Introduction to Cement Laboratory Testing

Cement Lab Introduction Schlumberger Private

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Schlumberger Private

© Schlumberger 2008

Revision History Description

Reviewed /Prepared by

1.0

Introduction to Laboratory Testing

Deepak Khatri/Jan Liu

May 15, 2009


Rev. Date

Learning Objectives


• Laboratory Functions • Key Slurry properties and the testing in the laboratory • Laboratory testing standards & procedures • Interpretation of laboratory reports & charts for the actual job • Equipment used in the laboratory • Use the Laboratory video as applicable for the Operational school

Laboratory Functions Performance Testing Design Stage – Measurement of slurry properties under downhole conditions.

Execution Stage – Control the quality of the blended material

Evaluation Stage – Investigation of job failure

Analytical Testing Quality control of the slurry components prior to mixing. – Cement – Additives – Mix Water


Analytical Testing Four types of samples are examined; Cement Powder Chemical Analysis: C3A, C3S, C2S, C4AF and Gypsum Dry Blended Cement

XRD, FTIR, microscopic Mix water

Ionic content: – Sulphates, chlorides, hardness


XRD, FTIR Set Cement

Performance Testing- Slurries Governed by the API committee on “Standardization of Oilwell Cements” (Com. 10) & ISO Publication consists of; Specification tests for neat cement slurries (API Spec 10A or ISO 10426-1)

Operational testing procedures for all slurries (API RP10B-2 or ISO 10426-2 and others) Procedures designed to simulate downhole conditions

Pressure

Temperature


Performance Testing-Spacers/Washes Evaluation of the cleaning effect Compatibility with Cement Thickening Time

Fluid Loss

Compressive Strength

Rheology … Compatibility with mud

Rheology etc.


Compatibility Testing FORMULA: (Highest Reading of fluid combinations) – (Highest reading of individual fluids)

Fluid combinations: <0

Compatible

95:5

0-40

Possibly incompatible

75:25

40-70

Slightly incompatible

50:50

70-110

Definitely incompatible

>110

Severely incompatible

25:75 5:95 100%


100%

Sample Preparation


Sample Preparation

Prior to shipment No additive should be used that is not from actual field samples Sample and handling procedures

API Spec 10 - Section 3 Echoes the requirements of the ‘KSQR’


Use representative samples. Sample acquisition

Slurry Design


Slurry Properties Free Fluid & Slurry Sedimentation Water separation from static slurry

Migrates upward, accumulates in pockets or at top of cement column.

Varying density gradients in the cement column

Results in unstable slurries, annular bridging, incomplete zonal isolation Density

Balance sub-surface pressures

Sample Number Top 1 2 3 4 5 6 7 Bottom 8

Weight of Sample (g) 18.11 14.81 14.72 16.73 14.36 16.4 16.01 19.04

Weight of Volume of Removed Water (g) 14.01 11.39 11.33 12.81 10.94 12.56 12.34 14.37 Average Density:

S.G. of Slurry 3 (g/cm) 1.26 1.26 1.26 1.27 1.28 1.27 1.26 1.29

Density of Slurry (ppg) 10.49 10.55 10.54 10.60 10.65 10.59 10.53 10.75

1.27

10.59


Slurry Properties - cont. Pumpability (Slurry Consistency) Length of time slurry remains in a pumpable fluid state (Job Time + 2 hr or Job Time x 1.5 hr, whichever is higher)

Instrument: 940 Left 940 L Test Start: 1/10/2008 2:25:18 PM Well ID CCS08002-1R-D186-Exp Test Stop: 1/10/2008 6:02:18 PM Customer SLB Comments: Retest of Exp D186 at 16.40 ppg 1500 psi and 65 F (room temp.).

