ,as9 Don Don ,ater ,ater S-stem..... S-stem............ .............. .............. .............. ............... ............... .............. ............................... .......................... ..88 88

!AT !AT%RIA %RIA( ( S%(% S%(%CT CTIO ION N B +I+% +I+%(I (IN% N%S. S... ..... ..... .... ..... ..... .... ..... ..... .... ..... ..... .... ..... ..... .... ..... ..... .... ..... ..... .... ..... ..... .... ..... ...... ...... ...... ...... .....84 ..84 5.1

!ateria*s !ateria*s an# Corrosion Corrosion A**oan A**oance.... ce........... .............. ............... ............... .............. .............. .............. ................................ ........................... ..84 84 5.1.1

(inepipe (inepipe !anu !anufactu facturin' rin' +roce +rocesses.. sses......... .............. .............. .............. .............. .............. .............. .............. ..................84 ...........84

5.1.2

+ipe*ine +ipe*ines s E Risers Risers B %6port...... %6port............. .............. .............. .............. .............. .............. .............. .............. ..........................85 ...................85

5.1.3

+ipe*ine +ipe*ines s E Risers Risers  &as (ift......... (ift................ .............. .............. .............. .............. ............... ..................................4; ..........................4;

5.1.

+ipe*ine +ipe*ine )ittin's.. )ittin's......... .............. .............. .............. .............. .............. .............. .............. .............. .............. .................................41 ..........................41

5.1."

C9emica* C9emica* Injection Injection *ine /)*atB+ac /)*atB+ac:..... :............ .............. .............. .............. .............. ....................................41 .............................41

5.1. 5.2

5.3

1;.

C*ampin' an# Strappin' materia*s......................................................................41

Coatin' S-stems............................................................................................................. 42 5.2.1

+ipe*ine AntiBCorrosion Coatin' S-stem.............................................................42

5.2.2

Riser Coatin' S-stems.......................................................................................42

Cat9o#ic +rotection......................................................................................................... 43 5.3.1

Sacrificia* Ano#e S-stem....................................................................................43

5.3.2

Corrosion +rotection S-stem Iso*ation  !IFs....................................................43

ASS%T INT%&RIT$ !ANA&%!%NT..............................................................................4" 1;.1

&enera* +9i*osop9-..................................................................................................... 4"

1;.2

Recommen#e# Routine !aintenance Activities..........................................................4"

1;.3

+ossib*e Unp*anne# Activities.....................................................................................4

11.

CORROSION !ONITORIN&..........................................................................................48 11.1

Aim.............................................................................................................................. 48

11.2

!onitorin' an# Testin' )aci*ities.................................................................................48

11.3

!onitorin' !et9o#s.................................................................................................... 44

11.

Corrosion !onitorin' Tec9ni@ues an# %@uipment.......................................................45 11..1 %*ectrica* Resistance /%R +robes......................................................................45 11..2 Coupons............................................................................................................. 45 11..3 =acteria* !onitorin' an# =ioprobes....................................................................5;

11."

+rocess Stream !onitorin'.........................................................................................51

11.

Corrosion !onitorin' Instrumentation.........................................................................51

12.

CORROSION DATA !ANA&%!%NT AND ASS%SS!%NT............................................52 12.1

&enera* Re@uirements................................................................................................ 52

12.2

Data Co**ection )re@uenc-..........................................................................................52

12.3

Data Stora'e...............................................................................................................52

12.

Data Assessment........................................................................................................52

12."

Corrosion Reportin'....................................................................................................52

13.

1.

CORROSION +%R)OR!ANC% TRACGIN&..................................................................5 13.1

&enera* Re@uirements................................................................................................ 5

13.2

Ge- +erformance In#icators........................................................................................5

13.3

Corrective an# +reventative Action.............................................................................5" R%)%R%NC%S................................................................................................................5

A++%NDI 1  T%!+%RATUR% AND +R%SSUR% +RO)I(%S /2 +A&%S A++%NDI 2 CORROSION !OD%( R%SU(TS /2  A3 +A&%S A++%NDI 3 (IST O) UNINI=IT%D %>%NTS /2 +A&%S A++%NDI  C%!ICA( DATAS%%TS /" +A&%S A++%NDI " (A=ORATOR$ T%ST O) ), S%A! CORROSION SUSC%+TI=I(IT$ /1 +A&%

1.

INTRODUCTION

1.1

Objective of Document

1.2

Scope

T9e scope of t9is #ocument is to se*ect suitab*e materia*s for t9e construction of p*atform topsi#e e@uipment7 riser7 pro#uction an# t9e 'as *ift pipe*ines an# risersH an#7 c9emica* injection tubin' /)*at +ac: base# on t9e avai*ab*e f*ui# an# process #ata. Scope of t9e subsea component of t9is stu#- a*so inc*u#es t9e revie an# recommen#ation of • Anticorrosion coatin' for t9e riser an# pipe*ine submer'e# JoneH •

Riser sp*as9JoneH

•

Riser atmosp9eric JoneH

• Ano#e materia* se*ectionH •

+ipin' f*an'es an# fittin'sH

•

C*ampin' an# strappin' materia*s.

Scope of t9e p*atform topsi#e component of t9is stu#- a*so inc*u#es t9e revie an# recommen#ation of •

Se*ection of materia*s for process e@uipment an# pipin'H

•

Se*ection of materia*s for uti*it- an# anci**ar- topsi#e e@uipmentH

•

Specification of corrosion a**oances to be app*ie# across a** e@uipmentH

•

Specification of materia*s for bo*tin' an# po*-meric sea*s.

T9is #ocument recommen#s a Corrosion !ana'ement +*an to mana'e t9e corrosion of t9e assets it9in t9e boun#s #escribe# in t9is #ocument.

1.3

Ab breviat ions

T9e fo**oin' abbreviations 9ave been use# in t9is #ocument

CA

Corrosion a**oance

CO2

Carbon #io6i#e.

C+

Cat9o#ic protection.

CR

Corrosion rate

CSCC

C9*ori#e Stress Corrosion Crac:in'

%N

%*ectroc9emica* noise

%R

%*ectroBresistance

2S

-#ro'en su*p9i#e.

+a'e 1

A<

eat Affecte#
D+%

i'9 Densit- +o*-et9-*ene

%

-#ro'en embritt*ement.

ISC

-#ro'en In#uce# Stress Crac:in'

ID

Insi#e #iameter.

I+

Inte**i'ent pi'

G+

Gi*ometre point.

(+R

(inear po*ar resistance

NORSOG

Nore'ian Tec9nica* Stan#ar#s for +etro*eum Operations

OD

Outsi#e #iameter.

pCO2

+artia* pressure of CO 2.

p2S

+artia* pressure of 2S.

ppm

parts per mi**ion

+>D)

+o*-vin-*#ene )*uori#e

RO>

Remote*- operate# ve9ic*e

SCN)

Strain concentration factor

SSCC

Su*p9i#e Stress Corrosion Crac:in'

TO(C

Top of *ine corrosion.

TSA

T9erma* Spra-e# A*uminium

UDC

Un#er Deposit Corrosion

,T

,a** t9ic:ness.

1.

Units of !easurement

T9e fo**oin' units of measurement 9ave been use# in t9is #ocument

°C

temperature7 #e'rees Ce*sius.

bar

s-stem pressure7 bar.

'*

so*i#s concentration7 'rams per *itre.

'm2s

con#ensation rate7 'rams per s@ meter per secon#.

>

9ar#ness7 >ic:ers.

:m

*inear measure7 :i*ometres.

:+a'

'au'e pressure7 :i*o+asca*s.

m3

vo*ume7 cubic metres.

m'*

so*i#s concentration7 mi**i'rams*itre.

+a'e 2

mm

*inear measure7 mi**imetres.

mm-ear

corrosion rate7 mi**imetres per -ear.

!!scf#

'as f*orate7 mi**ion mi**ion stan#ar# cubic feet per #a-.

!+a

pressure or stress7 me'a+asca*s.

!Sm3#a-

'as f*orate7 mi**ion stan#ar# cubic metres per #a-.

+a

f*ui# a** s9ear7 +asca*.

Sm3#a-

*i@ui#s f*orate7 stan#ar# cubic metres per #a-.

1."

Co#es an# Stan#ar#s

T9e fo**oin' Co#es an# Stan#ar#s 9ave been use# in t9is #ocument

A+I "(

Specification for (inepipe

A+I A

Specification for ,e**9ea# an# C9ristmas Tree %@uipment

AST! A153

Stan#ar# Specification for A**o-BStee* an# Stain*ess Stee* =o*tin' !ateria*s for i'9 Temperature or i'9 +ressure Service an# Ot9er Specia* +urpose App*ications

AST! A15

Stan#ar# Specification for Carbon an# A**o- Stee* Nuts for =o*ts for i'9 +ressure or i'9 Temperature Service7 or =ot9

AST! A32;

Stan#ar# Specification for A**o-BStee* an# Stain*ess Stee* =o*tin' !ateria*s for (oBTemperature Service

AST! A5

Stan#ar# Specification for Carbon an# A**o- Stee* )or'in's for +ipe )*an'es7 )ittin's7 >a*ves7 an# +arts for i'9B+ressure Transmission Service

AST! &

Con#uctin' Corrosion Coupon Tests in +*ant %@uipment

AST! &31

(aborator- Immersion Corrosion Testin' of !eta*s

AST! &

+ractice for %6amination an# %va*uation of +ittin' Corrosion

AST! &41

+ractice for +reparation of !eta**ur'ica* Specimens

DN> OSB)1;1

Offs9ore Stan#ar# B Submarine +ipe*ine S-stems 2;;;

NAC% !RB;18" /no a*so ISO 1"1"

Su*fi#e Stress Crac:in' Resistant !eta**ic !ateria*s for Oi*fie*# %@uipment

NAC% R+ ;88"

+reparation an# Insta**ation of Corrosion Coupons an# Interpretation of Test Data in Oi*fie*# Operations

+a'e 3

2.

SU!! AR$

A summar- of t9e materia*s se*ecte#7 as part of t9is stu#-7 is inc*u#e# in Tab*e 2 B1. Tab%e 2&1

Summar' of materia%s (( p%atforms an# pipe%ines se%ecte# as part of t)is stu#'.

*+uipment Name

Recommen#e# !ateria%

,e**9ea#s

A+I A !ateria* C*ass ))B13.4:+a Stain*ess Stee* /

A%ternatives

A+I A !ateria* C*ass ))B1.":+a Stain*ess Stee* / C9o:e >a*ves

A+I A !ateria* C*ass ))B13.4:+a Stain*ess Stee* / A+I A !ateria* C*ass ))B1.":+a Stain*ess Stee* /

&as (ift +ipe*ine

DN> OS )1;1 &ra#e "; IS+D /coi*e# *ine pipe K 3mm C.A.

&as (ift Riser

DN> OS )1;1 S!( &ra#e 1" ISD K 3mm C.A. %6terna* sp*as9 Jone protection usin' po*-c9*oroprene rubber 12mm t9ic:.

&as (ift )irst >a*ve On

Carbon Stee* =o#- it9 31( trim

&as (ift +i' Receiver

Carbon Stee* K 3.;mm C.A /Sour

&as (ift ea#er


&as (ift )*o*ines


+ro#uction )*o*ines

22Cr Dup*e6 Stain*ess Stee*. %6terna* coatin' to be 14;Lm t9ic: T9erma**Spra-e# A*uminium an# sea*e# it9 an A*:-# Si*icone.

DN> OS )1;1 S!( &ra#e 1" ISD K 3mm C.A.

1 Carbon Stee* K /8mm 7 mm  C.A /Sour e6terna**- coate# it9 14;Lm T9erma**- Spra-e# A*uminium an# sea*e# usin' an A*:-# Si*icone topcoat. 2 Carbon Stee* K 3mm C.A /Sour e6terna**- coate# it9 14;Lm T9erma**- Spra-e# A*uminium an# sea*e# usin' an A*:-# Si*icone top coat. B

)*o*ine Iso*ation >a*ves

So*i# 22 Cr Dup*e6 va*ve bo#-

Carbon stee* bo#- it9 Incone* 2" over*a- for ette# parts.

+ro#uction ea#er

Carbon Stee* K mm C.A /Sour e6terna**coate# it9 14;Lm T9erma**- Spra-e#

Carbon Stee* K 3mm C.A /Sour e6terna**- coate# it9 14;Lm

+a'e 

*+uipment Name


A%ternatives

A*uminium an# sea*e# usin' an A*:-# Si*icone topcoat.

T9erma**- Spra-e# A*uminium an# sea*e# usin' an A*:-# Si*icone top coat B

Test ea#er

Carbon Stee* K 8mm C.A /Sour e6terna**coate# it9 14;Lm T9erma**- Spra-e# A*uminium an# sea*e# usin' an A*:-# Si*icone topcoat.

Carbon Stee* K 3mm C.A /Sour e6terna**- coate# it9 14;Lm T9erma**- Spra-e# A*uminium an# sea*e# usin' an A*:-# Si*icone top coat. B

%6port +i' (aunc9er


%6port (ast >a*ve On

Carbon stee* bo#- it9 Incone* 2" over*afor ette# parts.

%6port +ipe*ine

DN> OS )1;1 S!( &ra#e 1" ISD K mm C.A. /i.e. Seam*ess7 ; stren't9 *inepipe for sour service an# improve# #imensiona* contro*.

1 DN> OS )1;1 S!( &ra#e 1" ISD K 3mm C.A. /i.e. Seam*ess7 ; stren't9 *inepipe for sour service an# improve# #imensiona* contro*  2 DN> OS )1;1 ), &ra#e 1" ISD K mm C.A. /i.e. i'9 )re@uenc- ,e*#e#7 ; stren't9 *inepipe for sour service an# improve# #imensiona* contro*1.

%6port +ipe*ine Riser

DN> OS )1;1 S!( &ra#e 1" ISD K mm C.A. %6terna* sp*as9 Jone protection usin' CS s*eeve 12mm it9 !one* ;; c*a##in' /3mm

DN> OS )1;1 S!( &ra#e 1" ISD K 3mm C.A. %6terna* sp*as9 Jone protection usin' CS s*eeve 12mm it9 !one* ;; c*a##in' /3mm &

%6port +ipe*ine Riser DN> OS )1;1 S!( &ra#e 1" ISD K mm at  C.A. %6terna* sp*as9 Jone protection usin' CS s*eeve 12mm it9 !one* ;; c*a##in' /3mm

DN> OS )1;1 S!( &ra#e 1" ISD K 3mm C.A. & streams /#ue to *oer arriva* temperatures M 4;C %6terna* sp*as9 Jone protection usin' po*-c9*oroprene rubber 12mm t9ic:.

)ue* &as S-stem

Carbon Stee* K 3mm /Sour

)ue* &as S-stem >a*ves

Carbon Stee* it9 31( trim

Open Drain (ines

&R+BC

Carbon Stee* K mm C.A

1

+a'e "

*+uipment Name


A%ternatives

Open Drain >a*ves

Nic:e* A*uminium =ronJe

Rubber *ine# carbon stee*

Open Drain >esse* /Sump

UNS S322;" Dup*e6 Stain*ess Stee*

If a *ar'er #iameter vesse* can be accommo#ate#. T9en a 9eav- a** t9ic:ness carbon stee* #rain vesse*7 it9 removab*e eirs7 an# interna**coate# it9 a &*ass )*a:e epo6- i** be acceptab*e.

Open Drain +ump

Carbon Stee* it9 Stain*ess Stee* impe**er

>ent an# C*ose# Drain (ines

Carbon Stee* K 3mm C.A

C*ose# Drain >a*ves

Carbon stee* it9 31( trim

>ent Scrubber >esse*

Carbon stee* it9 interna* '*ass f*a:e epo6coatin' or =e*Jona 1351 coatin'

>ent Scrubber +ump

Carbon Stee* it9 Stain*ess Stee* impe**er

-#rau*ic +ipin'

AST! A25 &ra#e 31( it9 min 2." !o

If TP;QC 2" Cr super #up*e6 /UNS S328"; or aste**o- C28 /UNS N1;28

Instrument Tubin'

AST! A25 &ra#e 31( it9 min 2." !o

If TP;QC 2" Cr super #up*e6 /UNS S328"; or aste**o- C28 /UNS N1;28

Instrumentation

Refer to Tab*e 4 B12 on pa'e 3

,as9 Don ,ater Tan: an# +ipin'

&R+BC it9 31( tan: fittin's

+o*-prop-*ene

,as9 Don S-stem >a*ves

Nic:e* A*uminium =ronJe

+o*-prop-*ene orH &R+

T9e current #esi'n basis #oes not provi#e for permanent 'as *ift *aunc9ers an# receiversH t9is arran'ement is satisfactor- if corrosion in9ibition is continuous*- injecte# into t9e 'as *ift pipe*ines. If t9e corrosion in9ibition is to be on*- injecte# 9en t9e 'as *ift 'as 'oes off #e point /et 'as operation t9en it is recommen#e# t9at permanent *aunc9ers an# receivers are insta**e# to permit perio#ic seepin' of free ater from t9e 'as *ift pipe*ine an# runnin' batc9 corrosion in9ibitor. T9e

+a'e 

corrosion a**oance for t9e 'as *ift pipe*ines assume t9at t9e pipe*ine i** be operate# for no more t9an ; #a-s per -ear it9 offBspecification 'as. Operation of t9e pipe*ine it9 et 'as for perio#s *on'er t9an ; #a-s per annum i** resu*t in corrosion #ama'e 'reater t9an 3.;mm over t9e 2;B-ear #esi'n *ife. Section 4 an# 5 present furt9er #etai* on t9e topsi#e an# pipe*ine materia* se*ection. It is a*so note# t9at as t9e basis of t9e pipe*ine #esi'n is to be Dn> OS )1;1 t9en it is a re@uirement to pro#uce a )racture Contro* +*an to #efine t9e minimum materia* propert- re@uirements /e' C9arpva*ues for t9e *ine pipe specification.

+a'e 8

3.

D*SI,N D ATA

3.1

Sources of Data

T9e fo**oin' #ata as use# to bui*# t9e corrosivit- mo#e*s an# to revie corrosion re*iabi*it- mo#e*s an# tota* corrosion #ama'e  corrosion a**oance ca*cu*ations. )*orates an# temperatures 9ave been obtaine# from t9e Desi'n =asis Ref 1. Temperature an# pressure profi*es ere obtaine# from t9e base case0 temperatureBpressure profi*es provi#e# in Appen#i6 1 of t9is report. +ipe*ine siJin' for t9e 'as *ift an# e6port pipe*ines ere obtaine# for &ra#e 1"!+a *inepipe from ca*cu*ation s9eet

3.2

Desi -n ife

Desi'n *ife is 2; -ears. +ro#uction profi*es an# 9ence corrosion rates 9ave been mo#e**e# for t9e fo**oin' perio#s over t9e #esi'n *ife •

$ears 1 an# 2 /2;;4B2;1;H

•

$ears 3 to 8 /2;11B2;1"H an#

•

$ears 4 to 2; /2;1B2;24.

3.3

/%ui# Composit ions

3. 3. 1

O i% Composi ti on

A basis composition of t9e pro#uce# f*ui#s 9as been assume# in accor#ance it9 Tab*e .3 in t9e Desi'n =asis Ref 1. T9e critica* components are as fo**os •

CO2 Content  " B 1; t7 assume# 1; for corrosion mo#e*s.

•

2S Content  2; B 1;;;ppm.

3 .3. 2

, as i ft Co mp os it io n

&as *ift composition is in accor#ance it9 Desi'n =asis Section ".1 Ref 1 an# t9e critica* components are as fo**os •

CO2 Content  4 tH

•

2S Content  1;;;ppm.

3 .3 .3

0 ro #u ce # at er An a% 's is

A pro#uce# ater ana*-sis base# on +) fi*e# #ata is presente# Desi'n =asis. T9e critica* components for corrosion mo#e**in' an# materia*s se*ection are as fo**os •

=icarbonate  15;.42 m'( an# 182."m'(7 assume# app*icab*e for  an#  p*atforms respective*- for corrosion mo#e**in' purposesH

•

Ionic Stren't9  "; '(

•

Densit-  1.;"2 '(7 assume 1;"; :'m 37 9ic9 is t9e NORSOG mo#e* *imit an# mo#e* foun# to be to*erant of *ar'e c9an'es in #ensit- it9out effect on t9e corrosion rate7 so mo#e* *imit is not si'nificant.

+a'e 4

•

C9*ori#e content  212.3 m'( to ";.3m'(7 ta:en as ";;m'( for materia*s se*ection purposes. Tab%e 3&2 0ro#uce# ater Ana%'sis ANA$SIS NO.

24253

2433

+= V 8

+& V 3

(it9ium /(i m'*

4.13

5.45

=oron /= m'*

"5.54

8;.34

Si*icon /Si m'*

1".;8

1".28

A*uminium /A* m'*

;.;;

;.11

+9osp9orous /+

N.D.

N.D.

N.D.

N.D.

(ea# /+b

N.D.

N.D.

Ca*cium /Ca m'*

.;

";.25

!a'nesium /!' m'*

12.22

21.18

=arium /=a m'*

;.2

;.2

Strontium /Sr m'*

4."3

.";

Tota* Iron m'*

;.;2

;.31

So#ium /Na m'*

;31

;23

+otassium /G m'*

8.13

12

Carbonate /m'*

.4"

"4."

=icarbonate /m'*

15;.42

182."

C9*ori#e /C* m'*

212.3

";.3

Densit- /'m*

1.;"2

1.;"32

Resistivit- /o9ms

;.;838

;.;

8.84

8."5

Tota* Disso*ve# So*i#s

1;;82.;

111.;

Disso*ve# CO2 /m'* WW

3.3"

2.5

Disso*ve# 2S m'*W

N.D.

N.D.

M;.1

M;.1

N.D.

N.D.

Ta:en from /source

p

Determination of resi#ua* p9osp9ates /Test met9o# for resi#ua* p9osp9ate  C9ampion 2121 Or-anic Aci#

)ormic aci# content

+a'e 5

Acetic aci# content

;.23 m'*

;.2" m'*

+ropionic aci# content

N.D.

N.D.

=ut-ric aci# content

N.D.

N.D.

Note N.D.  not #etecte#7 #etection *imit ;.;1; m'*7 #etection *imit ;.1 m'* for W an# #etection *imit 1.; m'* for WW

3.

0ressures an# Temperatures

Temperature an# pressure profi*es for t9e pipe*ines ere obtaine# from t9e base case0 temperatureB pressure profi*es provi#e# in Appen#i6 1 of t9is report. T9e fo**oin' pressures an# temperatures ere use# for t9e topsi#es an# e**9ea# assessments •

1XST+  2;;; psi'

•

2XST+  21;;psi'

•

3X)T+  24;psi'

•

X)T+  24; psi'

•

separator pressure  23; psi'

•

!a6imum )TT an# topsi#e temperatures  11;QC

3."

Avai%abi%it'

%@uipment avai*abi*it- is state# in t9e -#ra Desi'n =asis as 54 for t9e topsi#es faci*ities an# t9erefore a uti*ities an# process e@uipment avai*abi*it- of 55 is re@uire#. T9e use of 54 avai*abi*it9as been a#opte# for t9e corrosion in9ibition s-stem. T9e faci*itre@uirement to ac9ieve a 54 corrosion in9ibition s-stem avai*abi*it- is #iscusse# in Section ".2.3.

3.4

Corrosion !o#e% Cases

3 .4. 1

, as i ft 6 37 8 0i pe% in e

(( 0%atform

29 to 21

211& 21"

+ipe Diameter

44.5mm

+ipe ,a** T9ic:ness

".1mm

Insi#e Diameter

84.8mm

,t CO2

214 : ;e'on#

4.;

4.;

4.;

Temperature  In*et

;QC

;QC

;QC

Temperature B Out*et

28QC

28QC

28QC

+a'e 1;

&as  (i@ui#  !u*tip9ase

De9-#rate# 'as7 possibi*it- of intermittent et 'as.



12"; psi'

12"; psi'

12"; psi'

;.18 !Sm3#

;.18 !Sm3#

;.18 !Sm3#

Oi* Rate

;

;

;

,ater Rate

;

;

;

;.;1 Sm3#a-

;.;1 Sm3#a-

;.;1 Sm3#a-

,ater Cut

;

;

;

In9ibitor %fficienc-2

5"

5"

5"

29 to 21

211& 21"

214 : ;e'on#

+ressure &as )*orate

(i@ui#s )*orate 1

(( 0%atform

+ipe Diameter

44.5mm

+ipe ,a** T9ic:ness

".1mm

Insi#e Diameter

84.8mm

,t CO2

4.;

4.;

4.;


;QC

;QC

;QC

Temperature  Out*et

28QC

28QC

28QC




12"; psi'

12"; psi'

12"; psi'

;.18 !Sm3#

;.18 !Sm3#

;.18 !Sm3#

Oi* Rate

;

;

;

,ater Rate

;

;

;

;.;1 Sm3#a-

;.;1 Sm3#a-

;.;1 Sm3#a-

,ater Cut

;

;

;


5"

5"

5"




Notes

+a'e 11

1. )or NORSOG !";7 *i@ui#s f*orate must be 'reater t9an ;. Assume# ;.;1 Sm 3#a- for orstBcase consi#erations. &as *ift 'as i** be #e9-#rate# on t9e 66 p*atform an# ma- from time to time be e6porte# over t9e #e point specification for t9e 'as. 2. In9ibitor efficienc- assume# to be *oer t9an is t-pica* for t9e C9ampion Tec9no*o'ies Crono6 in9ibitors use# t9rou'9out t9e 66 an# 66 fie*#s as continuous in9ibition is not anticipate# for t9is *ine. In9ibition s9ou*# be s*u''e# #ose# perio#ica**- an# continuous*- injecte# on*- 9en it is e6porte# from 66 over t9e 'as *ift #e point specification.

