6 - Nitrogen Pumping

INTRODUCTION TO NITROGEN PUMPING Nitrogen Pumping

Italfluid Egypt Confidential

Overview • Nitrogen caracteri!tic! • Nitrogen pumping unit " Operating in!truction! and main component! " Operation! #Tan$! filling% &!!em'ly &!!em'ly and and Te!t!% Cool"down% Pumping(

• Main application! in oilfield) " Pre!!uri*ation!% Replacement+Purging% Ga! lift

Nitrogen Pumping


Overview • Nitrogen caracteri!tic! • Nitrogen pumping unit " Operating in!truction! and main component! " Operation! #Tan$! filling% &!!em'ly &!!em'ly and and Te!t!% Cool"down% Pumping(

• Main application! in oilfield) " Pre!!uri*ation!% Replacement+Purging% Ga! lift

Nitrogen Pumping


Nitrogen caracteri!tic! Nitrogen) odourless,

colourless, and inert gas, present in nature at elementary state; indeed it constitutes 78% of the earth atmosphere in wich molecule N 2 can be found. Chemical symbol

N

tomic number

7

tomic weight

!",##7

$usion temperature

2!#& C

'oilling temperature

!()& C

*as density

!,2+! g-m

/i0uid density

8#8,2 g-m

Critical temperature

!2),!& 1!"7,!&C

Critical pressure

",) bar

Nitrogen Pumping


Nitrogen caracteri!tic! •

3ndustrially, nitrogen is prepared through fractioned distillation of li0uid air

•

4n the mar5et, nitrogen can be found in6  *aseous state, stored inside gascylinders with pressure of !+#2## bar  /i0uid state, stored in boiling state, inside special thermal insulated tan5s at !()&C with pressure of  bar

Nitrogen Pumping


Nitrogen pumping unit Operating in!truction! and main component

Pipe! and component! component! Nitrogen Tan$

Nitrogen Pump

Nitrogen Pumping


Nitrogen pump


Nitrogen pump

Main component!)

• ngine -
Cryogenic unit which pumps li0uid nitrogen at ery low temperature 1!()&C and pressures up to !#### psi, and coerts it into a gas 1ma9 7#&C by means of apori:er

 /i0uid nitrogen suction line system  s return line system

•
• 3nta5e manifold section

1high pressure line system

 /i0uid nitrogen high pressure line system  @apori:er  *aseous nitrogen high pressure line system

• Coolant circuit 1water bra5e Nitrogen Pumping


Nitrogen pump


Nitrogen Pumping


Nitrogen pump


Engine / Transmission • 3t supplies the necessary power for the moement of the triple9 pump, and to carry out additional functions • 3t is directly connected to the waterbrake and different hydraulic pumps • Aydraulic pumps supply power to the hydraulic engines of the circuits of the triple9 pump, centrifugal pump, coolant and lubrication • 3t is e0uipped with air startup •

Nitrogen pump


Return and suction manifold section (Low pressure line system)

,i-uid nitrogen !uction line !y!tem) • 3t is connected to the inta5e line of the nitrogen tan5 through cryogenic fle9ible pipes • 3t supplies li0uid nitrogen to the triple9 pump with a pressure of "#!## psi •  centrifugal pump 1boost pump is installed on the line, in order to bring the li0uid nitrogen from the pressure outgoing from the tan5 1generally !#2# psi to that entering the triple9 pump 1"#!## psi • Nitrogen pumps are usually e0uipped with a bypass line of the boost pump •  line is present at the outlet side of the centrifugal pump 1centrifugal pumps recirculation which bypasses the triple9 pump for the recirculation of the li0uid nitrogen inside the tan5 during the cooldown phase Nitrogen Pumping


Nitrogen pump


Return and suction manifold section (Low pressure line system)

Tan$.! return line !y!tem) • 3t is connected to the nitrogen tan5>s return line through cryogenic fle9ible pipes

• 3t allows the return of nonpumped li0uid nitrogen inside the tan5

•  0uic5 cooldown line is installed on the line to fill the pump

•  line is installed on the outlet of triple9 pump for the recirculation of li0uid nitrogen during cooldown phase Nitrogen Pumping


Nitrogen pump


Tri plex pump section Triplex • 3t is a piston pump, whose tas5 is to increase the pressure of li0uid nitrogen until a ma9imum operating pressure of !#### psi • 3t is enabled through the hydraulic transmission6 the diesel engine enables a pump with ariable displacement which conoys the oil under pressure to the engine with fi9ed displacement •
Cold end!)