3 .4. 2

, as i ft 6 7 8 0i pe% in e

(( 0%atform

29 to 21

211& 21"

+ipe Diameter

11.3mm

+ipe ,a** T9ic:ness

.mm

Insi#e Diameter ,t CO2

214 : ;e'on#

1;1."mm 4.;

4.;

4.;


;QC

;QC

;QC


28QC

28QC

28QC




121" psi'

121" psi'

121" psi'

;.18 !Sm3#

;.18 !Sm3#

;.18 !Sm3#

Oi* Rate

;

;

;

,ater Rate

;

;

;

;.;1 Sm3#a-

;.;1 Sm3#a-

;.;1 Sm3#a-

,ater Cut

;

;

;


5"

5"

5"

29 to 21

211& 21"

214 : ;e'on#



(( 0%atform


+ipe Diameter

11.3mm

+ipe ,a** T9ic:ness

.mm

Insi#e Diameter ,t CO2

1;1."mm 4.;

4.;

+a'e 12

4.;


;QC

;QC

;QC


28QC

28QC

28QC





118" psi'

118" psi'

118" psi'

;.18 !Sm3#

;.18 !Sm3#

;.18 !Sm3#

Oi* Rate

;

;

;

,ater Rate

;

;

;

;.;1 Sm3#a-

;.;1 Sm3#a-

;.;1 Sm3#a-

,ater Cut

;

;

;


5"

5"

5"



Notes 1. )or NORSOG !";7 *i@ui#s f*orate must be 'reater t9an ;. Assume# ;.;1 Sm 3#a- for orstBcase consi#erations. &as *ift 'as i** be #e9-#rate# on t9e 66 p*atform an# ma- from time to time be e6porte# over t9e #e point specification for t9e 'as. 2. In9ibitor efficienc- assume# to be *oer t9an is t-pica* for t9e C9ampion Tec9no*o'ies Crono6 in9ibitors use# t9rou'9out t9e 66 an# 66 fie*#s as continuous in9ibition is not anticipate# for t9is *ine. In9ibition s9ou*# be s*u''e# #ose# perio#ica**- an# continuous*- injecte# on*- 9en it is e6porte# from 66 over t9e 'as *ift #e point specification.

3 .4 .3

, as  if t
(( 0%atform

29 to 21

211& 21"

+ipe Diameter

44.5mm

+ipe ,a** T9ic:ness

".1mm

Insi#e Diameter

84.8mm

,t CO2

214 : ;e'on#

4.;

4.;

4.;


28QC

28QC

28QC


B

B

B

+a'e 13





121" psi'

121" psi'

121" psi'

;.18 Sm3#

;.18 Sm3#

;.18 Sm3#

Oi* Rate

;

;

;

,ater Rate

;

;

;

;.;1 Sm3#a-

;.;1 Sm3#a-

;.;1 Sm3#a-

,ater Cut

;

;

;


5"

5"

5"

29 to 21

211& 21"

214 : ;e'on#



(( 0%atform

+ipe Diameter

44.5mm

+ipe ,a** T9ic:ness

".1mm

Insi#e Diameter

84.8mm

,t CO2

4.;

4.;

4.;


28QC

28QC

28QC


B

B

B





118" psi'

118" psi'

118" psi'

;.18 Sm3#

;.18 Sm3#

;.18 Sm3#

Oi* Rate

;

;

;

,ater Rate

;

;

;

;.;1 Sm3#a-

;.;1 Sm3#a-

;.;1 Sm3#a-

,ater Cut

;

;

;


5"

5"

5"



Notes

+a'e 1

1. )or NORSOG !";7 *i@ui#s f*orate must be 'reater t9an ;. Assume# ;.;1 Sm 3#a- for orstBcase consi#erations. &as *ift 'as i** be #e9-#rate# on t9e  p*atform an# ma- from time to time be e6porte# over t9e #e point specification for t9e 'as. 2. In9ibitor efficienc- assume# to be *oer t9an is t-pica* for t9e C9ampion Tec9no*o'ies Crono6 in9ibitors use# t9rou'9out t9e 66 an# 66 fie*#s as continuous in9ibition is not anticipate# for t9is *ine. In9ibition s9ou*# be s*u''e# #ose# perio#ica**- an# continuous*- injecte# on*- 9en it is e6porte# from 66 over t9e 'as *ift #e point specification.

3 . 4. 

0 r o #u c ti o n / % o =% i n es 6 4 o f f 8 a n # T es t < e a# e rs

(( 0%atform

29 to 21

211& 21"

+ipe Diameter

14.3mm

+ipe ,a** T9ic:ness

1;.58mm

Insi#e Diameter

1.3mm

,t CO2

214 : ;e'on#

1;

1;

1;


11;QC

11;QC

11;QC


11;QC

11;QC

11;QC


!u*tip9ase

!u*tip9ase

!u*tip9ase

15. =ar

15. =ar

&as )*orate

;.1 !Sm3#a-

;.13 !Sm3#a-

;.12 !Sm3#a-

Oi* )*orate

5" Sm3#a-

85" Sm3#a-

88 Sm3#a-

,ater )*orate

1282 Sm3#a-

85. Sm3#a-

3185.8 Sm 3#a-


222 Sm3#a-

"". Sm3#a-

3".8 Sm 3#a-

,ater Cut

Note 2

Note 2

Note 2


5"

5"

5"

29 to 21

211& 21"

214 : ;e'on#

+ressure

(( 0%atform

+ipe Diameter

14.3mm

+ipe ,a** T9ic:ness

1;.58mm

Insi#e Diameter

1.3mm

,t CO2

1;

1;

+a'e 1"

15. =ar

1;


11;QC

11;QC

11;QC


11;QC

11;QC

11;QC


!u*tip9ase

!u*tip9ase

!u*tip9ase

15. =ar

15. =ar

;.;43 !Sm 3#a-

;.11 !Sm3#a-

;.1; !Sm3#a-

Oi* )*orate

88 Sm3#a-

314 Sm3#a-

1"5 Sm3#a-

,ater )*orate

88 Sm3#a-

234" Sm3#a-

1282 Sm3#a-


5" Sm3#a-

28;3 Sm3#a-

131 Sm3#a-

,ater Cut

Note 2

Note 2

Note 2


5"

5"

5"


15. =ar

Notes 1. (i@ui#s f*orate is #ivi#e# even*- over  f*o*ines7 i.e. 5"Sm3#a- #ivi#e# b-   1"5Sm3#a-. 2. ,ater cut provi#e# in t9e #esi'n basis as 1;B5;. A revie of t9e effect on ater cut on t9e corrosion mo#e* as performe# an# foun# to 9ave insi'nificant effect. Assume# to be ";. 3. In9ibitor efficienc- assume# to be 5" /a*so mo#e**e# for 5; an# 5" as mi6in' i** sti** be occurrin' from t9e c9o:e va*ves an# ma- not provi#e comp*ete covera'e for t9e first " to 1; #iameters of t9e f*o*ine.

3 .4. "

0 ro #u cti on
(( 0%atform

Up to 21

211& 21"

+ipe Diameter

323.5mm

+ipe ,a** T9ic:ness

18.4mm

Insi#e Diameter

244.5mm

,t CO2

214 : ;e'on#

1;

1;

1;


11;QC

11;QC

11;QC


11;QC

11;QC

11;QC


!u*tip9ase

!u*tip9ase

!u*tip9ase

+a'e 1

+ressure

2;.4 =ar

2;.4 =ar

&as )*orate

;.1 !Sm3#a-

;.13 !Sm3#a-

;.12 !Sm3#a-

Oi* )*orate

5" Sm3#a-

85" Sm3#a-

88 Sm3#a-

,ater )*orate

1282 Sm3#a-

85. Sm3#a-

3185.8 Sm 3#a-

(i@ui#s )*orate

222 Sm 3#a-

"". Sm3#a-

3".8 Sm 3#a-

,ater Cut

Note 2

Note 2

Note 2

In9ibitor %fficienc-/3

5"

5"

5"

(( 0%atform

29 to 21

211& 21"

214 : ;e'on#

+ipe Diameter

323.5mm

+ipe ,a** T9ic:ness

18.4mm

Insi#e Diameter

244.5mm

,t CO2

2;.4 =ar

1;

1;

1;


11;QC

11;QC

11;QC


11;QC

11;QC

11;QC


!u*tip9ase

!u*tip9ase

!u*tip9ase

15. =ar

15. =ar

;.;43 !Sm 3#a-

;.11 !Sm3#a-

;.1; !Sm3#a-

Oi* )*orate

88 Sm3#a-

314 Sm3#a-

1"5 Sm3#a-

,ater )*orate

88 Sm3#a-

234" Sm3#a-

1282 Sm3#a-


5" Sm3#a-

28;3 Sm3#a-

131 Sm3#a-

,ater Cut

Note 2

Note 2

Note 2


5"

5"

5"


15. =ar

Notes 1. (i@ui#s f*orate is #ivi#e# even*- over  f*o*ines7 i.e. 5"Sm3#a- #ivi#e# b-   1"5Sm3#a-. 2. ,ater cut provi#e# in t9e #esi'n basis as 1;B5;. A revie of t9e effect on ater cut on t9e corrosion mo#e* as performe# an# foun# to 9ave insi'nificant effect. Assume# to be ";. 3. In9ibitor efficienc- assume# to be 5" B refer to section ".2.1.

+a'e 18

3 . 4. 4

* ( p or t 0i p e %i n e s 6 S ea m% e s s  i n ep i p e> , ra # e  1 " ! 0 a8

(( 0%atform

Up to 21

211& 21"

+ipe Diameter

3"".mm

+ipe ,a** T9ic:ness

1.mm

Insi#e Diameter

322.4mm

,t CO2

214 : ;e'on#

1;

1;

1;


11;QC

11;QC

11;QC


"4QC

82QC

8QC


!u*tip9ase

!u*tip9ase

!u*tip9ase

15. =ar

15. =ar

&as )*orate

;.1 !Sm3#a-

;.13 !Sm3#a-

;.12 !Sm3#a-

Oi* )*orate

5" Sm3#a-

85" Sm3#a-

88 Sm3#a-

,ater )*orate

1282 Sm3#a-

85. Sm3#a-

3185.8 Sm 3#a-


222 Sm3#a-

"". Sm3#a-

3".8 Sm 3#a-

,ater Cut

Note 2

Note 2

Note 2


55

55

55

29 to 21

211& 21"

214 : ;e'on#

+ressure

(( 0%atform

+ipe Diameter

3"".mm

+ipe ,a** T9ic:ness

1.mm

Insi#e Diameter

322.4mm

,t CO2

15. =ar

1;

1;

1;


11;QC

11;QC

11;QC


28QC

34QC

3QC


!u*tip9ase

!u*tip9ase

!u*tip9ase

15. =ar

15. =ar

;.;43 !Sm 3#a-

;.11 !Sm3#a-


+a'e 14

15. =ar ;.1; !Sm3#a-

Oi* )*orate

88 Sm3#a-

314 Sm3#a-

1"5 Sm3#a-

,ater )*orate

88 Sm3#a-

234" Sm3#a-

1282 Sm3#a-


5" Sm3#a-

28;3 Sm3#a-

131 Sm3#a-

,ater Cut

Note 2

Note 2

Note 2


55

55

55

Notes 1. (i@ui#s f*orate is #ivi#e# even*- over  f*o*ines7 i.e. 5"Sm3#a- #ivi#e# b-   1"5Sm3#a-. 2. ,ater cut provi#e# in t9e #esi'n basis as 1;B5;. A revie of t9e effect on ater cut on t9e corrosion mo#e* as performe# an# foun# to 9ave insi'nificant effect. Assume# to be ";. 3. In9ibitor efficienc- assume# to be 55 as mi6in' i** be performe# upstream of t9e c9o:e va*ves an# f*o i** be annu*ar  s*u' f*o t9at provi#es fu** pipe ettin'.

3 . 4. ?

* ( p or t 0 i p e% i n es 6< / I  i n ep i p e> ,r a #e  1 "! 0 a8

See Note 1 for t9is service ((0%atform

Up to 21

211& 21"

+ipe Diameter

3"".mm

+ipe ,a** T9ic:ness

13.;mm

Insi#e Diameter

325.mm

,t CO2

214 : ;e'on#

1;

1;

1;


11;QC

11;QC

11;QC


"4QC

82QC

8QC


!u*tip9ase

!u*tip9ase

!u*tip9ase

15. =ar

15. =ar

&as )*orate

;.1 !Sm3#a-

;.13 !Sm3#a-

;.12 !Sm3#a-

Oi* )*orate

5" Sm3#a-

85" Sm3#a-

88 Sm3#a-

,ater )*orate

1282 Sm3#a-

85. Sm3#a-

3185.8 Sm 3#a-

(i@ui#s )*orate

222 Sm 3#a-

"". Sm3#a-

3".8 Sm 3#a-

Notes 3

Note 3

Note 3

+ressure

,ater Cut

+a'e 15

15. =ar

In9ibitor %fficienc((( 0%atform

55

55

55

29 to 21

211& 21"

214 : ;e'on#

+ipe Diameter

3"".mm

+ipe ,a** T9ic:ness

13.;mm

Insi#e Diameter

325.mm

,t CO2

1;

1;

1;


11;QC

11;QC

11;QC


28QC

34QC

3QC


!u*tip9ase

!u*tip9ase

!u*tip9ase

15. =ar

15. =ar

;.;43 !Sm 3#a-

;.11 !Sm3#a-

;.1; !Sm3#a-

Oi* )*orate

88 Sm3#a-

314 Sm3#a-

1"5 Sm3#a-

,ater )*orate

88 Sm3#a-

234" Sm3#a-

1282 Sm3#a-


5" Sm3#a-

28;3 Sm3#a-

131 Sm3#a-

,ater Cut

Notes 3

Note 3

Note 3

In9ibitor %fficienc-

55

55

55


15. =ar

Notes 1. !o#e**e# on*- once to revie effect of *ar'er ID on a** s9ear. %ffect foun# to be ne'*i'ib*e. 2. (i@ui#s f*orate is #ivi#e# even*- over  f*o*ines7 i.e. 5"Sm3#a- #ivi#e# b-   1"5Sm3#a-. 3. ,ater cut provi#e# in t9e #esi'n basis as 1;B5;. A revie of t9e effect on ater cut on t9e corrosion mo#e* as performe# an# foun# to 9ave insi'nificant effect. Assume# to be ";. . In9ibitor efficienc- assume# to be 55 as mi6in' i** be performe# upstream of t9e c9o:e va*ves an# f*o i** be annu*ar  s*u' f*o t9at provi#es fu** pipe ettin'.

3 . 4. 9

0 ro # uc e# a te r * f fe ct !o # e% % in -

T9e effect of pro#uce# ater c9emistr- can be profoun# on t9e corrosion rate #ue to t9e p bufferin' as a resu*t of t9e bicarbonate content of t9e pro#uce# ater. T9e effect of pro#uce# ater c9emistr9as been investi'ate# as part of t9is corrosion stu#-. Initia* mo#e**in' #escribe# b- t9e scenarios above assume# on*- ater of con#ensation is present in t9e pro#uce# *i@ui#s an# t9is resu*ts in *o p pre#ictions. Separate mo#e*s 9ave been run for a** t9e pro#uction si#e assets it9 pro#uce#

+a'e 2;

ater7 9ic9 is c*oser to t9e true pro#uction scenario an# *ess conservative. T9e NORSOG !"; mo#e* uses bicarbonate concentration an# ionic stren't9 to c9aracterise t9e pro#uce# ater c9emistr-. A bicarbonate concentration of 151 m'* for 66 an# 182 m'* for 669as been use# for t9e mo#e*s an# an ionic stren't9 of "; '*7 9ic9 is a t-pica* va*ue for pro#uce# ater. To furt9er c9aracterise t9e pro#uce# ater7 an increase in #ensit- 9as been inc*u#e# in t9e corrosion mo#e*7 #ensit- is 1;"2 :'m 3 for 66an# 667 but as *imite# to 1;"; :'m 37 t9e mo#e*s ater #ensit- *imit. T9e pro#uce# ater c9emistr- #escribe# in Section 3.3.3 is t-pica* of t9e 66 fie*#s an# as ta:en from t9e 66 an# 66 e** ana*-sis. To un#erstan# t9e sensitivit- of t9e corrosion mo#e* to variations in t9e pro#uce# ater c9emistr- a##itiona* mo#e*s 9ave been run to s9o t9e effect on t9e 66 pro#uction e6port pipe*ine at 5; bicarbonate *eve* an# 8" bicarbonate *eve*.

+a'e 21

.

!*T
.1

0otent ia% for Corrosion

 . 1. 1

C or ro si o n ! ec )a ni sm s a n# C o ns i #e ra ti o ns

T9e fo**oin' sections #iscuss t9e corrosion mec9anisms t9at cou*# be e6perience# #urin' t9e *ife of t9e 66 fie*#. T9e factors t9at contribute to t9ese mec9anisms are 9i'9*i'9te# a*on' it9 an assessment of t9e possibi*it- of t9e corrosion mec9anism occurrin' an# 9at can be #one to miti'ate t9e corrosion ris:.

. 1. 2

CO 2 Corrosion

T9e 66 pro#uction f*ui#s contain appro6imate*- 4 ,t CO 2 Ref 1 a*on' it9 ater of con#ensation an# *ater in t9e fie*# *ife7 pro#uce# ater. T9e reaction of CO 2 it9 ater in t9e pipe*ine can resu*t in t9e formation of carbonic an# acetic aci#. T9e carbonic an# acetic aci# re#uces t9e p of t9e pro#uction stream an# at co**ection points /i.e. topo'rap9ic *o points7 #ea# *e's an# sta'nant Jones or at miscibi*it- 'aps t9e aci#ifie# so*ution can cause 'enera* corrosion7 pittin' corrosion an# mesaB t-pe corrosion of stee*s. (oca*ise# corrosion ma- ta:e man- forms7 from pittin' to mesa t-pe attac:7 9ere corrosion appears as *ar'e7 f*atBbottome# *oca*ise# areas of #ama'e. +ittin' maoccur over t9e fu** ran'e of operatin' temperatures un#er sta'nant to mo#erate f*o con#itions. +ittin' rates are a function of temperature7 pressure7 f*o ve*ocit- an# c9aracteristics an# CO 2 concentration7 it9 t9e propensit- for pittin' 9i'9*#epen#ent on t9e c9emistr- an# surface finis9 of t9e stee*. +ittin' ma- arise c*ose to t9e #e point temperature7 an# can be associate# it9 ater of con#ensation an# is often referre# to as Top of (ine Corrosion /TO(C7 refer to Section .1.3. T9ere is no rea* a- of pre#ictin' t9e occurrence an# e6tent of pittin' as oppose# to 'enera* corrosion mec9anisms for stee*. !esa t-pe attac: is a form of *oca*ise# CO 2 corrosion t9at occurs un#er mo#erate f*o con#itions 9ere carbonate sca*es ma- form but are not stron'*- stab*e. T9is form of attac: resu*ts from *oca*ise# spa**in' of t9e carbonate sca*e7 e6posin' t9e un#er*-in' bare meta* surface t9at t9en corro#es. T9e sca*e7 9en forme#7 ma- e6perience 9i'9 intrinsic stresses it9in t9e sca*e fi*m7 resu*tin' in repeate# spa**in' of t9e same area. T9is t-pe of attac: 'enera**- occurs at ;QC to 1;;QC7 as t9e sca*e forme# ten#s to be *ess a#9esive t9an t9ose forme# at temperatures 'reater t9an 1;;QC. !esa attac: ma- a*so resu*t from se*fBsustainin' 'a*vanic reactions beteen passive an# active corrosion fi*ms. )*o in#uce# *oca*ise# corrosion in CO 2 corrosion s-stems starts from corrosion pits7 e*#s or ot9er surface #iscontinuities 9ere *oca*ise# turbu*ence mabe create#. T9e *oca*ise# turbu*ence7 in a##ition it9 stresses containe# it9in t9e 'roin' sca*es7 ma- resu*t in t9e #estruction of e6istin' sca*es7 an# prevent t9e reformation of furt9er protective sca*es. T9is t-pe of corrosion is t-pica**observe# as para**e* 'rooves e6ten#in' in t9e f*o #irection. )*o in#uce# *oca*ise# corrosion maoccur in s-stems it9 re*ative*- 9i'9 f*oin' ve*ocities. T9e CO2 corrosion mec9anism is consi#ere# to be t9e #ominant corrosion mec9anism for t9e -#ra #eve*opment. A mo#e* 9as been use# to ca*cu*ate t9e corrosion as t9e resu*t of CO 2 corrosion of stee*. T9e mo#e* is #iscusse# furt9er in Section .2 an# t9e resu*ts presente# in Appen#i6 2.

+a'e 22

 .1. 3

Top of  in e Co rr osi on

Top of *ine corrosion /TO(C is not a *ar'e prob*em in 'enera*7 but is :non to occur in specific pro#uction situations. TO(C is t9e resu*t of et 'as coo*in' an# a**oin' ater an# 9-#rocarbon to con#ense on t9e top of t9e pipe. )or stratifie# f*o7 *i@ui# 9-#rocarbons an# c9emica* in9ibitors protect t9e *oer portion of t9e pipe7 9ereas t9e top section is unprotecte#. TO(C #epen#s on temperature7 rate of ater con#ensation7 #istribution of corrosion in9ibitor an# t9e f*o re'ime. At ver- 9i'9 con#ensation rates t9e corrosion pro#uct on t9e top surface of t9e pipe is continuous*as9e# aa- an# t9erefore t9ere is not9in' to stif*e t9e corrosion rate. Un#er 9i'9 con#ensation rates t9e rate of corrosion is #irect*- re*ate# to t9e con#ense# ater p. At *oer con#ensation rates t9e corrosion pro#ucts forme# on t9e top of t9e *ine i** stif*e t9e corrosion rate. TO(C ma- on*- be consi#ere# for t9e 'as *ift *ines if t9e 'as e6porte# from t9e  p*atform is not #e9-#rate# proper*- #ue to process upsets or t9e *i:e. T9e e6posure to TO(C is t9erefore consi#ere# *o in t9is case. T9e e6port pipe*ines i** 9ave annu*ars*u''in' f*o re'imes t9at i** ensure corrosion in9ibitor an# oi* is sp*as9e# aroun# t9e entire annu*us of t9e pipe t9ereb- stif*in' corrosion reactions.

 . 1. 

S u% p )i # e S t re ss Co r ro si o n C ra c@ i n-

T9e 2S *eve* of t9e -#ra f*ui#s is si'nificant. T9e environmenta* con#itions #escribe# b- ISO 1"1"  NAC% !R;18" specif- t9at SSCC is not a ris: for carbon stee* materia*s 9en t9e partia* pressure of 2S is *ess t9an ;.;" psi /;.3":+a. )or t9e 'as *ift t9e 2S partia* pressure is 4.:+a an# for t9e pro#uce# *i@ui#s t9e  2S partia* pressure is ;.22:+a. It is t9erefore assume# t9at sour service con#itions prevai* for t9e 'as *ift /even t9ou'9 it is on*- intermittent*- run et an# it is consi#ere# 'oo# practice to assume t9e pro#uce# f*ui#s are sour 'iven t9e accurac- of #ata provi#e# at t9is time. One of t9e causes for fie*# sourin' is t9e resu*t of poor practices #urin' e** intervention or: /e'. t9e use of #ri**in' mu# infecte# it9 su*p9ate re#ucin' bacteria7 9ic9 contaminates t9e formation. Contro*s s9ou*# be imp*emente# b- 66 to prevent t9is from occurrin'. (inepipe #esi'ne# in accor#ance it9 DN> OS )1;1 s9a** be specifie# it9 t9e YSY supp*ementarre@uirements. T9e common*- use# oi* an# 'as in#ustr- materia*s 9ave var-in' responses to t9e presence of  2S. T9ese responses are 'enera**- comp*icate# b- factors suc9 as p7 temperature7 an# t9e presence of c9*ori#es an# free su*p9ur. Accor#in'*-7 ISO 1"1" s9ou*# be consu*te# to ensure materia*s use# in sour service con#itions are acceptab*e un#er t9e prevai*in' 66 con#itions.

 . 1. "

< '# r o- en In # uc e# St r es s C ra c@ i n-

ISC occurs 9en atomic 9-#ro'en 'enerate# b- a corrosion reaction #iffuses t9rou'9 t9e stee* an# t9en accumu*ates as 'aseous /mo*ecu*ar 9-#ro'en at nonBmeta**ic inc*usions7 particu*ar*- 9en t9ese 9ave been f*attene# b- ro**in' or #rain' operations. As more 9-#ro'en enters t9e voi#s t9e pressure rises7 #eformin' t9e surroun#in' stee* so t9at b*isters become visib*e on t9e surface. T9e stee* aroun# t9e crac: or inc*usions in t9e microstructure becomes 9i'9*- straine# an# t9is can cause *in:in' of a#jacent crac:s to form 9at is :no as stepBcrac:s or in#uce furt9er crac:s to form in t9e surroun#in' stress fie*#. Carbon stee*s are susceptib*e to ISC. T9is can occur 9en carbon stee* is e6pose# to  2S. ISC can occur in stee* at muc9 *oer 2S *eve*s t9an SSC *imits set b- NAC% !R ;18"  ISO 1"1". T9ere is no minimum pressure *imit 9ere ISC i** not occur.

+a'e 23

T9e ris: of ISC can be re#uce# b- ensurin' *inepipe carbon stee* is specifie# for sour surface un#er DN> OS )1;1. T9is i** ensure t9ere is contro* of e*ementa* su*p9ur /an# 9ence inc*usions in t9e stee* as e** as subjectin' t9e stee* to testin' to %)C +ub*ication 1 Ref .

 .1 .4

< '# ro -e n * mb ri tt %e me nt

-#ro'en in#uce# crac:in' cause# b- a#sorption of 9-#ro'en forme# at t9e cat9o#e site /bare meta* bein' protecte# as a resu*t of cat9o#ic protection is :non to embritt*e an# in some circumstances crac: t9e parent materia* 9en sufficient resi#ua* or service stresses are present. T9e propensit- for crac:in' is :non to be cr-sta* structure sensitive7 it9 face centre# cubic materia*s /e' austenitic stain*ess stee*s bein' more resistant t9an bo#- centre# cubic materia*s /e.'. carbon stee* an# not *i:e*- to crac: un*ess ver- 9i'9 *eve*s of stren't9co*# or: are #eve*ope#. =o#- centre# an# re*ate# cubic structures are :no to be susceptib*e #epen#in' upon stren't9 /9ar#ness an# #e'ree of co*# or:in' /p*astic strain7 it9 9ar#ness usua**- accepte# as t9e #efinin' propert- as far as propensitto crac:in' is concerne#. Norma* carbon stee*s suc9 as t9ose use# to manufacture DN> OS )1;1 *ine pipe are essentia**- not susceptib*e to %7 #ue to t9e stren't9 *eve*s of t9ese materia*s7 provi#e# t9e 9ar#ness of t9e 9eat affecte# Jones of e*#s are *ess t9an about 3"; >. ar#ness *eve*s above t9is ma- resu*t in crac:in' in t9e A< if t9e 9ar#ene# area is uncoate# an# t9us e6pose# to t9e C+ s-stem. It is pru#ent t9erefore to specif- 9ar#ness *eve*s *ess t9an 3"; > in A< of e*# proce#ure @ua*ification tests an# ), *inepipe manufacturin' specifications. Dup*e6 stain*ess stee*s contain microstructures t9at are susceptib*e to %. T9ere are :non fai*ures of uncoate# super #up*e6 an# #up*e6 stain*ess stee* e@uipment #ue to %. T9ese fai*ures are e6ceptiona* as t9ere 9ave been man- successfu*7 re*ative*- *on' service *ife subsea insta**ations of pipe*ines7 manifo*#s an# simi*ar e@uipment fabricate# from 22Cr #up*e6 stain*ess stee*. T9e fai*ure #etai*s are not i#e*- pub*is9e#7 9oever from recent*- pub*is9e# information /Ref. 47 9-#ro'en embritt*ement in#uce# crac:in' in t9ese t-pes of materia*s appears to be #ue to a number of factors. T9ese factors inc*u#e •

Susceptib*e microstructures t9at are bare surfaces 9ere 9-#ro'en can a#sorb

•

+*astic #eformation pro#uce# #urin' fabrication7 insta**ation an# inBservice cause# b- stresses7 9ic9 ere not pre#icte# or incorrect*- ca*cu*ate#.

It s9ou*# be note# 9oever t9at p*astic #eformation occurrin' 9i*st t9e C+ s-stem is app*ie# /9en submer'e# 9as been consi#ere# t9e most critica* factor to cause crac:in' /Ref. 4. It ou*# appear t9at a 9i'9 inte'rit- coatin' s-stem an# #esi'n to ensure absence p*astic #eformation in service7 /for e6amp*e #ue to pipe*ine instabi*it-t9erma* stresses are essentia* to miti'ate t9is ris: in #up*e6 stain*ess stee* materia*s. In October 2;;"7 NORSOG pub*is9e# a ,or:s9op A'reement as t9e Desi'n 'ui#e*ine to avoi# 9-#ro'en in#uce# stress crac:in' in subsea #up*e6 stain*ess stee*s0 /Ref. 5. T9e :e- #esi'n consi#erations for avoi#in' ISC in #up*e6 stain*ess stee* are as fo**os •

&*oba* principa* strain to be *imite# to Z ;. for #up*e6 stain*ess stee*sH

•

(oca* pea: strain /tota* strain #ue to SCN)s an# resi#ua* strains to be *imite# to Z ;.8H

•

)or'in's s9a** be for'e# as c*ose*- as practicab*e to t9e specifie# s9ape an# siJeH

•

Transition fi**et e*#s s9a** 9ave a ra#ius not *ess t9an one t9ir# of t9e a** t9ic:nessH

+a'e 2

•

+o*-meric coatin' s9a** not be re*ie# upon to re#uce current #eman# an# 9ence ISC as 9o*i#a-s in t9e coatin' i** cause e6cessive 9-#ro'en pro#uction an# 9ence ISC.

•

C+ potentia* is to be *imite# to ;;m> /A'A'C* 9ere t9e #up*e6 e*ements are comp*ete*iso*ate# from items protecte# at 1;";m>

• Austenite spacin' in t9e #up*e6 stain*ess stee*s is to be *imite# to Z 3;Lm. )or 9eav- for'in's

an austenite spacin' of ;Lm s9ou*# be aime# for T9e subsea use of #up*e6 stain*ess stee* is not envisa'e# for t9e -#ra #eve*opment at t9is sta'e.

 . 1. ?

C )% o ri # e S t re ss Co r ro si o n C ra c@ i n-

C9*ori#e stress corrosion crac:in' occurs 9en a susceptib*e materia* is p*ace# un#er a tensi*e *oa# in a c9*ori#e ric9 environment7 i.e. seaater. Near*- a** fabricate# items contain stresses7 be it operatin' pressure stresses7 t9erma* stresses or resi#ua* stresses from e*#in' an# formin'. So it s9ou*# be assume# t9at a** materia*s use# on t9e topsi#es or subsea i** 9ave a certain tensi*e *oa# on t9em for t9e purpose of consi#erin' 9et9er CSCC is a ris:. Carbon stee* is resistant to c9*ori#e stress corrosion crac:in' in t9e temperature ran'e t9at t9e 66 fie*# i** be operatin' in. T9e use of stain*ess stee*s is #escribe# in Section8.17 an# t9ese materia*s var- consi#erab*- from one 'ra#e to t9e ne6t. Ot9er a**o-s t9at mabe se*ecte# for use as f*o*ines an# for t9e subsea comp*etions s9ou*# be se*ecte# in accor#ance it9 #ata supp*ie# b- t9e materia* supp*iers. It is important to note t9at on p*atform topsi#e service a** materia*s i** be coate# it9 a *a-er of c9*ori#es from sea spra-. Surfaces 9eate# b- interna* process temperatures or so*ar ra#iation ten#s to #r- t9e c9*ori#es on t9e surface t9ereb- concentratin' t9e sa*t over time. So se*ection of materia*s must assume a critica* amount of c9*ori#e is a*a-s present an# t9at temperatures ma- e6cee# t9e critica* CSCC temperature for t9e materia* t9rou'9 bein' 9eate# up b- so*ar ra#iation.

. 1. 9

*ro si o n

T9e effect of erosion from entraine# so*i#s in t9e process stream on t9e can#i#ate materia*s is *ess e** #efine# as t9e amount of entraine# so*i#s is not -et :non. T9e erosion ve*ocities s9ou*# be ca*cu*ate# in accor#ance it9 DN> R+;";1 /Ref. " to confirm t9e materia*s se*ecte# for various components t9rou'9out t9e pro#uction an# transportation s-stems are acceptab*e. A more #etai*e# stu#- i** be re@uire# *ater once more information about t9e e** f*ui#s is obtaine# to #etermine actua* erosion ve*ocities. %rosiona* ve*ocit- *imits for CRA materia*s are provi#e# in Section 8.1 for information purposes. In 'enera* terms #up*e6 stain*ess stee*s s9o superior erosion resistance over carbon stee*s.

 .1 .5

S ub se a *( te rn a% C or ro si on

%6terna* corrosion #ue to e6posure to o6-'enate# seaater is e6pecte# for t9e pipe*ines an# especia**- t9e risers. A** of t9e can#i#ate *inepipe materia*s re@uire e6terna* coatin's an# cat9o#ic protection to protect t9em from e6terna* corrosion from t9e seaater environment. Specia* coatin' s-stems for t9e risers are provi#e# in Section 5.2.2.

 . 1 . 1  T op s i # e A t m o sp ) e r i c C o r r o si o n T9e topsi#e e@uipment an# structures i** be e6pose# to a marine environment7 9ic9 can t-pica**resu*t in corrosion of stee* at a rate of appro6imate*- ;.1" to ;.2; mm-ear /3mm to mm in 2; -ears. T9erefore7 a** carbon stee* s9a** be protecte# it9 antiBcorrosion coatin's. ,9ere items are *ocate#

+a'e 2"

suc9 t9at maintenance of t9e coatin' s-stem is #ifficu*t t9em it is recommen#e# t9at eit9er a CRA materia* is use# or a suitab*e corrosion a**oance is app*ie# to account for e6terna* corrosion as e** as interna* corrosion.

 . 1 . 11 C o r r o si o n o f t ) e  i n e 0 i p e D u r i n - Tr a n sp o r t a t i on (inepipe materia*s are invariab*- transporte# from Asia an# %urope via a separate coatin' -ar#. It is #urin' t9e transBs9ipment activities t9at some materia*s are e6pose# to a corrosive marine environment an# sometimes even ra seaater. Carbon stee* 9en e6pose# to a marine environment i** corro#e7 9oever t9e rate is suc9 t9at t9e e6posure time ou*# 9ave to be severa* -ears before si'nificant #ama'e is incurre#. A** of t9e potentia* corrosion mec9anisms #escribe# above can be prevente# b- t9e app*ication of en# caps /not just beve* protectors t9at are firm*- fi6e# to t9e pipe*ine. Stoin' t9e *ine pipe be*o t9e #ec: of t9e s9ip[s 9o*# can a*so re#uce corrosion ris:. T9e vesse* 9o*# s9ou*# be c9ec:e# to ensure it is #r- an# t9e 9o*# #oors s9ou*# be proven to be aterti'9t. T9e app*ication of a ater repe**ent oi* or corrosion in9ibitor is a*so recommen#e# as part of t9e transportation proce#ure.

 . 1. 1 2 ! i cr o b ia % % ' I n #u c e # C o rr o si o n Contamination of f*o*ines it9 anaerobic bacteria an# t9e resu*tant microbia**- in#uce# corrosion /!IC can ren#er f*o*ines unserviceab*e in ver- s9ort perio#s. T9e microbia* contamination of subsea pipe*ines is common*- attribute# to ba# e** or:Bover practices 9ere contaminate# #ri**in' mu#s are use# an# su*p9ateBre#ucin' bacteria is intro#uce# to t9e formation. Anot9er reco'nise# cause is t9e inappropriate or nonBe6istent treatment of seaater use# for preBcommissionin'. T9at is to sa- insufficient bioci#e concentrations 9ave been app*ie# to t9e ater use# to f*oo# t9e f*o*ine an# t9e bacteria estab*is9 t9emse*ves once t9e pro#uction f*ui#s are transmitte# t9rou'9 t9e f*o*ine. In or#er to estab*is9 t9em an# cause !IC t9e- must 9ave an anaerobic environment an# some nutrient sourceH t-pica**- su*p9ate ions from pro#uce# ater7 in t9e case of su*p9ate re#ucin' bacteria. T9ese microbes t-pica**- become active at temperatures be*o about "C7 an# are :non to corro#e corrosion resistant a**o-s as e** as carbon stee*s. As suc9 a** t9e can#i#ate materia*s are e@ua**susceptib*e to t9is t-pe of corrosion mec9anism. T9e on*- a- of preventin' t9is form of attac: in anaerobic f*o*ine environments be*o "C is b- e6c*u#in' t9e bacteria from t9e f*o*ine environment or preventin' nutrient from bein' provi#e#. Once t9ese microbes become estab*is9e# an# form co*onies an# associate# bioBmasses7 t9e on*- a- of mana'in' t9eir presence is b- t9e intro#uction of bioci#es in or#er to contro* t9eir numbers an# t9erefore t9e corrosion rates. T-pica**t9is is #one b- continuous injection of bioci#es at appropriate concentrations of t9e or#er of 2;B; ppm #epen#in' upon ra c9emica* activit-. T9e- can a*so be contro**e# t9rou'9 batc9 #osin' bintro#ucin' ver- 9i'9 concentrations of bioci#e in s*u's beteen pi's or intro#uction of concentrate# amounts of bioci#e into re*ative*- *o vo*umes of pro#uce# ater /P27;;; ppm. T9e *ar'est ris: comes from preBcommissionin' f*oo#in' of t9e pipe*ine it9 seaater. Con#ense# ater i** not contain su*p9ate ions or ot9er nutrient sources an# s9ou*# serve to f*us9 an- bacteria t9rou'9 t9e pipe*ine. Carbon stee* *inepipe s9ou*# be c*eare# of an- interna* sca*e b- pi''in' as part of t9e commissionin' proce#ures. T9is i** re#uce t9e amount of sites 9ere bacteria can become *o#'e#. ,9ere #up*e6 or super #up*e6 stain*ess stee* is use#7 t9e f*us9in' effect of t9e f*ui#s i** be en9ance#7 as t9ere i** be no surface sca*e 9ere t9e bacteria can *o#'e. As a contin'enc- t9ere nee#s to be faci*ities ma#e avai*ab*e to inject bioci#e into t9e pipe*ine via t9e c9emica* injection *ines. In or#er to miti'ate t9e ris: in 'enera* t9e insta**ation proce#ures nee# to be co'niscent of t9e issues of bacteria contamination7 it9 measures to ensure appropriate *eve*s of bioci#e it9in t9e f*oo#in'

+a'e 2

ater7 contro* measures #urin' tieBins to ensure ra seaater in'ress is :ept to a minimum an# t9at resi#ua* bioci#e *eve*s are sufficient to :i** bacteria intro#uce# in t9is manner. Ot9er measures suc9 as intro#ucin' s*u's of bioci#e beteen pi's #urin' t9e #eaterin' activities are a*so recommen#e#. Operationa* proce#ures nee# to ensure t9at ater pro#uce# it9in t9e first fe mont9s of pro#uction is c9ec:e# for bacteria an# if foun#7 appropriate treatment proce#ures app*ie#.

 . 1. 1 3 U n # er D e po s i t Co r r os i o n Un#er #eposit corrosion is 9ere so*i# materia*s suc9 as reservoir san#s7 corrosion pro#ucts an# sca*e or mi** sca*e sett*e out of so*ution in areas of *o or sta'nant f*o. T9e #eposits of so*i# materia* ten# to s9ie*# t9e materia* be*o from t9e beneficia* effects of corrosion in9ibitors an# protective sca*es. T9e #eposits a*so create a 'a*vanic #ifferentia* potentia* beteen t9e covere# area an# t9e areas covere# b- t9e surroun#in' bu*: f*ui#s7 t9is *ea#s to acce*erate# corrosion of t9e un#er*-in' materia*. T9e #eposits are a*so :non to be 'oo# starter sites for microbia* popu*ations an# can resu*t in rapi# corrosion rates #ue to !IC as #iscusse# in Section .1.12. UDC is common*- incurre# b- carbon stee*s an# t9e austenitic stee*s7 but can a*so be foun#7 to a muc9 *esser e6tent #ue to t9eir 9i'9er to*erance7 in t9e 9i'9er a**o- #up*e6 stain*ess stee*s an# nic:e* a**o-s. T9e 'overnin' #esi'n princip*e for avoi#in' UDC is to first*- e*iminate so*i#s from t9e s-stem 9ere possib*e t9rou'9 t9e use of s*u' catc9ers7 separators or fi*ters. T9e e*imination of #ea# *e's an# sta'nant Jones is a*so consi#ere# an important part of re#ucin' t9e UDC ris: an# t9is is #iscusse# in Section .1.1". ,9ere so*i#s are e6pecte# to #rop out of so*ution t9en faci*ities s9ou*# be provi#e# to a**o t9e c*eanBout of t9at area or for pipe*ines t9en t9e pipe*ines s9ou*# be routine*- c*eane# usin' a c*eanin' pi'.

 . 1. 1  , a % va n i c C o rr o si o n &a*vanic corrosion occurs 9en to7 or more7 #issimi*ar meta*s are p*ace# in e*ectrica* contact in t9e presence of a con#uctive an# corrosion e*ectro*-te /e' sea ater or 9i'9 9umi#it- marine atmosp9eres. T9e materia* t9at is more e*ectrone'ative i** corro#e in preference to t9e a#joine# materia* 9en in t9e presence of an e*ectro*-te. T9is resu*ts in corrosion formin' aroun# t9e joint beteen t9e to materia*s. T9e rate an# e6tent of t9e corrosion is 'overne# b- t9e fo**oin' factors •

T9e 'a*vanic potentia* #ifference beteen t9e materia*sH

•

T9e resistance of t9e contact beteen t9e materia*s an# resistance of t9e e*ectro*-teH

•

T9e e*ectroc9emica* :inetics of t9e corrosion processes in t9e e*ectro*-teH

•

T9e re*ative e6posure of t9e materia*s to t9e e*ectro*-te7 i.e. e6posure of cat9o#ic materia* versus ano#ic materia* /t9e materia* t9at i** corro#e an# t9e #istances beteen t9e e6pose# materia*sH

•

T9e presence of barriers beteen t9e e6pose# materia*s suc9 as coatin's an# fi*ms t9at prevent ionic f*o t9rou'9 t9e bu*: e*ectro*-te beteen t9e bu*: materia*sH

Dissimi*ar meta* joints s9ou*# be avoi#e# 9erever practica*. ,9ere it is unavoi#ab*e t9en t9e in#ivi#ua* joint #etai*s s9ou*# be assesse#. Options suc9 as t9e provision of insu*atin' joints or coatin's s9ou*# be consi#ere#. Iso*atin' joints are often ina#vertent*- s9ort circuite# on offs9ore p*atforms #ue to bri#'in' t9e iso*ate# joint beteen pipe supports or rac:s7 9ic9 are e*ectrica**continuous it9 t9e un#er*-in' structure.

+a'e 28

Coatin's are use# to re#uce t9e re*ative cat9o#ic to ano#ic surface area. It is often a 'oo# i#ea to coat t9e cat9o#ic materia* /t9e more nob*e materia* instea# of t9e ano#ic materia* so t9at s9ou*# a 9o*i#a- form in t9e coatin' coverin' t9e ano#ic materia* it #oes not suffer corrosion from a *ar'e #ifferentia* in current #ensit- create# b- a ver- *ar'e cat9o#e versus a sma** ano#e.

 . 1 . 1 " C o r r o si o n i n De a #  e- s a n # S t a - n a nt  o n e s In et 'as s-stems corrosion can be abnorma**- 9i'9 9ere ater of con#ensation is co**ecte# in areas of *o f*o or vertica* #ea# *e's. In et oi* s-stems ater can set out of t9e main f*o an# be capture# in sta'nant areas or vertica* #ea# *e's. Corrosion in9ibitors often #o not protect t9ese areas of *o f*o or sta'nanc- an# corrosion is e6acerbate# b- t9e presence of #eposits an#or microbacteria. T9e #esi'n of pipin' an# process e@uipment s9ou*# ensure t9at instrument *ines an# tees to areas not norma**- f*oin' be oriente# vertica**- upar# an# not #onar#s. ,9ere *ines are s*o f*oin'7 t9en t9e *ine s9ou*# be #esi'ne# to se*fB#rain an# vesse*s s9ou*# be #esi'ne# suc9 t9at t9ere are no sta'nant Jones or are capab*e of bein' #raine#. Areas of intermittent f*o suc9 as t9e open an# c*ose# #rain s-stems are often affecte# b- sta'nant areas an# particu*ar care s9ou*# be ta:en to ma:e t9e s-stem free #rainin'.

. 2

Se %e ct ion of a Corros ion !o#e%

. 2. 1

, enera%

T9ere are a number of mo#e*s use# to pre#ict corrosion cause# b- CO 2 in et 'as. !ost mo#e*s are proprietar- an# 'enera**- one# b- one of t9e major oi* companies. Of t9e nonBproprietar- mo#e*s avai*ab*e7 one of t9e most popu*ar is t9e NORSOG !"; CO 2 corrosion mo#e* Ref 3. Revision 2 of t9e NORSOG !"; mo#e* as issue# in Fu*- 2;;" an# 9as been use# for t9e ca*cu*ation of CO 2 corrosion in t9is #ocument. T9e NORSOG mo#e* is an empirica* mo#e* main*- base# on *aborator- #ata for t9e *o temperature ran'e an# a combine# *aborator- an# fie*# #ata set for temperatures above 1;;QC. T9e mo#e* is avai*ab*e via t9e NORSOG eb site an# is base# on !S %6ce* sprea#s9eet routines. T9e mo#e* as #eve*ope# b- t9e Nore'ian oi* companies Statoi*H Nors: -#roH an# Sa'a +etro*eum. T9e basis of t9e mo#e* is 'roun#e# in t9e same or: as t9e De,aar#7 !i**iams an# (otJ Ref 8 stu#ies /i.e. from t9e Institute for %ner'- /I)% (aborator- in Nora-. T9e #ifference beteen t9e NORSOG mo#e* an# De,aar# et a* comes from t9e empirica* #ata #eve*ope# for temperatures 'reater t9an 1;;QC. A more in #ept9 #iscussion on t9e ot9er CO 2 corrosion mo#e*s use# aroun# t9e or*# is provi#e# bN-bor' Ref 1;. T9e ot9er mo#e*s ten# to be proprietar- s-stems avai*ab*e on*- to t9e Universities an# oi* companies responsib*e for t9eir #eve*opment. On*- t9e +re#ict softare from InterCorr an# -#roCorr softare from S9e** ta:es account of t9e effects of 2S sca*es on stif*in' CO2 corrosion. A** t9e ot9er pro'rams use#7 inc*u#in' NORSOG7 #o not ta:e  2S sca*e formation into account. =- not accountin' for t9e sca*es forme# b-  2S t9e corrosion rates pre#icte# b- NORSOG !"; are t9erefore re'ar#e# as conservative. T9e unin9ibite# corrosion rates 9ave been use# to ca*cu*ate an overa** corrosion rate base# on t9e in9ibitor avai*abi*it- an# *ife c-c*e approac9 #escribe# b- Rippon Ref  CR

 f \ CRi K /1Bf \ CRU

9ere CR

 overa** corrosion rate /mm-earH

+a'e 24

CRi

 in9ibite# corrosion rate /mm-ear7 assume# for 'as *ift to be ;.;" mm-ear in accor#ance it9 Tab*e  of Rippon Ref 7 ie a corrosion rate in t9e temperature ran'e M 8;°C an# for pro#uction pipin' an# e6port pipe*ines to be ;.1mm-ear. i.e a corrosion rate in t9e temperature ran'e 8; °CZ TZ12;°CH

CRu

 unin9ibite# corrosion rate as ca*cu*ate# usin' NORSOG !"; /mm-earH

f

 in9ibitor injection s-stem avai*abi*it- factor /;.5;7 ;.5"7 ;.54 an# ;.557 for 3." #a-s7 #ontime per -ear7 14.8" #a-s #ontime per -ear7 8.3 #a-s #ontime per -ear an# 3." #a-s #ontime per -ear respective*-.

T9is is a simp*ifie# approac9 t9at ta:es no account of t9e in9ibitors persistenc- an# assumes t9at pro#uction i** continue #urin' t9is #ontime as e**. T9e avai*abi*it- c9osen for  an#  i** be a tra#e off beteen t9e amount of stee* re@uire# for t9e pipe*ine corrosion a**oance an# t9e amount of e@uipment re@uire# for a 9i'9 re*iabi*it- in9ibitor injection s-stem.

 . 2. 2

 i mi t at i on s o f t ) e C or ro si o n ! o# e%

T9e NORSOG !"; corrosion mo#e* is re'ar#e# t9rou'9out t9e in#ustr- as bein' conservative7 i.e. it over estimates corrosion rates. T9e corrosion rates pre#icte# b- t9e mo#e* #o not ta:e into account t9e effects of 2S7 free o6-'en7 etc. )urt9ermore7 t9e mo#e* is base# on empirica* #ata co**ecte# from t9e Gje**er Seet Corrosion researc9 pro'ram at Institute for %ner'- Tec9no*o'- in Nora-. T9erefore7 t9e ran'e of temperatures is *imite# /2; °C to 1;°C7 CO2 fu'acit- /Note 2 is *imite# /;B1; bar an# p is *imite# /3." to .". T9e -#ra process parameters use# for t9e corrosion mo#e*s a** fit it9in t9e boun#s of t9e mo#e* an# t9erefore t9e resu*ts s9ou*# be it9in t9e re*iab*e ran'e of t9e mo#e*.

 . 2. 3

0 re #i c ti o n o f To p o f i n e C or ro si o n

In or#er to pre#ict t9e probabi*it- of TO(C a process mo#e* nee#s to be #eve*ope# to pre#ict t9e point of con#ensation for eac9 e**. Once t9e point of con#ensation is :non an# a rate of con#ensation is ca*cu*ate# t9en a mo#ifie# #e ,aar#B!i**iams Ref 8 met9o# can be use# as s9on be*o CRTO(C

 )con#ensation.CR

9ere )con#ensation  ;. \ /Con#ensation Rate7 'm2s CRTO(C

 Top of (ine Corrosion Rate

CR

 overa** corrosion rate ca*cu*ate# b- t9e CO 2 corrosion mo#e*.

T9e process #ata at t9is sta'e for -#ra is not sufficient to enab*e t9e #eve*opment of con#ensation mo#e*s. TO(C mabe an issue 9en t9e 'as *ift 'as is e6porte# from t9e  p*atform over t9e #e point specification. TO(C is not e6pecte# to be a prob*em on t9e pro#uction si#e of t9e p*atform as

2

A measure of t9e ten#enc- of a 'as to escape or e6pan#. )u'acit- /f i is t9e pressure va*ue nee#e# at a 'iven temperature to ma:e t9e properties of a nonBi#ea* 'as satisf- t9e e@uation for an i#ea* 'as7 i.e.7 f i  γ i+i 9ere γ i is t9e fu'acit- coefficient an# P is t9e partia* pressure for component i of t9e 'as. )or an i#ea* 'as7 γ i 1. i

+a'e 25

mu*tip9ase *i@ui# it9 an annu*ar t-pe f*o is e6pecte#. T9is i** ensure t9at corrosion in9ibitor is even*- #istribute# across a** interna* surfaces of topsi#e pro#uction pipin' an# t9e e6port pipe*ine. T9e on*- practica* means of #eterminin' 9et9er TO(C is a corrosion ris: ort9- of consi#eration in t9is case is to run O(&A #-namic process simu*ations to #etermine t9e rate of ater con#ensation on t9e top of t9e pipe*ine. T9e O(&A mo#e* s9ou*# a*so be ab*e to s9o 9ere t9e ma6imum con#ensation occurs. )or -#ra t9e TO(C ris: s9ou*# on*- be consi#ere# si'nificant if t9e fo**oin' criterion is e6cee#e# •

Con#ensation rate is *ess t9an 8." 'm 2s /Note 3 in t9e carbon stee* pipe*ineH

!et9o#s to miti'ate TO(C inc*u#e t9e use of #iet9-*amine base# in9ibitors combine# it9 t9e or#inar- amine base# fi*min' in9ibitor an# injecte# as one pro#uct at a treatment rate of ];." B ;.4( per !!SC)#a-. A*ternative*-7 9ere TO(C is #eeme# to be a major ris: t9en CRA materia*s can be use# for t9e first section of t9e pipe*ine unti* after t9e con#ensation 9as comp*ete# an# t9e pro#uction f*ui#s are at e@ui*ibrium it9 t9e seabe# temperature. oever7 t9is is an e6pensive option an# can e6ten# t9e con#ensation Jone #ue to t9e #ifferent t9erma* con#uctivit- of t9e CRA materia*s.