/arm end!)

3t is the section that guides the cold end


Nitrogen pump


Intake manifold section (Hig pressure line system) 3t is constituted by lines outgoing from the triple9 pump>s cold ends 1inta5e lines 3t is made up by the following parts6

0apori*er ,i-uid nitrogen ig pre!!ure line !y!tem 3t is the line section that connects the cold ends to the apori:er; the nitrogen that flows inside is pressuri:ed but still at li0uid state

Nitrogen Pumping

Ga!eou! nitrogen ig pre!!ure line !y!tem 3t is that line section outgoing from the apori:er; the nitrogen that flows is pressuri:ed and at gaseous state, ready to be pumped; a plug ale 1hydraulically actuated is installed at the end of this line

3t is a particular heat e9changer, constituted by a cylindrical chamber filled up by a pipe bundle inside of which li0uid nitrogen flows.

Nitrogen pump


Intake manifold section (Hig pressure line system) • s circuit is controlled manually to 5eep the apori:er>s temperature constant between !## and !2#&$ 18"(&C. • outlet which allows the li0uid nitrogen, by opening a proper ale 1tempering valve, valve to bypass the apori:er and conoy li0uid nitrogen inside the line 1to use only in case of e9treme need to rapidly cool the out flowing nitrogen • nother line, always mounted at the outlet of the cool ends, allows to recirculate the li0uid nitrogen inside the tan5s by opening a specific ale prime 1 prime valve valve during the cooldown operation Nitrogen Pumping


Nitrogen pump


Nitrogen Pumping


Nitrogen pump


!oolant circuit 3t is a waterglycol recirculation system that supplies 1through thermal e9change with the apori:er the heat needed to cause the eaporation of the li0uid nitrogen.
1ydraulic circuit /ater'ra$e 3t is a hydraulic bra5e assembled on an a9is of the engine>s power ta5eoff. 'y sending li0uid to the waterbra5e, the engine goes under load, and in this way, the engine>s power is conerted in heat.

,u'rication Engine.! cooling circuit circuit! of
Nitrogen Pumping

the engine>s operating temperature so as to 5eep it constant within a range of )#7#&C.


Nitrogen pump

Nitrogen pumping unit Operating in!truction! and main component ! =egistratore a carta 2
!ontrol panel !ontrol panel

2"

2

! 22

2! 2

!7

2)

2# !(



!8

"

!)

+

Nitrogen Pumping

2+

)

7

8

(

!# !! !2


!

!"

!+

Nitrogen pump


Nitrogen Pumping


Nitrogen pump


Nitrogen pumping lines !  GHNB4B<=>D E=DDI= @/@6 3t regulates the pressure of the li0uid flowing to the waterbra5e

4

2  @E4=3J=>D 'HEDD @/@ (TEMPERING VALVE): 3t opens the apori:er>s bypass ale 1N.'.6 this manoeure can considerably and dangerously cool down the outgoing nitrogen>s temperature.

6 5 =

  A3*A E=DDI= N3<=4*N =C3=CI/<34N @/@ (PRIME VALVE): 3t opens the recirculation line, from the cold ends outlets to the tan5s return line "  N3<=4*N =C3=CI/<34N @/@

8

<

;

+  N3<=4*N <N =
4:

7

8  KI3C C44/G4?N @/@ (  N3<=4*N 3N< @/@

9

!#  '44D< EIBE 'HEDD @/@ !!  '44D< EIBE

44

!2  @E4=3J= !  E/I* @/@ AHG=I/3C C
Nitrogen Pumping


46 45

Nitrogen pump


Nitrogen Pumping


Nitrogen tank


Nit rogen tank Nitrogen •
Nitrogen Pumping


Nitrogen tank


Nitrogen Pumping


Nitrogen tank

Nitrogen pumping unit Operating in!truction! and main component !  /@/ 3NG3C<4=6 3t indicates the leel of the li0uid nitrogen inside the tan5 2  E=DDI= *I* : 3t indicates the tan5>s internal pressure   *D4ID EAD @/@6 3t opens the inlet of the differentialmeter connected to the gaseous phase "  /3KI3G EAD @/@6 3t opens the inlet of the differentialmeter connected to the li0uid phase +  KI/3J= @/@6 3t connects the Mli0uid phase ale and the gaseous phase ale )  @CIIB '= G3DC6 Gisc located on the tan5>s e9terior surface and 5ept in position by the acuum inside the interspace of the same tan5 7  @CIIB EIBE>D $3<<3N* 8  D$
Nit rogen tank Nitrogen (!omponents) ;