. 3

! ec)ani ca% !at eri a% Se% ect ion

 . 3. 1

; ri t t% e /a ct u re an # * mb ri t t% e me nt

=ritt*e fracture is t9e rapi# fracture of meta*s it9out appreciab*e #eformation. T9e ris: of britt*e fracture is increase# 9en a materia* is e6pose# to temperatures be*o its #ucti*ebritt*e facture transition temperature. T9is temperature varies from materia* to materia* an# is re*iant on t9e cr-sta**o'rap9ic structure of t9e materia*. )or materia*s suc9 as a*uminium7 austenitic stain*ess stee*s an# nic:e* a**o-s7 t9e- 9ave a face centre# cubic /)CC structure7 9ic9 contains a 'reater #e'ree of s*ip p*anes. T9ese s*ip p*anes improve t9e materia*s resistance to britt*e fracture an# as suc9 )CC materia*s are 'enera**- immune to britt*e fracture. !ateria*s suc9 as stee*s7 an# #up*e6 stain*ess stee*s /"; is ferritic 9ave a bo#- centre# cubic /=CC structure7 9ic9 9as on*- *imite# s*ip p*anes an# t9erefore is prone to s9ear fai*ures. T9e temperature at 9ic9 t9e materia* is unab*e to s*ip to a#just to e6terna* forces is ca**e# t9e #ucti*e to britt*e transition temperature. !ateria* se*ection s9ou*# be base# on t9e minimum #esi'n temperature of t9e component un#er consi#eration. )or 'aseous service7 t9e effects of t9e Fou*esBT9ompson effect s9ou*# be consi#ere# 9en #eci#in' on t9e minimum #esi'n temperature for t9e materia*. T9e #esi'n co#es a** specif- a minimum temperature for materia*s. T9ese materia*s can t9en on*- be use# at *oer temperatures if t9e- are impact teste# at t9e *oer temperature usin' t9e C9arp- >Bnotc9 impact test an# or t9e Drop ,ei'9t Tear Test /D,TT /main*- use# for p*ate an# pipe*ine stee*s. )or t9e pipe*ine #esi'n to DN> OS )1;1 t9ere is a re@uirement to pro#uce a fracture contro* p*an. It is recommen#e# t9at t9e principa*s #escribe# in +RCI #ocument +RB3B5113 Ref 11 be consi#ere# 9en #eve*opin' a pipe*ine fracture contro* p*an.

3

)rom t9e e@uations in .2.37 Con#ensation Rate  );. an# )  CR TO(CCR 9ere CRTO(C is assume# to be t9e corrosion a**oance 3mm  2; -ears an# CR is ;.;" mm-ear from t9e corrosion mo#e* )  ;.1"  ;.;"  3. Con#ensation Rate  3.;  ;.  8." 'm 2s

+a'e 3;

. 3. 2

/ at i -ue

T9erma* an# vibration in#uce# fati'ue can be prevente# b- t9e use of appropriate #esi'n stan#ar#s an# materia*s an# t9rou'9 maintenance an# inspection. >ibration in#uce# fati'ue can be e6perience# b- pipe or: attac9e# to rotatin' e@uipment or 9ere ver- 9i'9 f*os are e6perience# t9rou'9 pipin' it9 f*o upsets suc9 as orifice p*ates an#  or ben#s etc. T9is can be prevente# t9rou'9 t9e use of a#e@uate pipe supports7 correct materia* siJin' or t9e use of pu*sation #ampeners. A s-stem s9ou*# be re'u*ar*- monitore# once operation be'ins to ensure areas not consi#ere# at ris: #urin' #esi'n #on[t be'in to vibrate #ue to 9armonics from a#jacent e@uipment or remote sources. A*so7 t9e #esi'n #etai*s suc9 as pipe supports are often *eft off #urin' construction or become *oose it9 time7 resu*tin' in e6cessive vibration of t9e pipin'. It is for t9is reason t9at a re'u*ar inspection re'ime s9ou*# be put in p*ace to c9ec: for vibration an# areas t9at are insufficient*- supporte# or restraine#.

+a'e 31

".

C OR RO SI BI T$ AS S* SS! *N T AN D C OR RO SI ON ! ITI ,ATI ON

". 1

C orrosi vi t' As se ssm ent Res u% ts

T9e corrosivit- assessment s9oe# t9at t9e corrosion rates for t9e 'as *ift pipe*ine7 'as *ift pipin'7 pro#uction pipin' an# e6port pipe*ines can be manufacture# usin' carbon stee* it9 a corrosion a**oance an# continuous /54avai*abi*it- corrosion in9ibition. T9e resu*ts of t9e corrosion mo#e**in' are provi#e# in Appen#i6 2. A conservative approac9 9as been ta:en it9 t9e 'as *ift service assumin' t9at t9ere i** be ater carr- over into t9e pipe*ine from time to time. T9e NORSOG mo#e* assumes t9at t9e 'as *ift 'as is saturate# it9 ater a** of t9e time t9at t9e 'as *ift *ine is f*oin'. oever7 t9is i** not be t9e case an# t9erefore corrosion i** not be active a** of t9e time. To a#just t9e NORSOG corrosion mo#e* to account for t9e #uration t9at 'as is off specification /i.e. et 'as operation it 9as been assume# t9at t9e 'as is et for 2; of t9e time t9e 'as *ift operates /i.e appro6imate*- 8; #a-s per -ear. Durin' et 'as operation it is assume# t9at t9e corrosion in9ibitor s-stem is operationa* an# t9at t9e pipe*ine i** corro#e at t9e in9ibite# rate assumin' an in9ibitor efficienc- of 5" an# an in9ibitor avai*abi*it- of 1;;. In9ibitor efficienc- is assume# at 5" as t9e corrosion in9ibitor i** on*- be intermittent*injecte# an# t9erefore t9ere i** be a #e*a- unti* fu** fi*m t9ic:ness an# in9ibition is ac9ieve#. It is be*ieve# t9at it9 t9e measures #escribe# b- t9is report re'ar#in' operationa* pi''in' an# routine corrosion in9ibition7 t9en it is possib*e t9at t9e corrosion a**oance for t9e 'as *ift s-stem cou*# be :ept to 3mm or *ess. A *ot of or: as #one to revie t9e corrosion a**oance for t9e pro#uction f*o*ines an# t9e pro#uction an# test manifo*#s. T9ese *ines run ver- 9ot /11;QC an# t9erefore corrosion rates can be s*i'9t*- 9i'9er t9an e6pecte# #ue to corrosion in9ibitor performance #roppin'. T9is #rop in performance is ta:en into account usin' t9e *ife c-c*e approac9 a#opte# to ca*cu*ate t9e corrosion a**oances for t9e 66 an# 66 assets. A corrosion in9ibitor efficienc- of 5" for f*o*ines an# 9ea#ers an# 55 for riser an# pipe*ines 9as been consi#ere# an# a corrosion in9ibitor s-stem avai*abi*it- of 54 9as been a#opte# in *ine it9 t9e %@uipment Avai*abi*it-7 section /8..1 of t9e +roject =asis of Desi'n Ref 17 9ic9 re@uires topsi#e faci*ities to be #esi'n for 54 up time. A fu** #iscussion of t9e in9ibitor injection p9i*osop9- is provi#e# in Section ".2.3. T9e -#ra corrosion mo#e* as #eve*ope# on t9e basis of a conservative*- i'norin' t9e p bufferin' #ue to bicarbonate content of an- pro#uce# ater bein' presentH an#7 b inc*u#in' effects of p bufferin' #ue to presence of bicarbonates in t9e pro#uce# ater /base# on 66 an# 6 pro#uce# ater composition. T9e pro#uce# ater ana*-sis use# in t9e mo#e* as provi#e# b- 66 an# is un#erstoo# to be ta:en from +=V8 an# +&V3 e** ana*-ses. ,or*e-+arsons ma:e no comment as to t9e re*iabi*it- of t9e pro#uce# ater ana*-sis or *i:e*i9oo# of t9e pro#uce# ater c9emistr- use# in t9is ana*-sis bein' appropriate at 66an# 66 over t9eir #esi'n *ife. T9e corrosion a**oances for t9e topsi#e pro#uction e@uipment is #escribe# in Tab*e " B3. Tab*e " B3 s9os t9e ca*cu*ate# corrosion a**oance it9 an# it9out t9e benefit of bufferin' from pro#uce# ater. Tab%e "&3 <0 Topsi#e 0ro#uction *+uipment Corrosion A%%o=ances *+uipment

Ca%cu%ate# !eta% oss an# Corrosion A%%o=ance 6mm8

+a'e 32

!o#e* a ,ater of Con#ensation On*-

!o#e* b ,ater of Con#ensation K +ro#uce# ,ater

Interna* !eta* (oss

Tota* CA

Interna* !eta* (oss

Tota* CA

+ro#uction )*o*ines B 66 B 66+

".1 .""

8.; .;

1.33 1.2

3.; 3.;

Test ea#er B66 66

".1 .""

8.; .;

1.33 1.2

3.; 3.;

.83 .18

.; .;

1.25 1.23

3.; 3.;

+ro#uction ea#er B66 B 66

T9e corrosion of t9e topsi#e e@uipment s9ou*# a*so account for e6terna* corrosion 9ere pipin' runnin' at an e*evate# temperature i** be prone to coatin' brea:#on an# 9ence e6posure of t9e 9ot stee* surface to a marine environment. Consi#erin' t9at bot966 an# S66 e**9ea# p*atforms are unmanne# it is consi#ere# t9at a 1."mm e6terna* corrosion a**oance be a##e# to t9e pro#uction pipin'. T9e tota* corrosion a**oance /CA for t9e f*o*ines an# 9ea#ers for t9e to corrosion mo#e* cases are presente# in Tab*e " B3. T9e corrosion a**oances for t9e pro#uction e6port pipe*ines on 66 an# 66 are #escribe# be*o in Tab*e " B. Tab%e "&

0ro#uction *(port 0ipe%ine Interna% Corrosion A%%o=ances 62 'ears8

0ipe%ine

In%et Accumu%ate# Corrosion 6mm8

Out%et Accumu%ate# Corrosion 6mm8

Corrosion A%%o=ance 6mm8

!o#e* a ,ater of Con#ensation On*66 +ro#uction %6port

."1

"."3

.;

66 +ro#uction %6port

.1

.28

.;

!o#e* b ,ater of Con#ensation K +ro#uce# ,ater 66 +ro#uction %6port

1.24

1."

3.;

66 +ro#uction %6port

1.23

1.5;

3.;

Refer to Section 4.2.3 for recommen#ation of a*ternative materia*s.

T9e corrosion rate for t9e e6port pipe*ines from 66 an# 66 to 66 are ver- sensitive to t9e p bufferin' effect of t9e pro#uce# ater. >ariabi*it- in t9e bicarbonate concentration in t9e pro#uce# ater ana*-sis /as provi#e# b- %+I( as foun# to 9ave *itt*e effect on t9e corrosion rate an# t9is is #emonstrate# in Tab*e " B".

+a'e 33

,9at is un:non about t9e pro#uce# ater c9emistr- is 9o muc9  2S an# CO2 i** react it9 t9e ater #urin' t9e *on' e6posure time a*on' t9e pipe*ines *en't9. T9e t-pica* pro#uce# ater c9emistrprovi#e# in Section 3.3.3 is a separator c9emistr- an# as not e6pose# to a *on' #uration of mi6in' it9 a CO2 /1;t an# 2S /1;;ppm *a#en pro#uction *i@ui# 9ic9 ma- become more aci#ic an# 9ence more corrosive over time. It is a*so important to note t9at t9e NORSOG !"; corrosion mo#e*7 as is t9e case for most CO 2 corrosion mo#e*s7 #oes not account for t9e effect of  2S on t9e overa** corrosion rate. T9e corrosion rate inc*u#in'  2S varies t9rou'9 #ifferent temperature Jones7 9ic9 is main*- because t9e #ifferent sca*es t9at form on t9e stee* 9ave #ifferent structures an# 9ence 9ave varie# porosit- an# a#9esion properties. A** of 9ic9 effects t9e passivation of t9e stee* an# 9et9er it corro#es or not. Tab%e "&" Sensitivit' Ana%'sis of 0ro#uce# ater C)emistr' 6(( *(port 0ipe%ine8 ;icarbonate eve%

Accumu%ate# Corrosion Dama-e 62 'ears8 659 in)ibitor avai%abi%it' an# 55 in)ibitor efficienc'8

1;; C9emistr- /151 m'*

1.24mm

5; C9emistr- /1"22m'*

1.24mm

8" C9emistr- /124m'*

1.25mm

". 2

C orrosion In)i bi tio n 0) i% os op) '

". 2. 1

, enera%

Corrosion in9ibitor i** be assesse# as t9e primar- means of corrosion mana'ement in et process streams an# pipe*ines to a**o t9e use of carbon stee* it9 an acceptab*e corrosion a**oance7 provi#e# t9e c9emica*s use# an# t9e met9o# of injection can effective*- an# re*iab*- contro* t9e corrosion rate. T9e in9ibitor effectiveness comprises t9e efficienc- of t9e c9emica* in t9e process /9o muc9 it re#uces t9e native unin9ibite# corrosion rate 9en #ose# proper*-7 an# t9e re*iabi*it- of t9e injection process /9o often in9ibitor is actua**- injecte# an# avai*ab*e to in9ibit corrosion in t9e process. )or t9is project7 t9e va*ues for t9e in9ibite# corrosion rate an# in9ibitor avai*abi*it- to be use# for materia* se*ection an# corrosion a**oance #etermination purposes for t9e 66 /or 66 to 66 subsea pipe*ines i** be in accor#ance it9 t9e fo**oin' Tab*e " B from Rippon Ref  Tab%e "&4 In)ibite# Corrosion Rates an# In)ibitor Avai%abi%it' Ref 4E Temperature Ran-e 6 C8

In)ibite# Corrosion Rate 6mm'8

Specifie# In)ibitor Injection Avai%abi%it' 68

!anne# +*atform

Unmanne# +*atform

Up to 8;°C

;.;"

55

5"

P 8;°C an# ≤12;°C

;.1

55

5"

P 12;°C an# ≤1";°C

;.2

55

5"

Above 1";°C

In9ibition not recommen#e# it9out specific testin'

)or unmanne# faci*ities it9 c9emica* stora'e an# injection faci*ities *ocate# on t9e p*atform Rippon recommen#s a 5" mec9anica* avai*abi*it- of t9e c9emica* injection s-stem. oever7 in t9is case it

+a'e 3

is t9e current #esi'n premise to 9ave t9e c9emica* injection pumps an# c9emica* stora'e *ocate# on t9e 66 p*atform7 9ic9 is manne#. )or t9is scenario it is consi#ere# 'oo# practice to assume a corrosion in9ibitor avai*abi*it- of 54. +rojects suc9 as =+ =i**iton !inerva /Austra*ia7 Ota- =asin7 Ne6us %ner'- (on'tom /Austra*ia7 =ass Strait an# Santos Casino /Austra*ia7 Ota- =asin are remote subsea #eve*opments contro**e# b- ons9ore faci*ities /up to ;:m aa- an# t9ese projects a** assume 55 c9emica* injection avai*abi*it-. A fie*# arran'ement simi*ar to 66 is use# in t9e Gerr !c&ee C9ina +etro*eum Deve*opment in =o9ai =a-7 Nort9ern C9ina. G!&C+ 9ave unmanne# e**9ea# p*atforms t9at are supp*ie# it9 in9ibitor an# ot9er c9emica*s from remote manne# pro#uction p*atforms an# )+SO. G!&C+ operate usin' 54 corrosion in9ibitor avai*abi*it- for t9eir unmanne# e**9ea# p*atforms. )or t9e topsi#e pro#uction an# test 9ea#ers t9rou'9 to t9e e6port pipe*ine t9e corrosion in9ibitor i** be supp*ie# t9rou'9 mu*tip*e injection points /i.e. one per f*o*ine7 upstream of t9e c9o:e va*ve an# t9erefore a comp*ete unavai*abi*it- of in9ibitor ou*# re@uire mu*tip*e fai*ures of t9e injection points. )or t9e in#ivi#ua* f*o*ines7 9en t9e injection s-stem fai*s7 t9e f*o*ine i** 'o it9out corrosion in9ibition an# t9erefore t9e 54 avai*abi*it- ma- not be obtainab*e an# 9ence eit9er a CRA materia* or a *ar'e corrosion a**oance /Pmm is to be consi#ere# for t9e f*o*ines. A *ist of possib*e unin9ibite# events is provi#e# in Appen#i6 3 it9 su''este# contro* options. +ipe*ines operate un#er fair*- e** #efine# f*o re'imes it9 constant pipe #iameterH 9ereas topsi#e pro#uction an# process p*ant s-stems operate it9 variab*e pipe #iameters7 f*o re'imes an# f*ui# ve*ocities. T9e- can a*so possess areas of 9i'9 f*o7 f*o #isturbances7 impin'ement7 #ea# *e's7 crevices7 etc.7 t9at can re#uce t9e performance of t9e corrosion in9ibitor. Conse@uent*-7 an in9ibitor overa** in9ibitor effectiveness /i.e. ta:in' account of t9e in9ibitor efficienc- an# in9ibitor avai*abi*it- *imit of 5" is recommen#e# for topsi#e pipeor:. As part of t9e materia*s se*ection process7 t9e in9ibitor effectiveness re@uire# to a**o a #esire# corrosion a**oance to be ac9ieve# for t9e #esi'n *ife 9as been ca*cu*ate# for eac9 process stream. S9ou*# t9e in9ibitor fai* to ac9ieve t9e performance stan#ar# assume# in t9e materia*s se*ection7 e6cessive corrosion maoccur 'ivin' rise to t9e ris: of premature fai*ure. It is critica* t9at t9e tar'et in9ibitor avai*abi*it- an# effectiveness is ac9ieve#7 b- •

%nsurin' t9at t9e in9ibitor c9emica* specifie# is ab*e to ac9ieve t9e specifie# in9ibite# corrosion rate /e.'. ≤;.;"mm-r for TM8;QC irrespective of t9e corrosivit- of t9e environment /see Section ".1.

•

%nsurin' t9at t9e #ose of c9emica* is sufficient to be ab*e to ac9ieve t9is *eve* of protection t9rou'9out t9e s-stem to be protecte#7 an# t9at faci*ities to c9ec: t9is effectiveness /corrosion monitorin' an# samp*e points are provi#e# at appropriate positions in t9e process.

•

%nsurin' t9at t9e in9ibitor is injecte# in a manner t9at t9e fu** performance efficienc- of t9e c9emica* can be ac9ieve# t9rou'9out t9e s-stem7 b- t9e appropriate *ocation of injection points7 an# t9e specification of t9e proper injection a66ratus /i.e. @ui**satomiser.

•

%nsurin' t9at t9e c9emica* injection s-stem is sufficient*- re*iab*e to provi#e c9emica* injection for a #efine# percenta'e of t9e #esi'n *ife /e.'. at *east 54 of t9e time for an unmanne# p*atform7 usua**- b- t9e use of motor /not air'as #riven pumps7 provision of a*arms or in#icators 9en injection stops7 re'u*ar operator survei**ance7 etc. /see Section ".2.

•

%nsurin' t9at t9e onsite faci*ities are e@uippe# it9 sufficient c9emica* stora'e capacit- to provi#e continuous supp*- of c9emica* for t9e ma6imum #uration beteen supp*ies7 ta:in' into account suc9 factors as storms preventin' off*oa#in'.

+a'e 3"

)ai*ure to ensure t9e tar'et in9ibitor effectiveness is met i** re#uce t9e *ife of t9e s-stem7 potentia**be*o t9e re@uire# 2;B-ear #esi'n *ife.

" .2 .2

C )e mi ca % 0 er fo rm an ce

T9e c9emica*s current*- use# in t9e 66 an# 66fie*#s are as fo**os •

Corrosion In9ibitor C9ampion Tec9no*o'ies Crono6 !(B"5H

•

Sca*e In9ibitor C9ampion Tec9no*o'ies &r-pton ITB2.

Detai*s of t9ese c9emica*s are provi#e# in Appen#i6 . T9e c9emica*[s abi*it- to ac9ieve t9e tar'et in9ibite# corrosion rate must be proven for t9e 66 an# 66 con#itions prior to #ep*o-ment7 particu*ar*- in 9i'9*- corrosive s-stems7 9ere t9e conse@uences of not meetin' t9e specifie# in9ibition tar'et cou*# be ver- 9i'9.

" . 2. 3

C ) em ic a% I nj e ct i on S' st e m D es i -n

T9e #etai*e# #esi'n of t9e s-stem /i.e. p*acement of injection points7 #esi'n of injection @ui**s7 #esi'n of c9emica* supp*- s-stems7 avai*abi*it- of pumps7 potentia* for b*oc:a'es7 provision of a*arms an# bac:ups7 @ua*it- of e@uipment purc9ase# i** #ictate t9e base mec9anica* re*iabi*it- of t9e s-stem7 an# so 9ave a stron' effect on t9e overa** effectiveness of t9e in9ibitor treatment over t9e *ife of t9e fie*#. T9e In9ibitor S-stem Desi'n Criteria 'iven in Tab*e " B8 must be incorporate# into t9e overa** faci*it#esi'n to meet t9e re@uire# tar'et s-stem avai*abi*it- /see Section 1; for t9e remote7 unmanne# 66an# 66 e**9ea# p*atform. )or comparison7 t9e tab*e provi#es t9e in9ibitor s-stem #esi'n criteria t9at ou*# be re@uire# to ac9ieve a 5"7 54 an# 55 avai*abi*it- tar'ets. Tab%e "&? Criteria for In)ibitor S'stem Desi-n to !eet a Specifie# S'stem Avai%abi%it' Item

In9ibitor #emonstrate# as suitab*e for t9e app*ication In9ibitor injection pumps =ac: up pumps

In)ibitor Avai%abi%it' 5"

59

55







Stan#ar#

i'9 re*iabi*it-

i'9 re*iabi*it-



Automate# +referab*e for Remote Sites



Automate#

C9ec: t9at pump is operatin'

Dai*- !anua* C9ec:

Automate# A*arm for Remote Sites

Automate# A*arm

+ump p*anne# maintenance

Annua*

Annua*

Annua*

Dai*- !anua* C9ec:

Automate# A*arm for Remote Sites

Automate# A*arm

In9ibitor tan: *eve*s

+a'e 3

Item

In)ibitor Avai%abi%it' 5"

59

55

!ont9*-

,ee:*-

,ee:*-

?uarter*- manua* c9ec: on pump injection rate







No f*o a*arm /Jero #ifferentia* pressure across a critica* component7 or in *ine f*o meters







(i@ui# samp*es for ana*-sis of resi#ua* in9ibitor *eve*s an# ater c9emistr-

!ont9*-

!ont9*-

!ont9*-

Corrosion monitorin' s-stem response time.

Response time suc9 t9at tota* number of events 6 time to respon# is M14 #a-s

Response time suc9 t9at tota* number of events 6 time to respon# is M4 #a-s

Response time suc9 t9at tota* number of events 6 time to respon# is M #a-s

T-pica* c9oices for corrosion monitorin' e@uipment an# s-stem response times

At *east annua* manua* corrosion measurements

On *ine %R probesH response time 1B #a-s an# #ai*- in9ibitor injection concentration

On *ine %R probesH response time 1B #a-s an# #ai*- in9ibitor injection concentration

Desirab*e

Re@uire#

Re@uire#







A**oe# #a-s in9ibitor s-stem #ontime per -ear

14

4



S9utBin if in9ibition s-stem 'oes #on for 'reater t9an a #efine# perio# of time

%ffective*- never an issue

+ossib*- /#epen#in' on corrosivit- of s-stem

+ossib*- /Note +robab*- for 9i'9 corrosivit- s-stems

C9ec: for orstBcase corrosion in s9ut#on con#itions

%ffective*- never an issue

+ossib*- /#epen#in' on corrosivit- of s-stem

+ossib*- /Note +robab*- for 9i'9 corrosivit- s-stems







Report on in9ibitor use# /or report on comp*iance it9 :eperformance in#icators to responsib*e corrosion en'ineer

Compre9ensive revie of unin9ibite# events +ersistenc- ta:en into account

I#entif- Operations Tec9nician it9 responsibi*it- for t9e in9ibition injection s-stem

for Remote Sites

+a'e 38

Item

In)ibitor Avai%abi%it'

Corrosion %n'ineerin' Invo*vement Ge- +erformance In#icators set for Operations Tec9nicians an# Corrosion %n'ineers

5"

59

55

!ont9*- Revie

)ortni'9t*- Revie

,ee:*- Revie







As in#icate# in Section ".17 carbon stee* is viab*e for a 2; -ear #esi'n *ife. If carbon stee* f*o*ines are use# on 66 an# 667 corrosion in9ibitor ou*# nee# to be injecte# upstream of t9e c9o:e on eac9 e**9ea#7 9ic9 ou*# provi#e t9orou'9 mi6in' an# #istribution of t9e in9ibitor into t9e f*ui#s. If t9e corrosion in9ibitor is prone to c*o''in' t9e injection *ines an# fittin's t9en #i*ution of t9e in9ibitor in #iese* oi* to improve t9e in9ibitors viscosit- s9ou*# be consi#ere#. T9e #i*ution of t9e in9ibitor an# t9e effect on its effective injection rate s9ou*# be ca*cu*ate# in conjunction it9 t9e fie*#[s c9emica* supp*ier7 C9ampion Tec9no*o'ies. If t9e in9ibitor is #i*ute# it9 #iese* t9en a *ar'er vo*ume of f*ui# i** 9ave to be pumpe# an# 9ence t9e injection pump siJes s9ou*# be increase# accor#in'*-. If CRA f*o*ines are use# an# corrosion in9ibitor is re@uire# for protection of t9e 66to 66 pipe*ine an# 66B66 pipe*ine7 an atomisin' injection @ui** s9ou*# be use# #onstream of t9e pro#uction f*o*ine to ensure t9at t9e in9ibitor is effective*- #istribute# in t9e 'as p9ase. T9is s-stem can be #esi'ne# it9 automatic bac:Bup pumps to improve t9e s-stem re*iabi*it-7 as oppose# to t9e use of mu*tip*e injection pumps for eac9 e**9ea#. +rovision i** nee# to be ma#e for corrosion in9ibitor injection on 66 for protection of t9e #e9-#rate# 'as*ift pipe*ine in t9e event of #e9-#ration upsets. T9is s9ou*# be coor#inate# it9 #eaterin' pi's to remove ater t9at ma- 9ave sett*e# at *o spots in t9e pipe*ine.