5 < =

!#  =/3$ LC/ID34N @/@ 3t stops the e9haust of pressure through a relief ale 6 !!  '/G4$$ @/@ ale used to manually e9haust the internal pressure !2  4@= $/4? @/@ 3t must always be 5ept open during fill up operations. it indicates the filling up leel of about 8#% of tan5 when the li0uid oerflows !  CAC @/@

Nitrogen Pumping

8

7


8

9 4:

46 45

44

Nitrogen tank

Nitrogen pumping unit Operating in!truction! and main component !"  $3/<=

Nit rogen tank Nitrogen (!omponents)

!+  3N< @/@ !)  =s return line that must be 5ept open during operations

;

8

7

8

9 4:

!7  3N< DAI<4$$ @/@6 @ale on the pump>s inta5e line that must be 5ept open during operations !8  D$
5

!(  == $3//3N* @/@6 @ale for the shutoff of the rear tan5>s filling line

<

4

2#  G=3N3N* @/@6 @ale that allows to e9haust the line>s pressure prior to remoe the fle9ible grinding wheel.

=

46 45 47 48

6

2!  E=DDI=3J<34N @/@6 @ale that, once open, conoys li0uid nitrogen to the apori:er

6:

22  @E4=3J=

Nitrogen Pumping


4;

48 4=

4<

49

64

66

44

"ipes and !omponents


"i pes and components "ipes • Eumping line>s components 1pup oints, ales, tee, elbows, crossoer, etc. must be manufactured for !#### psi w.p., and they must hae Mweco fig. !+#2O connections • Eumping line>s connections must be welded or integrated 1threaded connections don>t admit • /ow pressure fle9ible pipes 1suction and return lines must be cryogenic and e0uipped with C* !O!-2 connections
N# $ "lug %al%es&

N# ' !eck %al%e

!  3mmediately after the pump 2  t the end of line

Nitrogen Pumping


N# ' leedoff %al%e

Nitrogen pumping unit Operation! • Tanks filling& $illing operation is different depending on tan5>s temperature 1tan5 is McoldO if it contains li0uid nitrogen, instead tan5 is MhotO if it is empty • *ssem+l y and test& *ssem+ly Eressure test must be performed with fresh water. 3n case of absence of triple9 li0uid pump, fill the line with fresh water and pressuri:e with nitrogen • !ooldown& s components in which li0uid nitrogen will flow, and to faour the filling of boostpump>s inta5e lines • "um ping& "umping& 3t is forbidden to e9ceed operatie parameters

Nitrogen Pumping


Main application! in oilfield
• -as lift Nitrogen is pumped in the well through C< or production tubing, to ma5e easier the spontaneous well production, lightening the li0uid column in the well

• "ressuri,ation Eressuri:ations with nitrogen can be re0uested for different operations, such as stuffing due to change of leer or shots, fi9ing of pac5ers, rebalancing of pressures aboe and below a ale prior to anticreep leelling it, etc... Erior to start pumping, ma5e sure that pressure is present inside the well and as a conse0uence, apply the same pressure on the treatment line prior to open the ales

• Re placement / "urging Replacement Nitrogen can be pumped in pipelines and tan5s that contained corrosie or inflammable li0uids, to restore inert atmosphere

• *cidi,i ng / .racturing *cidi,ing Nitrogen is pumped in the well to s0uee:e acid. fter the reaction between acid and formation, nitrogen ma5es easier the reaction>s fill remoal Nitrogen Pumping


Main application! in oilfield Computation criterion

"ressuri,ations / R eplacement Replacement !. 2.

3dentify the olume to pressuri:e or relocate 4nce the final pressuri:ation-replacement pressure is 5nown 1at the head or bottom of the well, calculate the aerage end replacement-pressuri:ation pressure6 1'AEP?AE-2.
Nitrogen Pumping



"ressuri,ations / R eplacement Replacement .

Calculate the aerage temperature6 1'A
".

'y using the specific tables of the ?ellsite manual 1MBQ of nitrogen per BQ of spaceO or Mscf of nitrogen per barrel of spaceO according to the units of measurement used, intersecting the ust calculated column of the aerage temperature with the aerage pressure line, it is possible to obtain the olume factor

+.