" .2 .

O pe ra ti on an # R e% ia bi %i t'

T9e @ua*it- of operation of t9e c9emica* injection s-stem is critica* to t9e effectiveness of t9e in9ibitor treatment an# t9erefore to t9e re*iabi*it- of carbon stee* s-stems. )actors inc*u#e t9e @ua*it- an# consistenc- of c9emica* supp*-7 re'u*ar operator c9ec:s  contro* room survei**ance7 pump an# injector maintenance7 injection a#justment an# performance verification.

+a'e 34

4.

0I,,IN, R*FUIR*!*N TS

4.1

Operationa% 0i--in-

+ipe*ine pi''in' can 9ave a major impact on t9e operationa* an# tec9nica* inte'rit- of a pipe*ine. +i''in' can 9ave a number of operationa* purposes •

C*eanin' of t9e pipe*ine prior to an inte**i'ent pi' inspectionH

•

Inte**i'ent pi' runsH

•

C*eanin' to prevent f*o restrictions /a67 asp9a*tene an# sca*e bui*#BupH

•

(i@ui#s inventor- mana'ementH

•

Interna* corrosion contro*H an#

•

In9ibitor #istribution.

T9e subsea pro#uction pipe*ines i** 9ave pi' *aunc9ers an# receivers fitte# to enab*e operationa* pi''in'. T9e current #esi'n basis #oes not provi#e for permanent 'as *ift *aunc9ers an# receiversH t9is arran'ement is satisfactor- if corrosion in9ibition is continuous*- injecte# into t9e 'as *ift pipe*ines. If t9e corrosion in9ibition is to be on*- injecte# 9en t9e 'as *ift 'as 'oes off #e point /et 'as operation t9en it is recommen#e# t9at permanent *aunc9ers an# receivers are insta**e# to permit perio#ic seepin' of free ater from t9e 'as *ift pipe*ine an# runnin' batc9 corrosion in9ibitor. +i''in' for corrosion contro* mabe re@uire# for a number of reasons •

)or ne an# e6istin' *ines7 t9e *ines s9ou*# be c*eane# an# batc9 pi''e# it9 a fi*min' in9ibitor prior to commencement of continuous in9ibitor injection to ensure access of t9e in9ibitor to t9e pipe a** to ma6imise in9ibitor effectiveness from start up. T9e continuous in9ibitor ta:es a finite time to trave* #on t9e pipe*ine from startBup an# t9e batc9 in9ibitor i** prevent ancorrosion from occurrin'.

•

+i''in' s9ou*# be performe# #urin' commissionin' in or#er to remove an- mi** sca*e an# *oose surface corrosion from t9e pipe a**s. T9is i** 9e*p to improve corrosion in9ibitor efficienc- bre#ucin' t9e surface area avai*ab*e in t9e pipe 9ere corrosion in9ibitor can be a#sorbe# an# remove# from t9e corrosion in9ibition of t9e stee*.

•

Distribution of in9ibitor containin' bottom f*ui#s to t9e top of t9e *ine /TO( 9ere TO( corrosion is a concern.

•

Remova* of sta'nant ater poo*s in stratifie# f*o re'imes7 9ere continuous*- injecte# in9ibitor mabe *ess effective an#or re@uire 9i'9er #ose rates t9an more turbu*ent s-stems.

•

Remova* of san# an# ot9er so*i#s t9at ma- a#verse*- affect t9e performance of t9e in9ibitor.

Scraper pi's are 'enera**- sent t9rou'9 t9e pipe*ine a9ea# of inte**i'ent pi''in' operation to ensure t9at t9e inte**i'ent pi' #oes not 'et stuc: in t9e pipe*ine. T9e #ebris co**ecte# b- t9e scraper pi' i** be #eposite# in t9e pi' receiver. Samp*es of t9is materia* s9ou*# be ta:en an# ana*-se#.

+a'e 35

4. 2

I nte %%i -ent I nspe ct ion 0i --i n-

4. 2. 1

, enera%

Deterioration of t9e pipe*ine is primari*- a resu*t of corrosion b- a''ressive contaminants. Contro* of t9e #eterioration i** be t9rou'9 c9emica* treatment. To ensure t9e inte'rit- of t9e pipe*ine7 it mabe necessar- to un#erta:e a number of maintenance an# inspection pi''in' routines t9rou'9out t9e *ife of t9e pipe*ine.

4 . 2. 2

I n te %% i -e nt 0 i -- i n- R e+ u ir em en t s

Un#er a safet- case re'ime7 t9ere are no #efinitive inspection perio#s for inte**i'ent pi''in'. T9e re@uirements for inte**i'ent pi''in' are #etermine# t9rou'9 a consu*tative process 9ereb- t9e re'u*ator an# pipe*ine *icense 9o*#er set an a'ree# inspection perio#7 base# on t9e fo**oin' parameters •

+re#icte# corrosion rateH

•

Corrosion mana'ement pro'ramH

•

Corrosion monitorin' pro'ramH

•

Operatin' 9istor-H an#

•

Operator e6perience.

T9e base inte**i'ent pi''in' fre@uenc- i** be base# on a set interva* /t-pica**- " -ears7 minimum7 it9 a##itiona* I+ runs performe# as nee#e# base# upon t9e above parameters.

4 .2. 3

0 i- -i n- / re+ ue nc '

T9ere are to approac9es to #eterminin' t9e re@uirements for inte**i'ent pi''in'. To 'et t9e ma6imum benefit from performin' inte**i'ent pi''in' inspections7 t9e inspection too* s9a** on*- be run 9en it is e6pecte# t9at anoma*ies are present at *eve*s #etectab*e b- t9e inspection too*. )or t-pica* 9i'9Breso*ution ma'netic f*u6 *ea:a'e too*s7 t9is #etection *imit is 'enera**- 1; of a** t9ic:ness or 1 mm7 9ic9ever is 'reatest. T9erefore7 in #eterminin' t9e pi''in' fre@uenc-7 t9e e6pecte# corrosion rate s9ou*# be use# to ensure t9at inte**i'ent pi''in' is not performe# unnecessari*-. T9e corrosion rate use# in #eterminin' t9e fre@uenc- of pi''in' is t-pica**- t9e unin9ibite# corrosion rate. oever7 t9e pipe*ine s9a** be #esi'ne# so t9at t9e corrosion in9ibitor is injecte# continuous*- an# s9ou*# approac9 1;; avai*abi*it-. If t9is corrosion mana'ement p9i*osop9- is confirme# b- inB*ine corrosion monitorin' #evices /e.'. t9e probes or sensor spoo*s7 t9en potentia**- re'u*ar inte**i'ent pi''in' i** not be re@uire# for t9e *ife of t9e pipe*ine base# on t9e #etection *imit an# a ma6imum in9ibite# corrosion rate. &enera**-7 t9e *oca* re'u*ator- bo#- insists on inte**i'ent pi''in' of et CO 2 pipe*ines on a re'u*ar fre@uenc-. T9is fre@uenc- is t-pica**- ever- 3 to " -ears7 #epen#in' on t9e 9istor- of t9e pipe*ine7 t9e e6perience of t9e operator7 an# t9e corrosion monitorin' an# miti'ation pro'rams in p*ace.

+a'e ;

?.

S 0 * C I / I C !A ! AT * R I A A A0 A0 0  I C AT I O N S

?. 1

U se se of o f Co C o r r o s io io n Re R e s i st st an an t A% A% %o %o ' s

? . 1. 1. 1

, r a #e #e 3 3   3 3   A us u s t en e n i t i c S t ai a i n % es e s s S t ee ee % s

&ra#e 3;3;( 3;3;( stain*ess stee*s s9a** not be use# in critica* service for pipeor:7 tubin'7 vesse*s7 e@uipment7 bo*tin' or fi6in's e6pose# to marine or sa*tB*a#en air7 or aerate# c9*ori#eBcontainin' ater7 #ue to t9e ris: of pittin'7 crevice corrosion or c9*ori#eBin#uce# stress corrosion crac:in' at antemperature above ambient. Ro'ue 3; stain*ess stee* materia*s re'u*ar*- turn up on offs9ore faci*ities #ue to its use in ven#or stan#ar# va*ve bo*tin'. A** va*ves use# offs9ore in pressure containin' service s9ou*# be specifie# as No 3; Stain*ess Stee* /=4 materia*s permitte#0.

? . 1. 1. 2

, r a #e #e 31 31 4  31 31 4  A us u s t en e n i t i c S t ai a i n % es e s s S t ee ee % s

&ra#e 3131( s9a** not be use# in critica* service for an- pipin' or for t9e e6terna*s of e@uipment above a temperature of ;QC #ue to t9e ris: of e6terna* c9*ori#eBin#uce# pittin' an# stress corrosion crac:in' /CSCC. Consi#eration s9ou*# be 'iven to t9e use of 31( c*a# carbon stee* rat9er t9an so*i# 31( vesse*s /particu*ar*- in a marine environment environment un*ess c*a##in' is s9on to be si'nificant*- *ess economic. &ra#e 31( mabe use# as a c*a##in' materia* or for vesse* interna*s in seet /i.e. on*- CO 2 9-#rocarbon service provi#in' o6-'en an#or  2S are not present. =efore so*i# materia* is use# /particu*ar*- in a marine environment7 environment7 consi#eration s9a** be 'iven to t9e possibi*it- of an increase in t9e e6terna* s:in temperature temperature above ; °C #ue to so*ar ra#iation or 9eat from surroun#in' e@uipment7 9ic9 ma- a*so cause c9*ori#e concentration #ue to surface evaporation. evaporation. In t9ese con#itions7 con#itions7 31( is not not acceptab*e for critica* service. service. Consi#eration Consi#eration can be 'iven to t9e use of factor- app*ie# t9erma* spra- a*uminium /TSA as an e6terna* coatin' to act as a surface barrier an# s9ift t9e stain*ess stee* potentia* out of t 9e SSC re'ime7 but t9e effectiveness of suc9 a coatin' over a 2; -ear #esi'n *ife s9a** be consi#ere# consi#ere# for critica* service. Consi#eration Consi#eration s9a** a*so be 'iven to t9e practica*it- of site app*ication of TSA at fie*# joints7 since t9is 9as been s9on to be prob*ematica* an# to a#verse*- affect t9e performance of t9e coatin'. In t9e absence of CO 2 an# 2S7 &ra#e 31( stain*ess stee* s9a** not be use# in critica* service for process or uti*it- streams containin' o6-'en above ; °C if t9e c9*ori#e content is above 3;; ppm. T9e materia* s9a** not be use# for an- 9eat transfer surface app*ications in suc9 streams at antemperature or c9*ori#e content #ue to t9e ris: of c9*ori#e concentration effects. &ra#e 3131( stain*ess stee* pipin' for pressure retainin' purposes mabe use# above ; °C if it is not insu*ate# an# is *ocate# in#oors un#er >AC contro*. )or unBinsu*ate# instrument tubin' #onstream of a s9utBoff va*ve7 norma**- no e6tra precaution is re@uire# provi#in' t9ere is no f*o in t9e instrument pipin' an# t9e process me#ia temperature is *ess t9an 4" °C. !ateria* *imits an# manufacturin' contro*s for 3131( stain*ess stee* are summarise# in Tab*e Tab*e 8 B4. B4 .

+a'e 1

Tab%e ?&9  !ateria% imits an# !anufacturin- Contro%s for 314314 Stain%ess Stee% T'pe T'pe of Service 0ro#uce# /%ui#s

Oi% 6no =ater8

et ,as

Dr' ,as

0ro#uce# ater

Temperature imits 6GC8

!in Service Temp ,it9out Impact Testin' Testin'

A** t9ic:nesses

B1;"

B1;"

B1;"

B1;"

B1;"

!in Service Temp ,it9 Impact Testin'

A** t9ic:nesses

B15

B15

B15

B15

B15

!a6 Se Servi rvice Temp B Un Uncoat oate#

Atmo Atmos sp9er p9eriic !arine /(o aJar#

;

;

;

;

;

";

";

";

8;

";

2."

2."

2."

2."

2."

$%S

$%S

$%S

$%S

$%S

/%o= Be%ocit' imits it)out San# 6ms8

)*o >e*ocit- (imit !anufacturin- imits : Contro%s

Compositiona* Constraints

!in !o*-b#enum for t9in a** tubin'

So*ution Annea* E ?uenc9 for +ipe E )ittin's

? . 1. 1. 3

4 !o ! o S u pe p e r& r & Au A u s te te ni n i t ic i c 2 " "  S !O ! O 6 U NS NS S 31 3 1 2 " " 8

!o superBaustenitic superBaustenitic stain*ess stee* suc9 as 2" S!O /UNS S312" can be re'ar#e# as resistant to CO2 corrosion but s9a** be *imite# to an operatin' temperature of 12;QC in an e6terna* sa*iferous /i.e. sa*t *a#en air environment. T9e minimum #esi'n temperature s9a** be B1;1QC it9out impact testin' or B15QC it9 impact testin'.

? .1 . 1 . .

D up u p %e % e ( S ta t a in i n %e % e ss ss S te t e e% e%

Dup*e6 stain*ess can be consi#ere# resistant to e6terna* c9*ori#e in#uce# stress corrosion crac:in' /CISCC up to temperatures of 1;; °C for 22Cr #up*e6 an# 11; °C for 2"Cr super #up*e6 stain*ess stee*s. Crac:in' above t9ese temperatures is on*- *i:e*- if t9e vesse* or pipeor: is *a''e# an# sa*ineseaater 'ets trappe# un#er t9e *a''in' or is #rippe# continuous*- onto 9ot pipeor:. Nevert9e*ess7 as a precaution7 it is recommen#e# to TSA coat #up*e6 stain*ess stee* e@uipment operatin' above t9ese temperatures in an offs9ore marine environment. Dup*e6 stain*ess stee*s can be consi#ere# to be resistant to ei'9t *oss corrosion an# pittin' corrosion in seet 9-#rocarbon pro#uction environments environments /i.e. CO 2 on*- at CO2 partia* pressures up to 1;; bar7 temperatures up to 2;; °C an# up to 2;7;;; ppm /2;;'* NaC*.

+a'e 2

!ateria* *imits an# manufacturin' contro*s for 22Cr #up*e6 stain*ess stee* are summarise# in Tab*e 8 B5 be*o. T-pica**- t9rou'9out t9is #ocument 9en 22Cr is reference#7 t9e basic specification UNS S314;3 is inferre#. oever7 9ere a 9i'9er pittin' ris: is perceive# t9en t9e 9i'9er specification 22Cr7 UNS S322;"7 i** be specifie# as it contains a 'uarantee# minimum mo*-b#enum content of 2."7 9ic9 ensures a 'reater pittin' resistance t9an t9e base 'ra#e #up*e6 stain*ess stee*. Tab%e ?&5  !ateria% imits an# !anufacturin- Contro%s for 22Cr Dup%e( Stain%ess Stee% T'pe of Service 0ro#uce# /%ui#s

Oi% 6no =ater8

et ,as

Dr' ,as

0ro#uce# ater



Z mm

B";

B";

B";

B";

B";


P mm

;

;

;

;

;


P mm

B";

B";

B";

B";

B";

!a6 Service Temp B Uncoate#

Atmosp9eric !arine

1;;

1;;

1;;

1;;

1;;

!a6 Temp Due to %mbritt*ement

AS!% =31.3 Tab*e AB1

31"

31"

31"

31"

31"

";

";

";

8;

";

3"  "

3"  "

3"  "

3"  "

3"  "

33

33

33

33

33

!inimum Nitro'en Content /

;.1"

;.1"

;.1"

;.1"

;.1"

So*ution Annea* E @uenc9 for +ipe E )ittin's

$%S

$%S

$%S

$%S

$%S



!eta**ur'ica* Constraints

)errite Content

!inimum +R%n

!ateria* *imits an# manufacturin' contro*s for 2"Cr super #up*e6 stain*ess stee* are summarise# in Tab*e Tab*e 8 B1; be*o.

+a'e 3

Tab%e ?&1  !ateria% imits an# !anufacturin- Contro%s for 2"Cr Super Dup%e( Stain%ess Stee% T'pe of Service 0ro#uce# /%ui#s

Oi% 6no =ater8

et ,as

Dr' ,as

0ro#uce# ater


!in Service Temp ,it9out Impact Testin'

Z mm

B";

B";

B";

B";

B";

!in Service Temp ,it9out Impact Testin'

P mm

;

;

;

;

;


P mm

B";

B";

B";

B";

B";

!a6 Service Temp B Uncoate#

Atmosp9eric !arine

12;

12;

12;

12;

12;

!a6 Temp Due to %mbritt*ement

AS!% =31.3 Tab*e AB1

31"

31"

31"

31"

31"

";

";

";

8;

";

3"  "

3"  "

3"  "

3"  "

3"  "

;

;

;

;

;

$%S

$%S

$%S

$%S

$%S



!eta**ur'ica* Constraints

)errite Content

!inimum +R%n So*ution Annea* E @uenc9 for +ipe E )ittin's

? . 1. "

S e% e ct i on o f CR A f o r 0 i pe a n# Be ss e% s

T9e use of CRA c*a# carbon stee* is becomin' increasin' #ifficu*t #ue to t9e 9i'9 or*#i#e #eman# for c*a# stee* an# t9ere bein' on*- B" manufactures in t9e or*# to provi#e t9e materia*s. It is for t9is reason t9at c*a# pipe an# vesse*s are not consi#ere# as part of t9is materia* stu#-.

? .2

U se o f , %a ss Re in fo rc e# 0 %a st ic 6 ,R 08

?. 2. 1

0i pi n- S 'st ems

T9e properties an# performance c9aracteristics of '*assBreinforce# p*astic /&R+ are #epen#ent on t9e resin use# for t9e composite matri6 an# t9e met9o# of manufacture. Suc9 factors s9a** be ta:en into account 9en se*ectin' a particu*ar pro#uct for a service app*ication. &R+ pipe mabe consi#ere# for open #rains7 pro#uce# ater pipin'7 injection *ines7 potab*e ater7 s-stems7 sanitar- s-stems an# #rain *ines subject to confirmation of t9e suitabi*it- of t9e resin t-pe for

+a'e 

t9e inten#e# service an# t9e pressure an# temperature ratin' for t9e pipe. %6amp*es of pressure ratin's an# resins use# in &R+ pipe from various manufacturers are s9o in Tab*e 8 B11 Temperature ratin's are usua**- of t9e or#er of 5;QC for epo6- base# s-stems7 but can be up to ]12;QC for po*-si*o6aneBp9eno*ic base# s-stems. It s9ou*# be emp9asise# t9at #esi'n7 fabrication an# insta**ation of &R+ s-stems7 inc*u#in' pipe supports7 joinin' s-stems an# e6pansion be**os7 are specia*ise# processes an# re@uire e6perience# personne* to ensure 'oo# @ua*it- an# performance. It is e6treme*- important t9at &R+ pipe be insta**e# b- bon#ers an# inspectors 9o 9ave been traine# an# certifie# to a specification approve# b- t9e oner. %n'ineerin' ana*-sis of &R+ pipin' s-stems is critica* to t9e prevention of premature fai*ures #ue to ina#e@uate support7 improper *ocation of supports7 ater 9ammer7 etc. ISO 152 /+arts 1 to  is no reco'nise# as t9e In#ustr- Stan#ar# for t9e #esi'n7 purc9ase7 manufacturin'7 @ua*ification testin'7 9an#*in'7 stora'e7 insta**ation7 commissionin' an# operation of &R+ pipin' s-stems in t9e petroc9emica* an# natura* 'as in#ustries. It provi#es terms an# #efinitions7 #escribes t9e p9i*osop9an# provi#es 'ui#ance on t9e ran'e of suitab*e app*ications7 an# #efines *imitations to t9e materia*s of construction for t9e specification7 manufacture7 testin' an# insta**ation of '*assBreinforce# p*astic /&R+ pipin' insta**ations. Its primar- focus is associate# it9 offs9ore app*ications on bot9 fi6e# an# f*oatin' topsi#es faci*ities for oi* an# 'as in#ustr- pro#uction an# processin'7 but ma- a*so be use# as 'ui#ance for t9e specification7 testin' an# insta**ation of &R+ s-stems in simi*ar ons9ore app*ications7 suc9 as fireater an# pro#uce# ater s-stems. Severe impact events can cause craJin' in t9e pipe a** an# t9erefore &R+ pipe s9ou*# be *ocate# to re#uce t9e occurrence of impact *oa#s 9erever possib*e7 or p9-sica**- protecte#. A*t9ou'9 in#ustr- stan#ar#s are avai*ab*e to 'overn t9e specification of &R+ pipin' s-stems7 &R+ pipe manufacturers i** provi#e s-stem en'ineerin' assistance7 supp*- materia*7 fabricate spoo*s7 provi#e onsite construction an# inspection7 an# con#uct proof tests. It is a#visab*e to use t9e services of t9e manufacturer as muc9 as possib*e.

? .2 .2

, R0 Tan @s an # Bes se %s

T-pica* app*ications for &R+ vesse*s inc*u#e ater fi*ters7 ater stora'e7 an# c9emica* stora'e. &R+ vesse*s can be use# to store 9-#rocarbons suc9 as #iese* fue*7 'aso*ine an# *ube oi* 9en approve# b- t9e 'overnin' re'u*ator- bo#-. >esse* manufacturers inc*u#e )orbes7 =a*mora*7 &ar*a-7 R(BIn#ustries7 Inc.7 %rs9i's7 Inc.7 an# (inco*n Composites. &enera**-7 t9e cost of &R+ is beteen t9at of carbon stee* an# stain*ess stee*. (oBpressure &R+ vesse*s an# tan:s are avai*ab*e for stora'e or process app*ications. (oB pressure vesse*s can be ver- *ar'e. +ressure ratin's 'o up to 1" psi' p*us t9e 9-#rostatic 9ea#. &overnin' stan#ar#s are AS!% RT+B1 an# =S 55. i'9Bpressure &R+ vesse*s are a*so avai*ab*e. i'9Bpressure vesse*s must be @ua*ifie# to AS!% Section . C*ass I vesse*s ma- 9ave pressure ratin's to 1";7 1";; or 3;;; psi'7 #epen#in' on t9e construction of t9e vesse*7 an# are @ua*ifie# b- test of a protot-pe to #estruction. C*ass II vesse*s ma9ave pressure ratin's ran'in' from 1" to 2;; psi #epen#in' on t9e #iameter an# t9e #esi'n met9o#. C*ass II vesse*s are @ua*ifie# b- nonB#estructive testin'. Desi'n an# fabrication of noJJ*es an# ot9er attac9ments it9 'oo# #urabi*it- is an en'ineerin' issue. &oo# procurement specifications are important. T9e fabrication @ua*it- contro* p*an an# user inspections are important consi#erations.

+a'e "

Tab%e ?&11 *(amp%es of 0ressure Ratin-s an# Resins Use# in ,R0 0ipe !anufacturer

0ro#uct

Series

T'pica% App%ication

Resin

0ressure Ratin60SI8

Ameron Internationa*

=on#stran#

2;;;!

&enera* App*ication E )ireater Rin' !ain

%po6-

2"; 22"

/10 to 10 /140 to ;0

2;;;!B)+

Dr- De*u'e +ipin'

%po6-

2";

/10 to 10

22;

+otab*e7 sa*tater7 brac:is9 ater an# seaater *ines

%po6-

25;

/20 to ;0

/20 //30 E 0 /[ to 40 /P120

)ire protection s-stems ,aste ater7 #raina'e an# sea'e s-stems

%DO Specia*it+*astics

)iberbon#

";;;!

Seaater C9*orination

>in-* %ster

"; 3"; 2"; 1";

8;;;!

Antistatic pipin' for Refine# +ro#ucts

%po6-

2"; /10 to 10 22" /140 to ;0

+SB(3

)ireater Rin' !ain

+o*-si*o6aneB+9eno*ic

2"; /20 to 0 22" /40 to 10

+SBF)

Dr- De*u'e +ipin'

+o*-si*o6aneB+9eno*ic

22"

2; >

&enera* App*ication

Iso +o*-ester

2; )R%

)ireater Rin' !ain

>in-* %ster

2;; /20 to 120 1"; /10 to 140 1;; /2;0 to 20

2; F)

Dr- De*u'e +ipin'

>in-* %ster

+a'e 

2;;

/10 to 120

/20 to 1;0

!anufacturer

0ro#uct

Series

T'pica% App%ication

Resin

0ressure Ratin60SI8

Smit9 )ibercast

&reen T9rea#

18"

&enera* App*ication

%po6-

18"

/20 to 20

2";

&enera* App*ication E )ireater Rin' !ain

%po6-

2";

/10 to 30

2"; B)

Dr- De*u'e +ipin'

%po6-

2";

/10 to 20

%ST 2;

&enera* App*ication

%po6-

2";

)uture +ipe

,aivistron'

+a'e 8

?. 3

Se %e ct ion of *% ast omeri c Sea% s

T9e fo**oin' materia*s ma- ta:e up pro#uct an# are t9erefore susceptib*e to e6p*osive #ecompression. T9e- s9ou*# not be use# for Ô[Brin's in 9-#rocarbon service •

>iton A

•

N=R /Nitri*e =uta#iene or Stan#ar# Rubbers

•

%*astBOB(ion 1;1 N=R /#oes not perform on *ar'er sections

!ateria*s it9 proven an# acceptab*e performance in 9-#rocarbon service inc*u#e •

Fames ,a*:er "45; />iton ^=[

•

Fames ,a*:er "454

•

Dot- 583;

•

&reene Tee# 42

Nitri*e /N=R an# 9-#ro'enate# nitri*e /N=R e*astomers are acceptab*e in nonB9-#rocarbon service it9 *o *eve*s of 2S if t9e temperature remains be*o ; °C. +T)% is a p*astic 9ic9 9as e6ce**ent c9emica* /an#  2S resistance7 but account s9ou*# be ta:en of t9e fact t9at p*astics re@uire #ifferent sea*in' confi'urations to e*astomers. In a** instances7 e*astomer se*ection s9ou*# ta:e into account t9e comp*ete operatin' con#itions to be encountere#7 especia**- t9e presence of amines from corrosion in9ibitors. Amines are curin' a'ents for =una an# Nitri*e rubbers causin' suc9 pro#ucts to overBa'e an# embritt*e. As a resu*t7 '*assBfi**e# +T)% sea*s are re@uire# for in9ibitor 9an#*in' e@uipment suc9 as pumps an# va*ves7 an# 'oo# amine resistance of T)%+ or ))G! e*astomers mabe re@uire# in critica* *ocations in 9-#rocarbon service 9ere 9i'9 aminein9ibitor concentrations cou*# be encountere#. >iton is rapi#*- #e'ra#e# b- met9ano* an# s9ou*# not be use# in an- s-stem t9at i** be e6pose# to met9ano*.

?.

;o%tin- !ateria%s

=o*tin' for carbon stee* pipin' is norma**- specifie# as *o a**o-7 @uenc9e# an# tempere# CrB!o stee*s to eit9er AST! A153 &r =8 an#or A32; &r (87 but a##itiona* protection is re@uire# for offs9ore marine app*ications. Carbon stee* bo*tin' is common*- ca#mium p*ate# an# +T)% coate#. oever7 t9e +T)% coatin' is on*- partia**- effective7 since #ama'e i** a*a-s occur #urin' insta**ation an# maintenance. T9ese coatin's usua**- comprise on*- 3;_m of +T)% an# 4_m of p*ate# ca#mium7 so *imite# protection is affor#e# 9ere t9e +T)% is #ama'e#. Some operators 9ave e6perience# corrosion of t9e bo*ts bt9e time of commissionin' or it9in 1B2 -ears7 *ea#in' to seiJin' of t9e nuts in t9e *on' term. T9e use of 9ot #ip spun 'a*vaniJe# stee* /S& bo*tin' to AST! A153 'ra#e =8 /nuts to AST! A15 'ra#e 2 s9ou*# a*so be consi#ere#7 since a number of operators 9ave 9a# poor performance it9 e*ectrop*ate#
+a'e 4

=S 1813 'ives t9e avera'e corrosion rate of Jinc in a 9i'9*- sa*ine atmosp9ere as B4 µm-r7 9ereas t9e minimum Jinc t9ic:ness 9en 'a*vaniJin' to =S 825 is 3 µm. T9is ou*# 'ive an avera'e *ife e6pectanc- of t9e 'a*vaniJe# *a-er of " an# 1; -ears before t9e 'a*vanic protection from t9e Jinc is *ost an# corrosion of t9e stee* substrate commences. In practice7 t9e 'a*vaniJin' t9ic:ness ten#s to be 'reater t9an 3 µm7 9ic9 provi#es *on'er coatin' *ife. Apart from corrosion7 t9e main issue t9at is fre@uent*- raise# it9 'a*vaniJe# stee* is *i@ui# meta* embritt*ement /(!% of a#jacent stain*ess stee*s. T9is is main*- an issue it9 austenitic stain*ess stee*s7 but can affect #up*e6 stain*ess7 9ic9 9ave an austeniteferrite matri6. It re@uires t9e simu*taneous presence of mo*ten Jinc7 9i'9 tensi*e stress an# temperatures over 8"; °C. oever7 in t9e event of a fire t9at cou*# *ea# to t9ese temperatures7 t9e mec9anica* properties of t9e stain*ess stee* i** 9ave been 'reat*- re#uce# before t9e critica* (!% temperature is reac9e#. T9e a##itiona* ris: of fai*ure #ue to (!% is t9erefore *o an# t9e use of 'a*vaniJe# bo*tin' on stain*ess stee* pipin' is re'ar#e# b- some operators /e.'. =+Amoco as acceptab*e. If 'a*vanise# stee* bo*tin' is use#7 bo*ts it9 a #iameter above 2"mm s9ou*# be impact teste# to t9e same re@uirements as for t9e stee* to be bo*te#. %6tra c*earance is re@uire# on t9e t9rea#s to a**o for t9e Jinc coatin' t9ic:ness an# it must be ensure# t9at 'a*vanise# nuts are not fitte# to +T)%e*ectrop*ate# bo*ts. =o*tin' for subsea service s9a** be in accor#ance it9 t9e re@uirements of DN> OS )1;1 Tab*e 8B2 as amen#e# in Fanuar- 2;;3.

+a'e 5

9.

! AT*R IA S S**CTI ON H  AN D  0 AT/ OR!

9 .1

 e% %) ea # * +u ip me nt 6 In c% u# in - C )o @e s a n# /% o= % in e Iso%ation Ba%ves8

,e**9ea# e@uipment is #efine# in t9e 66 Desi'n =asis Ref1 an# is a proprietar- supp*ie# item. T9e materia*s s9a** be se*ecte# in accor#ance it9 t9e re@uirements of A+I A. Accor#in' to A+I A for t9e con#itions prescribe# for 66 an# 66 t9e A+I !ateria* C*ass i** be ))07 9ic9 is mo#erate*corrosive sour service. Sour service 9as been prescribe# in t9is case base# on t9e ST+ /2;;;psi for 66 an# 21;;psi for 66 an# t9e upper fi'ure for  2S in Section 3.3.17 i.e. 1;;;ppm. T9is resu*ts in a 2S partia* pressure of 13.4:+a for 66an# 1.":+a for 66. T9e protoco* for specif-in' e**9ea# materia* c*ass is to state t9e materia* c*ass it9 t9e  2S partia* pressure a##e# as a suffi67 e'. ))B 1.":+a. T9erefore7 t9e specification for t9e e**9ea#s7 c9o:es an# f*o*ine iso*ation va*ves s9a** be as fo**os •

  ))B13.4:+a Stain*ess Stee*.

•

  ))B1.":+a Stain*ess Stee*

9.2

0rocess *+uipment

9. 2. 1

, enera%

T9e fo**oin' tab*es summarise t9e materia*s to be use# for t9e process e@uipment on bot9 t9e 66 an# 66 e**9ea# p*atforms. Un*ess specifica**- state#7 t9ese recommen#ations app*- e@ua**- to bot9 p*atforms.

+a'e ";

9 . 2. 2

, a s i f t /i r st B a% v e On 6 / BO 8 > , as  i ft < e a# e r an # / % o= % i n es

OperatinService

De9-#rate# natura* 'as it9 composition #efine# in Section 3.3.2.

!a(imum Temperature

;QC

0ressure

12"; psi /42;:+a

Corrosion Dama-e !ec)anism6s8

Interna* corrosion #ue to et 'as from intermittent process upsets or resi#ua* ater from preBcommissionin'. See corrosion rates in Appen#i6 2 ca*cu*ate# usin' NORSOG !"; an# #iscussion in Section ".1. Corrosion i** on*- be #ue to occasiona* upsets of t9e  p*atform #e9-#ration unit. So corrosion is e6pecte# to be mar'ina*.

Topsi#e pipin' e6pose# to marine environment.

2S partia* pressure is 4.:+a7 9ic9 is 'reater t9an t9e *eve* prescribe# bNAC% !R;18"  ISO 1"1" for sour service /;.3:+a. So sour service rate# materia*s are re@uire#. %6terna* corrosion from marine environment. !iti'ate corrosion usin' protective coatin's. !ateria%s

+ipin'7 )*an'es an# )ittin's Carbon Stee* >a*ves /)irst >a*ve On Carbon Stee* =o#- it9 31( trim. )asteners Refer to Section 8. for 'ui#ance.

Corrosion A%%o=ance

3.;mm

Ot)er Interna% Corrosion 0rotection

T9e pipin' s9ou*# be iso*ate# from t9e incomin' 'as *ift riser usin' a !ono*it9ic Iso*ation Foint /!IF *ocate# before t9e )irst >a*ve On.

+a'e "1

9 .2 .3

0 ro #u ct io n / %o =% in es

+a'e "2

OperatinService

!u*tip9ase f*ui# containin' oi*7 pro#uce# ater an# 'as it9 composition #escribe# in Section 3.3. i'9 temperature topsi#e pipin' e6pose# to marine environment.

!a(imum Temperature

11;QC

0ressure

24; psi' /15. bar'


Corrosion from 9i'9 temperature saturate# 9-#rocarbon it9 9i'9 CO 2 an# 2S composition. 2S partia* pressure is ;.22:+a s-stem7 9ic9 is *ess t9an t9e *eve* prescribe# bNAC% !R;18"  ISO 1"1" for sour service /;.3:+a. oever7 'iven t9at t9e 2S composition is c*ose to t9e sour *eve* it is 'oo# in#ustr- practice to specifsour service re@uirements to a**o for acci#enta* e** sourin' etc. %6terna* corrosion of 9i'9 temperature pipin' in a marine environment. +ipin' i** be prone to 9i'9 coatin' brea:#on an# 9en coup*e# it9 t9e fact t9e pipin' is on unmanne# p*atforms7 t9en an e6terna* corrosion a**oance of 1."mm s9ou*# be consi#ere#. Instea# of usin' carbon stee*7 #up*e6 stain*ess stee* mabe use#. T9e #up*e6 stain*ess stee* must be coate# to operate at 11;QC.

!ateria%s

Carbon stee* accor#in' to t9e corrosion mo#e* outputs s9on in Appen#i6 2 s9os 'oo# resistance to corrosion it9 a pre#icte# meta* *oss beteen 1.3B ".2mm. oever7 t9e in9ibitor s-stem injects corrosion at one point for eac9 f*o*ine. If t9is sin'*e point fai*s t9en t9e f*o*ine i** 'o it9out in9ibition for a s9ort perio# of time /as it is an unmanne# p*atform an# t9is i** *ea# to 9i'9 amounts of corrosion t9an as pre#icte# b- t9e NORSOG mo#e*s. A*so7 #ue to t9e 9i'9 e6terna* temperatures t9ere is a concern it9 t9e use of or'anic coatin's #ue to 9i'9 coatin' brea:#on factors an# t9at maintenance i** be minima* 'iven t9at t9e f*o*ines are on an unmanne# p*atform. T9e use of 22Cr #up*e6 stain*ess stee* at 11;QC ou*# not re@uire an interna* corrosion a**oance but ou*# sti** 9ave to be coate# to 'uar# a'ainst severe pittin' corrosion. A 22Cr #up*e6 stain*ess stee* 9as a critica* pittin' temperature of 4;QC an# s9ou*# not be use# above t9is temperature it9out an e6terna* coatin'. T9e cost #ifference to 'o to a 2"Cr super #up*e6 stain*ess stee* is pro9ibitive /ie Carbon stee* versus 22Cr DSS an# 2"Cr SDSS is US`1";;tonne7 US`247";;tonne. an# US`327;;;tonne respective*- an# not arrante# in t9is case. At e*evate# temperature t9e or'anic coatin's ten# to brea: #on an# resu*tant e6terna* corrosion can be @uite severe. !an- operators ten# to use a T9erma**Spra-e# A*uminium coatin' on 9i'9 temperature pipin' in a marine atmosp9ere. T9e t9ic:ness of t9e coatin' is a compromise of obtainin' suitab*e pore over*ap 9i*st maintainin' t9erma* e6pansion compatibi*it- it9 t9e substrate. In t9is case a coatin' of 14;Lm t9ic: is #eeme# suitab*e. T9e coatin' s9a** be sea*e# usin' a a*:-# si*icone topcoat. 1. +ipin' f*an'es an# fittin's T9e recommen#ation is e6terna**- coate# #up*e6 stain*ess stee*H e6terna* coatin' to be 14;Lm t9ic: T9erma**- Spra-e# A*uminium

+a'e "3

an# sea*e# it9 an A*:-# Si*icone. >a*ves 22Cr #up*e6 so*i# va*ve bo#-. )asteners Refer to Section 8. for 'ui#ance. As an alternative (if schedule and cost become a project driver):

2. +ipin'7 f*an'es an# fittin' Sour service carbon stee* it9 a corrosion a**oance an# e6terna**- coate# it9 14;Lm t9ic: T9erma**- Spra-e# A*uminium an# sea*e# it9 an A*:-# Si*icone. >a*ves Carbon stee* bo#- it9 Incone* 2" over*a- of ette# areas an# e6terna**- coate# it9 14;Lm t9ic: T9erma**- Spra-e# A*uminium an# sea*e# it9 an A*:-# Si*icone.

Corrosion A%%o=ance


1.

; mm if t9e recommen#e# #up*e6 is se*ecte#

2.

/8mm 7 mm  if t9e a*ternate /option 2 #escribe# above is se*ecte# an# no cre#it 'iven to p bufferin' from pro#uce# ater.

3.

3mm if t9e a*ternate /option 2 #escribe# above is se*ecte# an# %+I( accept cre#it #ue to p bufferin' from pro#uce# ater.

Corrosion in9ibition to be injecte# upstream of t9e c9o:e va*ve.

+a'e "

9. 2. 

Test
+a'e ""

OperatinService


!a(imum Temperature

11;QC

0ressure

24; psi' /15. bar'


Corrosion from 9i'9 temperature saturate# 9-#rocarbon it9 9i'9 CO 2 an# 2S composition. 2S partia* pressure is ;.22:+a s-stem7 9ic9 is *ess t9an t9e *eve* prescribe# bNAC% !R;18"  ISO 1"1" for sour service /;.3:+a. oever7 'iven t9at t9e 2S composition is c*ose to t9e sour *eve* it is 'oo# in#ustr- practice to specifsour service re@uirements to a**o for acci#enta* e** sourin' etc. %6terna* corrosion of 9i'9 temperature pipin' in a marine environment. +ipin' i** be prone to 9i'9 coatin' brea:#on an# 9en coup*e# it9 t9e fact t9e pipin' is on unmanne# p*atforms7 t9en an e6terna* corrosion a**oance of 1."mm s9ou*# be consi#ere#.

!ateria%s

Carbon stee* accor#in' to t9e corrosion mo#e* outputs s9on in Appen#i6 2 s9os 'oo# resistance to corrosion it9 a pre#icte# meta* *oss beteen 1.3B ".2mm.. T9e corrosion mo#e* is :non to be e** it9in its *imits for t9e f*o*ine con#itions presente# 9ere. T9e test 9ea#er i** be supp*ie# it9 corrosion in9ibitor from mu*tip*e f*o*ines an# t9erefore in9ibition effectiveness s9ou*# remain 9i'9. At e*evate# temperature t9e or'anic coatin's ten# to brea: #on an# resu*tant e6terna* corrosion can be @uite severe. !an- operators ten# to use a T9erma**Spra-e# A*uminium coatin' on 9i'9 temperature pipin' in a marine atmosp9ere. T9e t9ic:ness of t9e coatin' is a compromise of obtainin' suitab*e pore over*ap 9i*st maintainin' t9erma* e6pansion compatibi*it- it9 t9e substrate. In t9is case a coatin' of 14;Lm t9ic: is #eeme# suitab*e. T9e coatin' s9a** be sea*e# usin' a a*:-# si*icone topcoat. +ipin'7 f*an'es an# fittin' Sour service carbon stee* it9 a corrosion a**oance an# e6terna**- coate# it9 14;Lm t9ic: T9erma**- Spra-e# A*uminium an# sea*e# it9 an A*:-# Si*icone. >a*ves Carbon stee* bo#- it9 Incone* 2" over*a- of ette# areas an# e6terna**- coate# it9 14;Lm t9ic: T9erma**- Spra-e# A*uminium an# sea*e# it9 an A*:-# Si*icone. )asteners Refer to Section 8. for 'ui#ance.

Corrosion A%%o=ance

1.

/8mm 66 mm 66 if no cre#it 'iven to p bufferin' from pro#uce# ater.

2.

3mm if 66 accept cre#it #ue to p bufferin' from pro#uce# ater.

Ot)er Interna% Corrosion

Corrosion in9ibition to be injecte# upstream of t9e c9o:e va*ve to ensure 9ea#er is covere# b- t9e in9ibition.

+a'e "

0rotection

+a'e "8

9 . 2. "

0 r o #u c ti o n 0 i - a u nc ) er a n#  a st Ba % ve O ff

OperatinService


!a(imum Temperature

11;QC

0ressure

24; psi' /15. bar'


Corrosion from 9i'9 temperature saturate# 9-#rocarbon it9 9i'9 CO 2 an# 2S composition. T9e #iameter of t9e *ines t9at ma:e up t9e pro#uction 9ea#er an# pi' *aunc9er are bi''er t9an t9ose for t9e f*o*ines an# test 9ea#er /e6pose# to t9e same con#itions 9ic9 means t9e amount of s9ear a*on' t9e a** is *oer an# 9ence t9e in9ibition is more effective. A*so7 t9e corrosion in9ibitor is supp*ie# to t9e pro#uction 9ea#er t9rou'9 mu*tip*e injection sites7 so if one injector 'oes #on7 t9ere is sti** a 'oo# supp*- of corrosion in9ibitor supp*ie# t9rou'9 t9e ot9er f*o*ines. Refer to Appen#i6 2 for t9e corrosion mo#e* resu*ts. 2S partia* pressure is ;.22:+a s-stem7 9ic9 is *ess t9an t9e *eve* prescribe# bNAC% !R;18"  ISO 1"1" for sour service /;.3:+a. oever7 'iven t9at t9e 2S composition is c*ose to t9e sour *eve* it is 'oo# in#ustr- practice to specifsour service re@uirements to a**o for acci#enta* e** sourin' etc. %6terna* corrosion of 9i'9 temperature pipin' in a marine environment. +ipin' i** be prone to 9i'9 coatin' brea:#on an# 9en coup*e# it9 t9e fact t9e pipin' is on unmanne# p*atforms7 t9en a corrosion a**oance of 1."mm s9ou*# be consi#ere#. Instea# of usin' carbon stee*7 #up*e6 stain*ess stee* mabe use#. T9e #up*e6 stain*ess stee* must be coate# to operate at 11;QC

!ateria%s

+ipin'7 )*an'es an# )ittin's Sour service carbon stee* it9 corrosion a**oance an# e6terna**- coate# it9 14;Lm t9ic: T9erma**- Spra-e# A*uminium an# sea*e# it9 an A*:-# Si*icone. >a*ves7 /inc*u#in' (>O Carbon stee* bo#- it9 Incone* 2" over*a- of ette# areas an# e6terna**- coate# it9 14;Lm t9ic: T9erma**- Spra-e# A*uminium an# sea*e# it9 an A*:-# Si*icone. )asteners Refer to Section 8. for 'ui#ance.

Corrosion A%%o=ance

Ot)er Corrosion 0rotection

1.

.;mm Inc*u#in' /1."mm e6terna* if no cre#it 'iven to p bufferin' from pro#uce# ater.

2.

3mm if 66 accept cre#it #ue to p bufferin' from pro#uce# ater.

Corrosion in9ibitor to be injecte# upstream of t9e c9o:e va*ves. T9e pipin' s9ou*# be iso*ate# from t9e incomin' 'as *ift riser usin' a !ono*it9ic Iso*ation Foint /!IF *ocate# after t9e (ast >a*ve Off.

+a'e "4

9.3

Uti%it ' *+uipment

9. 3. 1

/ ue% ,as S'st ems

OperatinService

De9-#rate# natura* 'as it9 composition #efine# in Section 3.3.2.

!a(imum Temperature

;QC

0ressure

12";psi /42;:+a


Interna* corrosion #ue to et 'as from intermittent process upsets or resi#ua* ater from preBcommissionin'. See corrosion rates in Appen#i6 2 ca*cu*ate# usin' NORSOG !"; an# #iscussion in Section ".1. Corrosion i** on*- be #ue to occasiona* upsets of t9e  p*atform #e9-#ration unit. So corrosion is e6pecte# to be mar'ina*.

Topsi#e pipin' e6pose# to marine environment.

2S partia* pressure is 4.:+a7 9ic9 is 'reater t9an t9e *eve* prescribe# bNAC% !R;18"  ISO 1"1" for sour service /;.3:+a. So sour service rate# materia*s are re@uire#. %6terna* corrosion from marine environment. !iti'ate corrosion usin' protective coatin's. !ateria%s

+ipin'7 fittin's an# f*an'es Sour service carbon stee* it9 corrosion a**oance. >a*ves Carbon Stee* =o#- it9 31( trim. )asteners Refer to Section 8. for 'ui#ance.

Corrosion A%%o=ance

3.;mm


Ni*

+a'e "5

9. 3. 2

O pen Drai n s

+a'e ;

OperatinService

Spi**a'es from c9emica* injection s-stem7 *ubricants7 fue* 'as s:i# pans7 pi' receiver #ebris. Topsi#e pipin' e6pose# to marine environment

!a(imum Temperature

;QC

0ressure

Atmosp9eric


T9e open #rain s-stem is to be resistant to a variet- of 9-#rocarbons an# c9emica*s. T9e #rains i** be e6pose# to aci#ifie# ater from process trains. Corrosion rates are not e6pecte# to be 9i'9 'iven t9e #rains are at ambient temperature an# atmosp9eric pressure. T9e #rains i** co**ect so*i# matter an# t9erefore i** be e6pose# to un#er #eposit corrosion. Due to t9e intermittent use of t9e #rains t9ere is a ris: t9at t9e pipin' i** be e6pose# to sta'nant f*ui#s. Open #rains are often contaminate# it9 microbacteria7 9ic9 *ea#s to fou*in' an# b*oc:a'e an# !IC fai*ure of most meta*s. !ateria*s suc9 as &R+BC i** provi#e suitab*e corrosion resistance an# re@uire *ess inspection. Open #rain s-stems are often *eft off inspection pro'rams. A*ternative*- 9eav- a** carbon stee* can be use#. T9e open #rain vesse* is 2;;;mm *on' 6 5;;mm #iameter an# contains 2 eirs an# a #oncomer. Due to t9e siJe of t9is vesse* an# t9e comp*e6it- of t9e interna* appurtenances7 it is recommen#e# t9at t9e vesse* be ma#e of #up*e6 stain*ess stee*. UNS S322;" is recommen#e# in t9is case as it is supp*ie# it9 a minimum 'uarantee# mo*-b#enum content 9ic9 i** 9e*p impart better corrosion resistance. If a *ar'er #iameter vesse* can be accommo#ate# on t9e  an#  p*atform topsi#es7 t9en t9e vesse* mabe manufacture# usin' 9eav- a** carbon stee*. T9e insi#e of t9e vesse* is to be coate# it9 a '*ass f*a:e epo6- or =e*Jona 1351. T9e eirs s9a** be ma#e to be bo*te# into p*ace after t9e vesse* is coate#. T9e e#'es of t9e eirs s9ou*# be roun#e# to ensure an# an even coatin' over t9e e#'e 9ic9 i** be susceptib*e to #ama'e if not t9ic: enou'9. T9e eirs s9a** be coate# usin' t9e same s-stem use# for t9e vesse* interna* coatin'.

!ateria%s

+ipin' &*ass Reinforce# +*astic /&R+BC eav- a** carbon stee*. >a*ves Nic:e* a*uminium bronJe is common for &R+ pipin' s-stems. )or carbon stee* pipin' use# rubber *ine# carbon stee* va*ves )asteners Refer to Section 8. for 'ui#ance. Open #rain vesse* s9ou*# be fabricate# form UNS S322;" Dup*e6 Stain*ess Stee*. +ump Carbon stee* it9 martensitic stain*ess stee* impe**ers.

Corrosion

mm for carbon stee*.

+a'e 1

A%%o=ance Ot)er Interna% Corrosion 0rotection

+ipin' to be free #rainin' an# free from *o spots an# #ea# *e's. +rovision for t9e intermittent #osin' of bioci#e s9a** be inc*u#e# on eac9 #rain *e'. Interna* eirs of t9e carbon stee* vesse* to be removab*e for easier coatin'.

9 . 3. 3

B en t a n# C % os e# D r ai n s an # Ben t S cr ub b er

OperatinService

Co**ection of *i@ui# an# vapour stream from f*o*ine #rains an# vents7 an# *i@ui#s from t9e open #rain sump.

!a(imum Temperature

;QC

0ressure

1"; psi.


)*ui#s enterin' t9e c*ose# #rains from t9e process s9ou*# be at *o pressure7 t9us a**oin' t9e use of carbon stee* it9 a 3mm corrosion a**oance.

!ateria%s

+ipin'7 f*an'es an# )ittin's Carbon stee*

To re#uce t9e ris: of #ama'e from sta'nant f*ui#s t9e pipe or: must be #esi'n to be free #rainin' avoi#in' *o spots an# #ea# *e's.

>esse* an# +ipin' >a*ves Carbon stee* it9 31( trim )asteners Refer to Section 8. for 'ui#ance. >ent scrubber Carbon stee* an# interna**- coate# it9 a &*ass )*a:e %po6- or =e*Jona 1351. +ump Carbon stee* it9 stain*ess stee* impe**ers Corrosion A%%o=ance

3.;mm


+ipin' to be free #rainin' an# free from *o spots an# #ea# *e's.

9 .3 .

C )e mi ca % In je ct io n 0a c@ a- e

C9emica* injection i** be from t9e 666 p*atform it9 on*- pipin'7 #istribution manifo*#7 c9o:es an# injection points provi#e# on t9e 66 an# 66 p*atforms. +ipin' s9a** be AST! A25 &ra#e 31( it9 a 'uarantee# minimum2." !o*-b#enum an# ma6imum Roc:e** = 9ar#ness of 4;. )ittin's s9a** a*so be 31( it9 a 'uarantee# minimum2." !o*-b#enum.

+a'e 2

9 .3 ."

C CB T 0 o= er , en er at io n

T9e C*ose# C-c*e >apour Turbines /CC>T is a proprietar- supp*ie# items an# t9e ven#or s9a** be responsib*e for ensurin' t9e materia*s of construction are suitab*e. As a minimum t9e CC>T s9a** be supp*ie# in UNS S31;3 austenitic stain*ess stee* in comp*iance it9 ISO1"1".3  NAC% !R;18".

9 .3 .4

< '# ra u% ic 0i pi n- S's te ms

-#rau*ic pipin' s9a** be AST! A25 &ra#e 31( it9 a 'uarantee# minimum 2." !o*-b#enum an# ma6imum Roc:e** = 9ar#ness of 4;. )ittin's s9a** a*so be 31( it9 a 'uarantee# minimum2." !o*-b#enum. If pipin' is to be e6pose# to temperatures 'reater t9an ;QC t9en tubin' an# fittin's s9a** be 2"Cr super #up*e6 stain*ess stee* or aste**o- C28 /UNS N1;28.