Calculate the 0uantity of nitrogen re0uired for the specific wor5, multiplying the olume factor by the olume calculated in point !

).

4nce the pumping flowrate has been defined, calculate the time need for pressuri:ation, by diiding the 0uantity of nitrogen calculated in point + by the same flowrate

Nitrogen Pumping



"ressuri,ations / R eplacement Replacement N&
I0"1RT*NT& 3n I0"1RT*NT& case the string or pipe has already an initial pressure, calculate the relatie 0uantity of nitrogen 1using the aboe procedure and subtract it to the one calculated in point +

Nitrogen Pumping


E>EMP,E? E2emple 4) "ressuri,ation of a surface pipe The fllwing e!ample "an be applie# fr hri$ntal (r "hara"teri$e# b% &mall in"linatin #ifferen"e&) pipeline' it i& the "a&e fr e!ample f "ile# tbing n reel& t #i&pla"e an# p&&ibl% pre&&ri$e after the h%#rali" te&ting pha&e an# prir t #e&"en# int the well /et>s consider a hori:ontal pipe closed at the two edges, whose characteristics are6 3nternal diameter R 8O /ength R 2# 5m
2uestions& !. 2.

Aow much nitrogen is re0uired to pressuri:e the pipe up to !7+# psiS Aow much time do 3 need to perform the operation, assuming to pump a constant output of !### scf-minS

Nitrogen Pumping


E>EMP,E? E2emple 4) "ressuri,ation of a surface pipe *nswers& !.

s section #."(#" 1ft2 9 )+)!7 1ft R 22(# ftQ 1pipe>s olume 22(# 1ftQ 9 #,!78!! 1conersion factor ft-bbl R "#7(. bbl Considering that the pipe is hori:ontal, the aerage end replacement-pressuri:ation pressure is e9actly !7+# psi. fter calculating the olume in barrels, let>s loo5 at the table of the ?ellsite Banual that indicates the olume factor in scf per barrel of space. 3n our case, at the intersection of line !7+# psi with the column indicated with 2#&C, we find the alue6 )7#

2.

)7# 9 "#7(. 1bbl R 6755454 !cf 1remember to consider the !#### scf needed for the pump>s cool down
Nitrogen Pumping


E>EMP,E? E2emple 6) "ressuri,ation of a surface pipe /et>s consider the same pipe of the preious e9ample, but let>s assume that is initially pressuri:ed with nitrogen at !### psi and that there are !### bbl of water at its interior.

2uestions& !. Aow much nitrogen is re0uired to pressuri:e the pipe up at !7+# psiS 2. Aow much time do 3 need to perform the operation, assuming to pump a capacity of 2###scf-min for the first " hours and !### scf-min for the remaining timeS

Nitrogen Pumping


E>EMP,E? E2emple 6) "ressuri,ation of a surface pipe *nswers& !.

s loo5 at the table of the ?ellsite Banual that indicates the olume factor in scf per barrel of space. 3n our case, at the intersection of line !7+# psi with the column
Nitrogen Pumping


E>EMP,E? E2emple 5) Replacement of te fluid +eing formed The fllwing e!ample "n"ern& the repla"ement f a "lmn f lii# being frme#* &ing nitrgen' thi& &itatin "an ""r in "a&e f treatment in matri! (e+g+ a"i#ifi"atin) with bll,hea#ing pmping r an%hw t re,&tart a well* b% filling the nitrgen "lmn t #e"rea&e h%#r&tati"&+ /et>s consider a ertical well, constituted as shown in the figure
Casing R 7O , 2( lb-ft

Eac5er R 2+## m

'AE R 2## psi at 2)## m

?A< R 2#& C

'A< R !"#& C

2uestion& Aow much nitrogen is re0uired to relocate the fluid contained in the well through shotsS Nitrogen Pumping


E>EMP,E? E2emple 5) Replacement of te fluid +eing formed *nswer& Dince up to 2)## metres must be relocated 1top of shots, the olume to consider is gien by the sum of the tubing>s capacity plus the casing olume from the pac5er to the top of perforations6 V 8.2( 9 2+## 9 .28#8" - !### R )7.(( bbl 1tubing>s internal olume V 7.!"8 9 12)##2+## 9 .28#8" - !### R !2.!( bbl 1casings internal olume
Nitrogen Pumping


6 - Nitrogen Pumping

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