9 .3. ?

I nst ru me nt at io n

Due to t9e sour service con#itions in t9e 66 fie*#7 t9e instrumentation use# in #irect contact it9 t9e pro#uction an# 'as *ift e@uipment an# pipin' s9a** be constructe# out of materia*s in comp*iance it9 ISO 1"1". In a** cases7 t9e instrument supp*- ven#or s9a** c9ec: t9e materia*s of t9eir instrument for compatibi*it- it9 t9e process con#itions. Instrumentation pipin' /inc*u#in' compression fittin's7 an# screen #evices is acceptab*e for  an#  in UNS S31;;7 provi#e# t9e e6posure temperature of t9e tubin' is maintaine# be*o ;QC. If t9e e6posure temperature is 'reater t9an ;QC7 t9en t9e tubin'7 compression fittin's an# associate# tubin' e*ements7 s9a** be 2"Cr super #up*e6 stain*ess stee* /UNS S328"; or aste**o- C28 /UNS N1;28. A** tubin' s9a** comp*- it9 t9e re@uirements of ISO 1"1"B3 for ma6imum sour service e6posure con#itions /temperature7 an# p 2S an# materia* 9ar#ness. UNS S3;;; /&ra#e 3; an# its #erivatives s9a** not be use# for an- e@uipment on 66 or 66. UNS S3;;; is susceptib*e to c9*ori#e stress corrosion crac:in' at temperatures c*ose top ambient con#itions an# t9erefore cannot be use# for pressure containment. UNS S3;;; is 9i'9*- susceptib*e to pittin' in marine environments an# t9erefore is not appropriate for instrument enc*osures or junction bo6es. !ateria*s se*ection information for a** ot9er instrumentation is provi#e# in Tab*e 4 B12. Tab%e 9&12 Instrumentation !ateria% Se%ection C)art Instrumentation

T9ermoe**

+ressure &au'e Sitc9  %*ement  Soc:et

(eve* Instruments

Service

!ateria%

Temp M ;QC

UNS S31;;

Temp P ;QC

UNS N1;28 /aste**o- C28

Temp M ;QC

UNS S31;;

Temp P ;QC

UNS N1;28 /aste**o- C28

Temp M ;QC

=o#-  C9amber  UNS S31;3 /31( Disp*acer  )*oat  UNS S31;3 /31(

Temp P ;QC

=o#-  C9amber  N1;28 /aste**o- C28 Disp*acer  )*oat  N1;28 /aste**o- C28

Transmitter 

Temp M ;QC

=o#- B UNS S31;3 /31(

+a'e 3

Instrumentation

Service

Contro**er

!ateria%

%*ement B UNS S31;3 /31( Temp P ;QC

=o#- B N1;28 /aste**o- C28 %*ement B N1;28 /aste**o- C28

Contro* >a*ves  !onoB=*oc: >a*ves

Temp M ;QC

=o#- B UNS S31;3 /31( Trim B UNS S31;3 /31(

Temp P ;QC

=o#-  Carbon Stee* /Sour Service Trim B N1;28 /aste**o- C28

Safet- >a*ves

Temp M ;QC

=o#-=onnet B UNS S31;3 /31( NoJJ*e  Disc  UNS S31;3 /31( Sprin'  =e**os  UNS N;2" /Incone* 2"

Temp P ;QC

=o#-=onnet  Carbon Stee* /Sour Service NoJJ*e  Disc  UNS N1;28 /aste**o- C28 Sprin'  =e**os B UNS N;2" /Incone* 2"

Orifice +*ate

Temp M ;QC

)*an'e =o#- B UNS S31;3 /31( +*ate B UNS S31;3 /31(

Temp P ;QC

)*an'e =o#- B UNS N1;28 /aste**o- C28 +*ate B UNS N1;28 /aste**o- C28

!u*tip9ase )*ometer

!ateria*s to be a#vise# b- t9e ven#or for approva* b- %+I(.

+a'e 

9 .3 .9

a s) Do =n at er S's te m

OperatinService

,ater co**ecte# from t9e 9e*i#ec:

!a(imum Temperature

Ambient

0ressure

Atmosp9eric


,ater from t9e 9e*i#ec: i** contain c9*ori#es as9e# from t9e surface.

!ateria%s

Tan: &R+ or +o*-prop-*ene /++ it9 UNS S31;3 austenitic stain*ess stee* fittin's.

Topsi#e marine environment.

>a*ves &R+7 ++ or Nic:e* a*uminium bronJe for &R+ pipin' +ipin' &R+ or ++. Corrosion A%%o=ance

Ni*


None

+a'e "

5.

! AT AT * R I A  S *  * C T I O N & 0 I 0 *  I N * S

5. 1

! at at er er i a% a% s an an # C or or r o s i on on A% A% %o % o = an an c e

5 . 1. 1. 1

 i ne n e pi p i p e ! an a n uf u f a ct ct u ri ri n - 0 ro r o c es es se se s

)or t9e *inepipe siJes /DN4;7 DN1;;7 D3"; consi#ere# for t9e -#ra #eve*opment t9ere are to *inepipe manufacturin' processes common*- use#7 t9e- are •

Seam*ess *inepipe manufacture b- +i*'er or !annesmann processesH

•

i'9 )re@uenc- In#uction /or Resistance ,e*#e# *inepipe /),.

=ot9 processes are e6tensive*- use# t9rou'9 t9e oi* an# 'as in#ustr- for t9e transport of oi* an# 'as pro#ucts in bot9 sour an# nonBsour app*ications. app*ication s. Tra#itiona**-7 ), *inepipe 9as not been t9e preferre# c9oice for 'aseous service #ue to t9e ris: of t9e e*#e# seam sp*ittin'. T9ere 9ave been ver- fe inci#ents of subsea ), pipe*ines sp*ittin' a*on' t9e seam since e*#in' fre@uencies 9ave increase# to e** above 4;:J in t9e ear*- 158;[s. Common e*#in' fre@uencies are no of t9e or#er of 1";B3;;:J an# t9is pro#uces consistent 9i'9 @ua*it- e*#s. oever7 it 9as not been unti* 2;;;[s t9at ), pipe 9as been use# e6tensive*- for 'aseous service. service . T9ere are severa* e6amp*es in Austra*ia 9ere 9ere ), 9as been been use# for 'aseous 'aseous serviceH serviceH t9ese inc*u#e inc*u#e sa*es 'as in in t9e Tasm Tasmania ania &as +ipe*ine /3;;K :m *on' an# ra 'as at t9e Santos +atricia =a*een #eve*opment /2:m *on'. A revie of t9e supp*- recor#s of to Fapanese *inepipe mi**s an# one Gorean *inepipe mi** s9os t9at sour ), *inepipe 9as been use# offs9ore b- Arco in t9e UG7 ,oo#si#e in Austra*ia an# Nors: S9e** in Nora- it9 stren't9 *eve*s e@uiva*ent to t9ose consi#ere# for t9e -#ra #eve*opment /; to ". T9ese ere or#ere# or#ere# as ear*- as 155;. 155;. Specific #etai*s about about t9e c9emistr- for t9ese fie*#s fie*#s are not #etai*e# on t9e mi**s supp*- 9istor- s9eets. Nippon Stee* in i:ari Cit-7 Fapan7 c*aim to be pro#ucin' a *ot more sour service DN> *inepipe it9 2"; tonnes of sour *inepipe pro#uce# per mont9 b- t9is mi** /2; of pro#uction. +rob*ems suc9 as preferentia* preferentia* corrosion of t9e e*# seam un#er 9i'9 CO2 an# sour service con#itions are no *on'er a prob*em #ue to t9e improve# 9omo'eneit- ac9ieve# it9 mo#ern *inepipe e*#in' mac9ines7 t9is is #emonstrate# in t9e *aborator- report from Nippon Stee* in Appen#i6 Appen#i6 ". !o#ern mi** NDT tec9ni@ues tec9ni@ues uti*ise automatic u*trasonic u*trasonic testin' to inspect t9e strip e#'es prior to e*#in'7 t9e fu** pipe bo#- an# t9en t9e e*# seam to ensure t9e e*# seam is #efect free. T9is *eve* of NDT is unprece#ente# for an- ot9er *inepipe form. Oi* 9as been *on' transporte# subsea in ), pipes. ,9en ), pipe is use# to an# from p*atforms it is a norma**norma**accepte# practice to ma:e t9e risers out of seam*ess *inepipe in p*ace of t9e ),. ,it9 t9e cost of ), in 2;;8 current*- at ÙS5";tonne an# seam*ess *inepipe current*- at ÙS22;;B US`2";;tonne t9e use of ), is increasin' it9in t9e oi* an# 'as in#ustr-. If cost an# sc9e#u*e become priorit- #rivers for t9e -#ra project t9en it is recommen#e# t9at furt9er investi'ation be carrie# out on t9e viabi*it- of ), pipe in sour mu*tip9ase service b- surve-in' t9e various *inepipe mi**s supp*-in' DN> OS )1;1 comp*iant ), *inepipe. Unti* suc9 furt9er investi'ation can be un#erta:en to #emonstrate t9e suitabi*it- of ), for t9e 66 project t9en it is recommen#e# t9at t9e )%%D procee#s on t9e basis of seam*ess *ine pipe t9rou'9out.

5 .1 . 1 .2 .2

0 ip i p e% e % in i n es e s : Ri Ri se s e rs r s & *( * ( po po rt rt

T9e pipe*ines an# risers for t9e 66 an# 66 e6port pipe*ines to 66s9a** be #esi'ne# an# manufacture# in accor#ance it9 DN> OS )1;1. T9e *inepipe s9a** be rate# for sour service even t9ou'9 t9e  2S partia* pressure is just be*o t9e critica* *eve* #efine# in ISO 1"1"  NAC% !R;18". T9e *inepipe i**

+a'e 

re@uire a mm corrosion a**oance base# on t9e conservative corrosion mo#e**in' /refer to Appen#i6 2 resu*ts an# not ta:in' cre#it for potentia* benefit of p bufferin' from an- pro#uce# ater t9at mabe present in t9e pro#uction stream. T9is corrosion a**oance is base# on a corrosion in9ibitor in9ibito r efficienc- of 55 an# avai*abi*it- of 547 9ic9 is in *ine it9 t9e pro#uction up time specifie# in t9e -#ra Desi'n =asis for e@uipment e@uipment avai*abi*it- Ref 1. Section 8..2. T9e c9oice of process of manufacture is at 66 #iscretion7 t9e DN> OS )1;1 #esi'nations are summarise# be*o. •

DN> OS )1;1 S!(S &ra#e 1" ISD

•

DN> OS )1;1 ), &ra#e 1" ISD.

Accor#in' to t9e t9e #esi'nations #esi'nations above t9e t9e *inepipe 9as t9e fo**oin' fo**oin' supp*ementarsupp*ementarre@uirements re@uirements •

S!(S7 seam*ess *inepipeH

•

),7 i'9 )re@uenc- ,e*#e# *inepipeH

•

&ra#e 1"7 1"!+a S!$S or e@uiva*ent to A+I "( ;H

•

(eve* 1 NDT7 re@uire# for 'aseous an# mu*tip9ase serviceH

•

Sour service supp*ementarre@uirement /SH

•

%n9ance# #imensiona* properties /D7 to assist it9 constructabi*it-.

T9e riser sp*as9 Jone s9a** re@uire protection over an# above t9at for t9e submer'e# riser an# t9e topsi#e pipin' #ue to t9e et7 c9*ori#e aerate# environment. An e6terna* corrosion corrosion a**oance a**oance for t9e atmosp9eric atmosp9eric an# an# sp*as9 Jones Jones base# on on t9e fo**oin' fo**oin' ru*e of t9umb Riser corrosion a**oance  2mmK1mm /TB2;1; So for t9e 66 an# 66 risers at 11;QC7 11;QC7 t9e e6tra corrosion a**oance a**oan ce ou*# re@uire to be 11mm. 11mm. T9is corrosion a**oance is impractica* an# conventiona* po*-c9*oroprene /neoprene coatin's are not suitab*e for operatin' continuous*- at 9i'9 temperatures as t9e- i** a'e 9ar#en an# fracture. T9erefore it is propose# to insta** a !one* c*a# stee* s*eeve in t9e riser sp*as9 Jone usin' a carbon stee* s*eeve beteen t9e !one* an# t9e riser pipe7 t9e carbon stee* s*eeve in effect becomes t9e corrosion a**oance. a**oance . It is propose# t9at t9e s*eeve be fabricate# from a 12mm ro**e# p*ate an# t9e !one* c*a##in' be 3mm. )or t9e risers at 667 t9e e6terna* corrosion a**oance for t9e  riser can be re#uce# #ue to t9e *oer arriva* temperature temperat ure of 34QC at  an# 8QC at . oever7 'iven t9e importance of t9ese risers an# t9e severit- of t9e corrosion environment it is recommen#e# to #up*icate t9ese !one* c*a# s*eeves at a** pro#uction risers. %+I( 9ave #irecte# t9at t9e pipe*ine an# riser materia* a** t9ic:ness s9ou*# be i#entica*.

5 .1 . 1 .3 .3

0 ip i p e% e % in i n es e s : Ri Ri se s e rs r s H ,a , a s  if if t

T9e pipe*ines an# risers for t9e 66 'as *ift pipe*ines to 66 an# 66 s9a** be #esi'ne# an# manufacture# in accor#ance it9 DN> OS )1;1. T9e *inepipe s9a** be rate# for sour service. . T9e corrosion corrosi on mo#e**in' /refer to Appen#i6 2 resu*ts 9ave overBestimate# t9e corrosion rate as t9e mo#e* assumes t9e 'as is saturate#7 9ic9 is not t9e case. In or#er to temper t9e overBestimation overBestimation of t9e corrosion a**oance a va*ue for t9e amount of time t9e pipe*ine i** be e6pose# to et 'as as #erive# an# use# to proportion t9e corrosion rate #on. In t9is instance it as assume# t9at t9e pipe*ine i** be e6pose# to up to ; #a-s per -ear /1 of offBspecification 'as an# 9ence i** be e6pose# to

+a'e 8

corrosive con#itions. con#itions. T9e corrosion a**oance a**oance as #erive# as 1 of t9e ca*cu*ate# corrosion corrosion rate assumin' t9at t9e corrosion in9ibitor injection s-stem is 1;; avai*ab*e for t9e s9ort #urations t9e 'as is offBspecification. offBspecific ation. T9e mo#e* for t9e 'as pipe*ine #oes not assume t9e 'as *ift pipe*ine i** be operate# 9en t9e 'as is offBspecification an# t9e in9ibitor s-stem is off*ine7 as t9is ou*# be consi#ere# #oub*e jeopar#-. It is recommen#e# t9at if t9e in9ibition is off*ine an# t9e 'as #e9-#ration train a*so 'oes #on7 t9en pro#uction is s9ut in unti* eit9er unit is brou'9t bac: bac: on *ine. T9e corrosion a**oance #erive# for t9e 'as *ift *ine is 3.;mm base# on t9e out*et con#itions. T9e pipe*ine i** transport for most of t9e time it9 #e9-#rate# sa*es 'as. In case of upsets it is recommen#e# t9at t9e pipe*ine be pi''e# to c*ear an- ater out of *o *-in' areas in t9e pipe*ine. pipe*ine. )or a sma** #iameter 'as pipe*ine it is recommen#e# t9at t9e pipe be manufacture# usin' t9e seam*ess process. •

DN> OS )1;1 S!(S &ra#e 1" ISD /Doub*e Ran#om (en't9H or7

•

DN> OS )1;1 &ra#e "; IS+D Coi*e# (ine +ipe it9 DN> OS )1;1 S!( &ra#e 1" ISD for t9e risers.

Accor#in' to t9e t9e #esi'nations #esi'nations above t9e t9e *inepipe 9as t9e fo**oin' fo**oin' supp*ementarsupp*ementarre@uirements re@uirements •

S!(S7 seam*ess *inepipeH

•

&ra#e 1"7 1" !+a S!$S or e@uiva*ent to A+I "* ;H

•

(eve* 1 NDT7 re@uire# for 'aseous an# mu*tip9ase serviceH

•

Sour service supp*ementarre@uirement /SH

•

%n9ance# %n9ance# #imensiona* properties /D7 to assist it9 constructabi*it-H constructabi*it-H

•

(ine pipe e6pose# to p*astic #eformation e6cee#in' 2 supp*ementarre@uirement /+ re@uire# for Coi*e# (ine +ipe.

T9e 'as *ift risers at 66 an# 66i** operate continuous*continuous*- at temperatures *ess t9an ;QC7 an# a sp*as9Jone coatin' provi#e# b- a 9i'9 @ua*it- po*-c9*oroprene i** be sufficient. As for t9e e6port pipe*ine7 t9e ID of t9e riser s9ou*# be matc9e# to t9at of t9e pipe*ine to ensure free passa'e of pi's. )or t9e 'as *ift pipe*ines it mabe re@uire# to procure a sma** or#er of riser pipe /DR( if pipe*ine is procure# as coi*e# *ine pipe. pipe. In t9is case t9e riser procurement i** be *ess t9an "; tonnes an# accor#in' to DN> OS )1;1 t9e *inepipe mi** is not re@uire# to con#uct manufacturin' proce#ure @ua*ification @ua*ificat ion testin'. T9is is acceptab*e provi#e# t9e mi** performs C9arp- >Bnotc9 impact testin' over a ran'e of temperatures form K2;QC to B;QC to s9o t9at t9e risers 9ave sufficient *o temperature temperature tou'9ness at t9e minimum #esi'n temperature for t9e pipe*ine.

5 .1 .1 . 

0 ip i p e% e% in i n e / it i t ti ti nn- s

+ipe*ine fittin's s9a** be manufacture# in accor#ance it9 DN> OS )1;1 Section 8 an# s9a** be for'e# in accor#ance it9 t9e re@uirements re@uirement s of AST! AST! A5. An- subsea f*an'es s9a** 9ave a rin' 'roove t-pe 'as:et. T9e 'as:et s9a** be manufacture# from Incone* 2" an# t9e rin' 'roove s9a** be e*# over*a-e# it9 Incone* 2".

5 . 1. 1. "

C ) em em ic i c a% a % I nj n j e ct ct i on o n % in i n e 6/ 6 / %a % a t &0 &0 ac a c @8 @8

T9e c9emica* injection s-stem i** be supp*ie# from t9e 66 usin' eit9er a f*at pac: or conventiona* umbi*ica*. T9e f*at pac: umbi*ica* is a simp*e four stee* 9ose umbi*ica* umbi*ica* it9 a po*-meric outer s9eat9. It is recommen#e# t9at t9e f*at pac: be ma#e up usin' continuous 31( tubin' an# a po*-prop-*ene outer s9eat97 if t9e ven#or cannot 'uarantee t9e performance or @ua*it- of t9e e6terna* coatin' of t9e

+a'e 4

tubin' over t9e #esi'n *ife t9en consi#er #up*e6 stain*ess stee*. T9e umbi*ica* ven#or s9a** arrant t9e #esi'n of t9e f*atBpac:7 inc*u#in' materia* performance.

5 . 1. 4

C % am pi n - a n# St r ap pi n - m at er i a% s

T9e )*atB+ac: mabe pi''-bac:e# from 66to 66 an# 66 on t9e 'as *ift pipe*ine. If t9is is #one7 t9en t9e )*atB+ac: s9ou*# be strappe# usin' a comp*iant7 -et tou'9 strappin' materia*. A meta**ic strap is not recommen#e# if t9e strap is to contact t9e )*atB+ac: outer s9eat9 as t9e meta**ic strap can cut into t9e umbi*ica* outer s9eat9. Ot9er operators insta**in' pi''-bac: *ines 9ave use# Gev*ar tm  straps to secure t9e pipes to'et9er. T9e Gev*ar is ver- stron' an# ten#s not to 9ave t9e s9arp e#'es t9at meta**ic straps create. Gev*ar strappin' is more e6pensive t9an meta**ic ban#in'.

5.2

Coatin- S'stems

5 . 2. 1

0 i pe % in e An t i& Co rr os i on C o at i n- S ' st e m

)=% coatin's become increasin'*- 9-#roscopic it9 increase in operatin' temperature  t9is *ea#s to #isbon#ment of t9e coatin' from t9e stee* substrate. It is for t9is reason t9at )=% app*ie# to submarine pipe*ines is *imite# to a ma6imum continuous operatin' temperature some9at *oer t9an t9at specifie# in #r- con#itions. T9e ma6imum operatin' temperature of )=% in submerse# et service is some 2; #e'ree *oer t9an for #r- serviceH it is not recommen#e# to consi#er )=% coatin's for subsea service at continuous operatin' temperatures in e6cess of 5;C. As t9e pro#uction pipe*ine operates at a temperature over 1;;QC t9en t9e practica* c9oice of *inepipe coatin' recommen#e# is a 2mm 3B*a-er po*-prop-*ene coatin'. T9e temperature profi*es 'enerate# #urin' t9e f*o assurance stu#ies s9o t9at t9e pro#uction *ine temperature i** not #rop be*o 5;QC for at *east 3;;;m from t9e 66riser base an# 2;;;m from t9e  riser base. AntiB s*ip ban#s mabe necessar- to be fi6e# to t9e po*-prop-*ene coatin' to stop t9e concrete ei'9t coatin' from s*ippin' off t9e pipe #urin' insta**ation. )or t9e *o temperature 'as *ift pipe*ines /ma6imum continuous operatin' temperature];QC t9e recommen#e# coatin's are •

2mm 3(+%  for coi*e# *ine pipe insta**ation

•

;."mm )=% for risers an# #oub*e ran#om *en't9 *ine pipe

T9e 'as *ift pipe*ine i** not be concrete ei'9t coate#.

5 .2 .2

R is er C oa ti n- S 's te ms

AT!OS0<*RIC ON* T9e atmosp9eric Jone above t9e riser 9an'Boff f*an'e s9a** be coate# usin' an U*tra i'9 =ui*# epo6-. T9e coatin' s9a** be app*ie# to a D)T of 1;;;B1";;Lm an# s9a** be app*ie# to a C*ass 2." /near 9ite meta* b*ast c*eane# surface it9 a 8"B1;; Lm an'u*ar profi*e. T9e atmosp9eric Jone beteen t9e top of t9e sp*as9 Jone coatin'  s9eat9 s-stem to t9e /an# inc*u#in' t9e riser 9an'Boff f*an'e s9a** be coate# usin' a f*ame spra-e# po*-prop-*ene. T9e f*ame spra-e# coatin' s9a** be 2";;Lm t9ic: an# be free from porosit- /test usin' a 9o*i#a- tester. T9e f*ame spra-in' proce#ure 

Gev*ar is a re'istere# tra#ename of t9e Du+ont or'anisation.

+a'e 5

s9a** be @ua*ifie# an# teste# prior to app*ication to t9e 66 an# 66 risers. T9e Coatin' +roce#ure ?ua*ification s9a** be itness b- 66 or its representative.

S0AS< ON* Riser sp*as9 Jones are t-pica**- coate# it9 +o*-c9*oroprene rubber for temperatures up to 5;QC an# for temperatures above t9is7 t9en !one* ;; /UNS N;;; c*a##in' or s9eat9s an# use#. )or 66an# 66 9ere temperature of t9e e6port riser is 11;QC7 t9en !one* ;; is t9e best c9oice for sp*as9 Jone protection. If e6terna* !one* c*a##in' is use# t9e minimum t9ic:ness s9a** be 3mm c*a# over carbon stee* ro**e# p*ate of 12mm t9ic:ness. T9e bottom en# /";;mm of t9e !one* s9eat9 s9a** be s9op coate# usin' t9e same coatin' s-stem as t9e submer'e# Jone coatin' to minimiJe t9e potentia* for 'a*vanic attac:. Simi*ar*-7 t9e top section. s9a** be coate# for a #istance of 3;;mm it9 t9e atmosp9eric Jone coatin' to avoi# 'a*vanic attac:. )or t9e 'as *ift risers it is recommen#e# t9at +o*-c9*oroprene rubber be use# for t9e riser sp*as9 Jone protection.

SU;!*R,*D ON* T9e submer'e# Jone s9a** be coate# in accor#ance it9 t9e coatin' use# for t9e main pipe*ine coatin'. ;."mm )=% for 'as *ift risers 2.;mm for t9e 3B*a-er po*-prop-*ene risers.

5.3

Cat)o#ic 0rotection

5 .3 .1

S ac ri fi ci a% An o# e S's te m

T9e pipe*ine s-stems s9a** be protecte# usin' sacrificia* ano#es. T9e ano#es s9a** be of t9e brace*et t-pe ma#e of &a*vanum III. T9e #esi'n of t9e amount an# position of brace*et ano#es s9a** be in accor#ance it9 DN> R+ =;1H t9is is more conservative t9an DN> R+ )1;3 Ref 12 but i** provi#e 'reater protection s9ou*# coatin' app*ication not be in strict accor#ance it9 DN> R+ )1;7 9ic9 R+ )1;3 is #epen#ent.

5 . 3. 2

C o rr o si o n 0 r ot e ct i o n S ' st e m I s o %a t i on H ! I J s

T9e subsea pipe*ine an# riser s9a** be e*ectrica**- iso*ate# from t9e p*atform jac:et C+ s-stem an# t9e topsi#e pipin'. T9e insu*ation s9ou*# be ma#e usin' 9i'9 inte'rit- insu*ation joint suc9 as a mono*it9ic iso*ation joint. Care s9a** be ta:en to ensure t9at t9e !IF is not s9ort circuite# b- pipe supports or t9rou'9 contact beteen t9e riser an# t9e jac:et c*amps. Riser c*amps s9a** be *ine# it9 Neoprene rubber to ensure t9e riser is e*ectrica**- iso*ate# from t9e jac:et C+ s-stem. Insu*atin' 'as:ets sets s9a** be use# to iso*ate t9e #up*e6 stain*ess stee* f*o*ines from t9e pro#uction an# test 9ea#ers. An- #rain or vent connections ma#e to t9e #up*e6 stain*ess stee* f*o*ines s9a** a*so be e*ectrica**- insu*ate# usin' insu*atin' 'as:et :its.

+a'e 8;

1.

ASS*T INT*,RI T$ ! AN A,*!*NT

1.1

,e ne ra% 0)i% oso p) '

T9ere s9ou*# be an inte'ritmana'ement p*an #eve*ope# for t9e 66 +*atform base# an# subsea assets. T9is inte'ritmana'ement p*an s9ou*# aim to provi#e t9e fo**oin' outcomes •

+rovi#e a #ocumente# an# au#itab*e s-stem t9at enab*es oner to measure an# mana'e t9e onB'oin' ris: of t9e 66 an# 66 p*atforms an# intrafie*# pipe*inesH

•

%nsure t9at t9e environmenta* an# safet- inte'rit- of t9e s-stem is maintaine# b- #etectin' an#eterioration before *ea:a'e of pro#uction f*ui#sH

•

%nsure t9at t9e assets remain fit for purposeH

•

%nsure t9at t9e assets function in accor#ance it9 t9e *e'is*ative approva*s for t9e #eve*opmentH

•

To ensure t9e assets continue to meet t9e pro#uction re@uirements of t9e #eve*opmentH

•

To prevent brea:#ons an# unp*anne# outa'esH

•

To enab*e corrective action to be carrie# out in a time*- manner an# to maintain t9e s-stems fai*ure ris:s to As (o as Reasonab*- +ossib*e /A(AR+.

T9ese outcomes s9ou*# be obtaine# b- #ocumentin' a s-stem t9at consi#ers a** of t9e corrosion activities as part of t9e s-stem operation. T9e fo**oin' activities are consi#ere# core corrosion en'ineerin' activities7 9ic9 form a part of t9e Inte'rit- !ana'ement +*an •

Corrosion miti'ation /refer to Sections 4 an# 5H

•

Corrosion monitorin' /refer to Section 11H

•

Corrosion #ata co**ection an# assessment /refer to Section 12.

T9is s-stem is best #ocumente# prior to t9e commissionin' of t9e s-stem an# s9ou*# incorporate input from bot9 t9e corrosion  inspection en'ineer as e** as operations staff 9o i** be responsib*e for a *ot of t9e #ata 'at9erin' an# corrosion miti'ation e@uipment operation.

1 . 2

R ec om m en #e # Ro ut i ne ! ai n te n an ce Ac t i vi t ie s

+*anne#routine activities are #efine# as t9ose activities t9at 9ave #efine# interva*s an# *ocations in 9ic9 t9e- are carrie# out. T9is section #etai*s t9e t-pe of activities t9at s9a** be inc*u#e# as part of t9e +anna inte'ritmana'ement s-stem. T9e t-pe of activities7 *ocations an# interva*s in 9ic9 t9e- are con#ucte# can var- #epen#in' on t9e fo**oin' •

>ariation in operatin' con#itionsH

•

T9e #etection of anoma*iesfai*uresH

• A#vent of ne tec9no*o'-.

It is recommen#e# t9at 66( prepare a ris: base# inspection p*an to assist in t9e preparation of a traceab*e an# au#itab*e p*atform an# pipe*ine mana'ement p*an. Suc9 a p*an s9a** #ocument an# justif- activities7 *ocations an# return perio#s re@uire# to mana'e onB'oin' ris:.

+a'e 81

It is t9e responsibi*it- of t9e Corrosion an#or Inspection %n'ineer to 9ave t9e most up to #ate :no*e#'e of t9e process7 corrosion mec9anisms an# monitorin' tec9no*o'ies avai*ab*e an# references in t9e 66 an# 66 inte'ritmana'ement s-stem.

1 . 3

0 os si b% e U np %a nn e# Ac t iv it ie s

Unp*anne# or nonBroutine activities re*ate to items suc9 as corrosion fai*ures /i.e. *ea:s7 ruptures or *oss of faci*itiesuti*ities7 an# unp*anne# or opportunistic inspections /suc9 as 9avin' an RO> avai*ab*e #urin' subsea interventions. ,9i*e it is impossib*e to provi#e *on' term p*ans for t9ese situations7 it is possib*e to 9ave in p*ace proce#ures7 or response p*ans7 t9at enab*e t9e capture an# assessment of inspection resu*ts arisin' from t9ese activities. Opportunistic inspections ma- resu*t from an anoma*- 'enerate# from ot9er inspections or monitorin' activities. Information from t9ese activities s9ou*# be processe# in t9e same manner as t9e routine inspections7 inc*u#in' t9e use of t9e #ata as input into t9e corrosion ris: assessment.

+a'e 82

11.

CORROSION !ONITORIN,

11.1

Ai m

T9e aim of corrosion monitorin' is to ensure t9at t9e #esi'n *ife i** not be a#verse*- compromise# #urin' service an# to ensure t9e safe an# economic operatin' *ife of a faci*it-. T9e monitorin' maa*so be use# to optimise inspection interva*s as part of a ris:Bbase# inspection /R=I pro'ramme an# to #etect c9an'es in corrosivit- t9at i** inva*i#ate inspection perio#s or en#an'er t9e p*ant. T9e primar- p9i*osop9- is t9at corrosion monitorin' i** be specifie# 9en 1. C9an'es in t9e operatin' environment can *ea# to si'nificant increase in t9e corrosivit- of t9e environment toar#s carbon stee*7 eit9er it9 or it9out corrosion in9ibitors. 2. (oss of corrosion in9ibition i** *ea# to rapi# meta* *oss. 3. T9e outcome of corrosion monitorin' can *ea# to time*- reBassessment an# a#justment of t9e s-stem of corrosion mana'ement. . !onitorin' cou*# *ea# to optimisation of in9ibitor #osin'. T9e functiona* re@uirement of t9e corrosion monitorin' s-stem is t9at it s9a** #etect an# @uantiftren#s in t9e corrosivit- of t9e f*ui#s an# s9a** #o so it9in a time frame s9ort enou'9 to enab*e t9e Operator to insti'ate or a#just corrosion miti'ation measures before si'nificant meta* *oss 9as occurre#.

11. 2

! on it or in - an # Tes ti n- / ac i% it ie s

S-stems potentia**- at ris: of corrosion i** re@uire corrosion monitorin' faci*ities7 suc9 as corrosion coupons or corrosion probes. ,9ere monitorin' is re@uire#7 to access fittin's s9ou*# be insta**e# for t9e purpose of monitorin' it9 e*ectrica* resistance /%R probes an# corrosion coupons. T9e probes an# coupons s9a** be of a t-pe an# #imension suc9 t9at t9e sensitive e*ement s9a** be in t9e ater p9ase. T9e fo**oin' points s9a** a*so be ta:en into consi#eration •

Some s-stems i** a*so nee# samp*in' points for c9emica* ana*-sis.

•

S-stems at ris: of bacteria contamination i** re@uire bioBprobes an#or samp*e points.

•

Ot9er testin' faci*ities re*evant to corrosion an# inte'ritmana'ement i** be necessar- in t9e appropriate s-stem.

• A** carbon stee* s-stems i** re@uire Non Destructive Testin' at some point in t9eir service *ife.

Some s-stems i** re@uire routine /e.'. mont9*- or @uarter*- NDT at Sentine* points. • A** e@uipment s9ou*# be #esi'ne# an# *ocate# consi#erin' t9e re@uirement for corrosionB

monitorin' tec9nician an#or inspector access. • A** *ocations for corrosion monitorin' an# samp*in' s9ou*# be c*ear*- mar:e# on +EIDs an#

Isometric #rain's. (ocations for Ge- +oint UT at Sentine* points s9ou*# be mar:e# on Isometric #rain's.

+a'e 83

11.3

! oni tori n- !et )o #s

Corrosion monitorin' s9ou*# not re*- on just one met9o# an# s9ou*# use an- met9o# t9at enab*es an operator to estimate or measure t9e corrosion rate occurrin' in service of an item of p*ant7 or t9e corrosivit- of a process stream. T9e main met9o#s fa** into t9e fo**oin' cate'ories 1. OnB*ine corrosion monitorin' tec9ni@ues to assess corrosion rates an# c9an'es in corrosivitit9 time7 suc9 as e*ectrica* resistance probes7 e*ectroc9emica* probes7 fie*# si'nature monitorin' /)S!7 f*e6ib*e u*trasonic trans#ucer mats /)*e6imats7 bioBprobes an# corrosion coupons. 2. Ana*-sis of process streams for pressure7 temperature7 pro#uction rates7 f*ui# c9emistr-7 CO 2 an# 2S 'as concentrations7 ater content7 #e point7 #isso*ve# o6-'en7 p7 corrosion pro#uct /)e an#or !n concentrations7 bioBactivit-7 c9emica* treatments /e.'. #ose rate7 fre@uenc- an# resi#ua* *eve*s. !onitorin' an# inspection are over*appin' tas:s t9at nee# to be put in p*ace to confirm 1. Actua* versus pre#icte# corrosion rates 2. +rocess parameters are it9in #esi'n *imits 3. Correct operation of contro* measures . Current con#ition of e@uipment !onitorin' encompasses t9e on'oin' monitorin' of t9e corrosion process an# t9e measures ta:en to contro* it7 9ereas inspection provi#es mec9anica* inte'rit- assurance an# #atum points a'ainst 9ic9 corrosion monitorin' can be re*ate#7 ca*ibrate# an# @uantifie#. Inspection tec9ni@ues to assess c9an'es in a** t9ic:ness7 ca*ibrate onB*ine corrosion monitorin' an# #etect materia* #efects7 pittin' an# crac:in'7 inc*u#e u*trasonics /UT7 ra#io'rap9-7 t9ermo'rap9-7 visua* e6amination7 #-eBpenetrant7 e##- current an# ma'netic partic*e inspection. Detai*in' of inspection re@uirements is outsi#e t9e scope of t9is #ocument.

11 .

C o rr os io n ! on i to ri n - Tec )n i +u es a n # *+ u ip m en t

T9e fo**oin' monitorin' tec9ni@ues s9a** be use#. ,9ere corrosion monitorin' is to be performe# at an i#entifie# *ocation7 access fittin's s9ou*# be provi#e# for t9e use of bot9 an %R +robe an# a corrosion coupon.

1 1.  . 1 * % e c t r i ca % R e s i st a n c e 6 * R 8 0 r o b e s •

%R probes s9a** be use# in 9-#rocarbon process environments suc9 as 'as an# con#ensate *ines.

•

)*us9 mounte# %R probes mounte# at t9e  o[c*oc: position mabe use# in seet /i.e. nonB 2S containin' 'asoi*ater environments.

•

Tubu*ar %R probes s9a** be use# if space access prevents t9e *ocation of access fittin's for f*us9 mounte# probes at t9e  o[c*oc: position /or 9ere t9ere are concerns in pro#uce# ater *ines t9at iron su*p9i#e #eposits ma- cause bri#'in' an# crevice corrosion. ,9ere tubu*ar %R probes are use#7 particu*ar*- for 'as circuits an# if mounte# at t9e 12 o[c*oc: position7 t9e- s9a** be of sufficient *en't9 t9at t9e sensitive e*ement is positione# at "mm above t9e bottom of t9e *ine.

+a'e 8

•

+robes s9a** be of t9e retractab*e t-pe7 it9 e*ements manufacture# from stee* of t9e same t-pe as t9e pipin' s-stem bein' monitore#7 rate# for t9e pressure of t9e s-stem bein' monitore#.

•

T9e probes s9a** be supp*ie# comp*ete it9 a probe a#aptor to ma:e cab*e connection to t9e probe.

•

)or eac9 probe supp*ie# an i#entica* probe s9a** be supp*ie# as a spare. A** spare e*ements s9a** be proper*- protecte# in >CI paper to e*iminate corrosion or contamination prior to use.

•

Remote Data Co**ectors /RDCs s9ou*# be use# in remote *ocations an#or in critica* s-stems 9ere *oss of corrosion in9ibition or process contro* cou*# resu*t in rapi# meta* *oss. !easurement fre@uencies s9ou*# be set initia**- at ;Bminute interva*s7 but t9is can be increase# or #ecrease# /#on to "B1" minutes if re@uire# #epen#in' on t9e service e6perience. )or 9i'9*- critica* s-stems7 suc9 as at t9e in*et to t9e !TABTC++ pipe*ine7 t9e use of #ata transmitters *in:e# to t9e TC++ contro* room s9ou*# be consi#ere# in or#er to provi#e au#ib*e an# visua* a*arms an# initiate corrective action if preset G+Is are e6cee#e#.

11. . 2 C ou po ns •

Coupons s9ou*# be insta**e# 9erever %R probes are use# to provi#e supp*ementarinformation7 particu*ar*- for corrosion morp9o*o'- /e.'. pittin'7 erosionerosionBcorrosion. Coupons s9ou*# be remove# at interva*s of 1 to 3 mont9s #epen#in' on t9e corrosivit- of t9e environment an# or t9e *i:e*i9oo# of *oss of in9ibition or process contro*.

•

Coupons mabe strip t-pe7 *a##er t-pe or f*us9 #isc t-pe.

•

,9ere strip t-pe coupons are use# in access fittin's mounte# at t9e 12 o[c*oc: position7 t9e *en't9 of t9e coupon an# coupon 9o*#er s9ou*# be or#ere# suc9 t9at tip of t9e coupon is 9e*# appro6imate*- "mm from t9e pipe bottom.

•

%ac9 coupon 9o*#er s9a** be a retractab*e t-pe an# a**o positionin' of t9e coupons as re@uire# to obtain t9e optimum position at t9e bottom of t9e pipe 9ere t9e corrosive a@ueous p9ase is most *i:e*-. Coupon 9o*#ers s9ou*# be supp*ie# it9out coupons. Strip an# *a##er t-pe coupon 9o*#ers s9a** be capab*e of 9o*#in' tin coupons.

•

%ac9 coupon s9a** be supp*ie# preBei'9e# it9 a seria* number an# t9e ei'9t c*ear*- s9on. )or eac9 coupon 9o*#er7  /four pairs of coupons s9ou*# be supp*ie# to provi#e a minimum of one -ears monitorin'. Coupons s9ou*# be supp*ie# in#ivi#ua**- rappe# an# protecte#.

•

In#ustr- accepte# stan#ar#s for t9e use of coupons coverin' coupon preparation7 c*eanin' an# inspection7 an# reportin' of information inc*u#e a. AST! &

Con#uctin' Corrosion Coupon Tests in +*ant %@uipment

b. AST! &

+ractice for %6amination an# %va*uation of +ittin' Corrosion

c.

+ractice for +reparation of !eta**ur'ica* Specimens

AST! &41

#. AST! &31

(aborator- Immersion corrosion Testin' of !eta*s /covers c*eanin' of coupons

e. NAC% R+ ;88"

+reparation an# Insta**ation of Corrosion Coupons an# Interpretation of Test Data in Oi*fie*# Operations

+a'e 8"

1 1.  . 3 ; a ct e ri a % ! o n i t or i n - a n # ; i o pr o b es In or#er to #etect an# @uantif- t9e propensit- for microbia**- in#uce# corrosion /!IC it is necessar- to @uantif- bot9 t9e p*an:tonic /mobi*e an# sessi*e /surface a#9erin' bacteria in accor#ance it9 A+I R+ 34. =acteria* monitorin' usin' bioprobes i** not be re@uire# for t9e 66 an# 66 pipe*ines7 but p*an:tonic bacteria s9ou*# be assesse# perio#ica**- /e.'.  mont9*- b- removin' a samp*e from t9e respective pi' receivers on 66 after pi''in' operations into a sea*e# stan#ar# seria* #i*ution :it at t9e samp*e site.

11. "

0 roc ess S tr eam ! on it or in-

+rocess stream monitorin' for t9e pro#uction s-stem s9ou*# comprise •

)*o rate /'ascon#ensate

•

Temperature an# pressure

•

CO2 in t9e 'as p9ase

•

,ater c9emistr- an# ironman'anese counts in t9e ater from t9e pipe*ines

•

So*i#s pro#uction

•

+ro#uction c9emica* a##itions /rate an# t-pe an# perio#ic measurement of in9ibitor resi#ua*s

•

+*an:tonic an# sessi*e bacteria monitorin' in t9e ater from t9e pipe*ines

•

Corrosion pro#uct e6amination an# bacteria ana*-sis after c*eanin' pi' runs

•

+rocess stream monitorin' for #e9-#rate# 'as streams s-stems s9ou*# a*so comprise testin' of t9e ater #eBpoint of t9e 'as.

11 .4

C o rr os io n ! o ni t or i n- I ns t ru m en t at i on

,9ere specifie#7 corrosion measurements for %R probes s9ou*# be ta:en b- eit9er 9an#B9e*# portab*e instruments or fi6e# instrumentation7 as fo**os •

+ortab*e instruments use# to ta:e perio#ic rea#in's for temporar- stora'e an# #on*oa# to a persona* computer or *aptop computer. T9is mabe appropriate for %R probes *ocate# at t9e 66p*atform 9ere t9ere i** be sufficient staff to perform t9e re@uire# #uties7 but fi6e# instruments ou*# be more appropriate for an unmanne# e**9ea# p*atform suc9 as 6an# 66+.

•

)i6e# instruments /Data Co**ection Units for continuous monitorin' at re'u*ar interva*s an# t9e stora'e of t9e corrosion #ata to removab*e memor- mo#u*e for subse@uent #on*oa# to a persona* computer or *aptop computer. T9is is 9i'9*- recommen#e# for an unmanne# offs9ore p*atform suc9 as 66 an# 66

+a'e 8

1 2.

C OR RO SI ON DATA ! AN A, *! *N T AN D AS S* SS !* NT

1 2. 1

, ene ra % R e+ ui re me nt s

Data mana'ement is an important part of t9e corrosion mana'ement s-stem. T9e overa** purpose is to maintain recor#s of re*evant #ata for ana*-sis purposes.

1 2. 2

D at a Co %% ec ti on /r e+ ue nc '

Data co**ection i** be #epen#ent on t9e inspection pro'ram #eve*ope# for t9e +anna an# !u:ta assets an# t9e samp*in' rate for t9e process con#itions an# corrosion monitors. It is recommen#e# t9at t9is #ata be store# on a #atabase t9at interfaces it9 t9e p*ant contro* s-stems for operationa* #ata. Corrosion #ata s9ou*# be mana'e# as part of t9e overa** pipe*ine inte'ritmana'ement s-stem.

12.3

Data Stora-e

Data stora'e s9a** be contro**e# in accor#ance it9 t9e @ua*it- assurance re@uirements of t9e operation an# t9e re*evant *e'is*ative re@uirements. !ost #ata i** be e*ectronic an# t9erefore s9ou*# be bac:e#Bup as part of t9e routine #isaster recover- s-stem for t9e operations computer s-stem. A #atabase is recommen#e# for co**atin' inspection an# process #ata as e** as contro**in' 9ar# copinspection recor#s7 p9oto'rap9s an# reports.

12.

Data Assessment

Data assessment s9ou*# inc*u#e t9e revie of process tren#s an# corrosion monitorin' e@uipment resu*ts. In a##ition to t9e operationa* #ata7 an assessment of t9e fie*# inspection an# maintenance performance it9 re'ar# to t9e in9ibitor injection s-stem avai*abi*it- s9ou*# a*so be carrie# out. T9e tren#s an# instantaneous resu*ts s9ou*# be reviee# a'ainst a benc9mar: or G+I for t9e asset. ,9ere a#verse tren#s are startin' to form t9en corrective action nee#s to be put into p*ace b- t9e fie*# corrosioninspection en'ineer in conjunction it9 ot9er #iscip*ines invo*ve# in operatin' t9e assets as appropriate. +roce#ures s9ou*# be #eve*ope# to ensure stan#ar# met9o#s are emp*o-e# t9at are in#ustr- base# an# ensure repeatabi*it-.

12."

C orrosion R eport in-

Corrosion reportin' s9a** inc*u#e a** t9e *atest #ata an# comparisons of t9is #ata it9 t9e 9istorica* #ata. T9e report s9ou*# #etai* t9e current operationa* con#itions if #ifferent from norma*7 if t9ere are an- corrective actions re@uire# an# fo**oBup to corrective actions ma#e previous*-. A stan#ar# report format is recommen#e# to ma:e t9e report easier to rea# b- t9e various en# users an# to a**o repeatabi*it- an# comparison of previous #ata. T9e report s9ou*# 9ave a section for conc*usions an# recommen#ations

+a'e 88

13.

C ORROS ION 0*R /OR !AN C* TR AC KIN ,

1 3. 1

, ene ra % R e+ ui re me nt s

It is important to be ab*e to monitor an# eva*uate t9e performance of t9e corrosion mana'ement s-stem. T9e met9o#o*o'- be*o presents one possib*e eva*uation stan#ar#. T9e process of performance measurement inc*u#es consi#eration of •

Settin' performance measures /:e- performance in#icators /G+I[sH

•

)re@uenc-H an#

•

Corrective Actions.

1 3. 2

K e' 0 er fo rm an ce I n# ic at or s

G+Is ta:e into account five :e- performance areas7 t9ese bein' •

ea*t97 Safet- an# %nvironment G+Is.

•

Operationa* G+Is.

•

=u#'et G+Is.

•

+eop*e G+Is.

•

Transition G+Is.

T9e specific G+Is are uni@ue to eac9 process7 an# are outsi#e t9e scope of t9is #ocument. In particu*ar7 t9e fo**oin' G+Is are recommen#e# •

C9emica* corrosion in9ibitor s-stem avai*abi*it-7 tar'et 54.

•

OffBspecification 'as *ift 'as /i.e. et7 tar'et M ; #a-s per annum.

•

Sca*e in9ibitor s-stem avai*abi*it-7 tar'et 55

•

San# #etection measurement an# s-stem avai*abi*it-7 tar'et 55.

•

+ipe*ine corrosion monitorin' avai*abi*it- an# temperature an# corrosion rate corre*ations to pre#ictions7 tar'et 55.

•

+i' run p*an performance7 p*annin' an# ana*-sis7 tar'et p*an comp*etion inc*u#in' ana*-sis it9in  ee:s of p*anne# activit-.

•

+rocess samp*e monitorin' an# ana*-sis /inc*u#in' 'as7 *i@ui# an# so*i#s samp*e ana*-sis7 tar'et ana*-sis an# reportin' it9in 1 ee: of p*anne# activit-.

T-pica**-7 t9e G+I[s s9a** be use# to report a'ainst #urin' t9e @uarter*- an# annua* reportin' to !ana'ement.

1 3. 3

C or re ct i ve a n# 0 r eve nt at ive Ac t io n

Substan#ar# performance s9a** be investi'ate# an# reporte# if improvements are to be ma#e an# mista:es e*iminate#. It s9a** fo**o t9e forma* Tec9nica* C9an'e !ana'ement processes.

+a'e 84

,9ere G+I[s 9ave not been ac9ieve# it is important t9at t9e cause/s are i#entifie# an# t9at annecessar- measures to ensure t9at t9e s-stem can be improve# are imp*emente#. It is t9e constant reBe6amination an# incorporation of *essons *earnt t9at *ea#s to improvement of an- inte'ritmana'ement s-stem.

+a'e 85

1.

R*/*R*NC*S

6

+a'e 4;

Appen#i( 1 H Temperature an# 0ressure 0rofi%es /1 +a'e

Appen#i6

Appen#i( 2H Corrosion !o#e% Resu%ts

Appen#i6

62 ( A3 0a-es8

Appen#i( 3H ist of Unin)ibite# *vents

Appen#i6

62 0a-es8

UNIN
A *istin' of potentia* unin9ibite# events t9at s9ou*# be consi#ere# is 'iven in t9e tab*e be*o. T9is is not an e69austive *istH ot9er event maoccur in specific insta**ations. Tab%e 1L

Unin)ibite# *vents

*vent

Detection s'stem

Contro% s'stem options

Incorrect in9ibitor arrives at site

+9-sica* tests on in9ibitor 9en it arrives on site.

?C s-stem on in9ibitor supp*-

In9ibitor formu*ation c9an'e# b- supp*ier /or t9eir supp*iers Supp*- mi6 up from supp*- base

Comment Impact

+robab*- #etectab*e b- in9ibitor resi#ua*s

Interference in supp*In9ibitor runs out at t9e e**site #ue to ina#e@uate stoc: *eve*s on site or supp*base

!onitorin' amounts use# an# cross c9ec:in'

Stoc: contro* s-stem

G+Is

Automatic *eve* 'au'es Tie in to contro* room a*arms

,ron' in9ibitor *oa#e# into tan: boperators

+robab*- #etectab*e b- in9ibitor resi#ua*s

Trainin' an# +roce#ures

G+Is

In9ibitor tan: a**oe# to run empt-

In9ibitor returns


G+Is

Tie in to contro* room a*arms In9ibitor incorrect*- #i*ute#



In9ibitor +ump =rea:#on

In9ibitor returns

!anua* c9ec:in' )*ometers

+oer fai*ure to pump7 it9 pro#uction sti** continuin'

+ump cou*# be a*arme#

!anua* c9ec:in'

In9ibitor returns

)*ometers

+a'e 1

=ac:up pump options /none7 avai*ab*e in store7 avai*ab*e on site7 automatica**sitc9e# over )ina* option is to s9ut #on pro#uction

*vent

Detection s'stem

Contro% s'stem options

Comment Impact

+oer fai*ure to pump7 it9 9ic9 a*so stops pro#uction

+ump cou*# be a*arme#

!anua* c9ec:in'

!a- 9ave *itt*e or no impact /#epen#s on corrosion rate an# in9ibitor persistenc- in nonBf*oin' con#itions

)*ometers

In9ibitor #e*iver- from tan: to injection *ocation fai*s /*ine b*oc:a'e7 fai*ure

In9ibitor returns

)*ometers

In9ibitor se*ection re*ate#. Use portafee# t-pe tan:s /c*eane# re'u*ar*-7 rat9er t9an permanent tan:s 9ic9 mabui*# up #eposits

Injection rate incorrect*- set



Operatin' con#itions c9an'e7 re@uirin' a c9an'e of injection rate 9ic9 is not carrie# out


+i''in' re@uire# for #istribution of in9ibitor an# not carrie# out.


O6-'en a**oe# to enter t9e s-stemH corrosion in9ibitor ineffective a'ainst O6-'en corrosion =acteria a**oe# to enter t9e s-stemH corrosion in9ibitor ineffective a'ainst !icrobio*o'ica**- in#uce# corrosion

G+I

Cu*tures from ater samp*es

Operatin' environment c9an'es an# in9ibitor becomes tota**- ineffective

G+I

rep*acement in9ibitor 9as to be se*ecte#

+a'e 2

Appen#i( H C)emica% Datas)eets 6" pa-es8

Appen#i6

A Typical Material Selection Report

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