100

90

80

4

40

Pressure (kpsi)

3

2

50

40

30

1

10

0

60


Bearden Consistency (Bc) Fluid Loss

20

Consistency (Bc)

70

60

30

Slurry dehydration during placement phase Rheology

80

70

50

30 Bc @ 2:01:05 70 Bc @ 3:01:05 100 Bc @ 3:36:50

100

5

90

Temperature (°F)

20

10

0

0 0:00

0:30

Schlumberger

1:00

1:30

2:00 Time (HH:MM)

2:30

3:00

3:30

Test File Name: 940 L-CCS08002-1R.tst

4:00

Page 1

70 60 50 Shear Stress (Pa) 30 40

Mixability at surface

20

10

Slurry flow modeling

0

C e m e n t - S h e a r S tr e s s V s S h e a r R a te @ T e m p e r a tu r e : 2 7 d e g C L a b . d a ta B in g h a m p la s tic m o d e l H e r s c h e l B u lk le y m o d e l Po w e r la w m o d e l

0

50

100

150

200

250 300 350 S h e a r R a te ( 1 /s )

400

450

500

550

600

Set Cement Properties - I Compressive strength Tensile strength Schlumberger Private

Young’s Modulus Poisson’s ratio Shear Bond

Cement - Casing & Cement - Formation

F

Set Cement Properties - II Sulfate Resistance

Reaction to magnesium and sodium sulfates;

Strength Retrogression Cement CSH Gel Breakdown begin at >230o F. Permeability

Lightweight slurries


– Loss of compressive strength – Stress cracking

Testing Process LAB ANALYSIS REQUEST SLURRY DENSITY FLUID LOSS TEST

RHEOLOGY CEMENT - SPACER - MUD COMPATABILITY

COMPRESSIVE STRENGTH TEST

THICKENING TIME TEST LABORATORY REPORT


FREE FLUID TEST

Laboratory Procedures & Equipment


Laboratory Analysis Request - (LAR)


Submitted to lab requesting formulation of cement slurry Designate additives available for slurry Request specific performance parameters; Density Rheology ( Plastic Viscosity & Yield Point) Fluid Loss Thickening Time Free Water Provide information on well parameters Job Type, Depth, BHT & mix water type etc.

Sample Calculation Sample volume for slurry testing is 600 ml Consider the following slurry composed of;

Class G Cement & 44% water

Class G Cement

Weight (lbs) 94

Absolute Volume (gal) 0.0382

Volume (gal) 3.59

Weight (gram) 42637.7

Volume (ml) 13589.6

Water 44%

41.36

0.1202

4.97

18760.6

18813.5

TOTAL

135.36

8.56

61398.3

32403.1

Calculate for 600 ml ratio equal to Total Volume / 600 ml ratio = 54:1 Use LabDB or SlurryDesigner for calculations


Material

Constant Speed Blender


Slurry Preparation (API RP10B-2 section 6) Mixed with a high shear mixer (Warring Blender) Two rotational speeds – 4000 rpm – 12000 rpm Water and Liquid Additives weighed out and added first Add Cement /Solids at 4000 rpm (15 seconds) 12,000 rpm for remaining 35 seconds Mixing procedure not suitable for;

Microspheres (D124)

Nitrogen (Foam slurries)


Slurry Tests Density Measurement (API RP10B-2 section 6)

Measured with an Atmospheric or Pressurized Balance

Slurry placed in 250ml graduated glass test tube

Free water (ml) measured after 2 hours

Slurry sedimentation also checked


units are ppg, Kg/m3, SG, and so on Free Fluid Test (API RP10B-2 sect. 15)

Static and Stirred Fluid Loss Apparatus


Fluid Loss Test (API RP10B-2, section 10) Simulates amount of filtrate lost under pressure against a permeable formation Two types of filter press available; Low pressure (100 psi) – for DF only

HPHT, high pressure, high temperature (1000 psi) HPHT is used for slurry test (simulates conditions) Permeable formation simulated by 325 mesh screen

Backed up by a 60 mesh screen Test Parameters – 30 minute static test Reporting


Filtrate Loss

F 30 = 2 x Ft ×

30 t

F30 = Filtrate at 30 minutes Ft = Filtrate at Time t = Time in minutes

If slurry does not dehydrate in 30 min, then API Fluid Loss is: F 30 = 2 x Ft


For slurries that dehydrate in less than 30 minutes, API Fluid Loss value is obtained by either:

Rotational Viscometer (FANN/CHAN 35)


Rheology (API RP10B-2, sect. 12) Calculated by correlation of shear stress against shear rate Tested with Rotational Viscometer (CHAN/FANN 35) Rotational speed (Shear rate) – – – – – – –

300 rpm 200 rpm 100 rpm 60 rpm 30 rpm 6 rpm 3 rpm

Approximation: Pv=(θ300 – θ100) x 1.5 Τy= θ300 – Pv Use LabDB to calculate Pv and Ty!

600 rpm not used to calculate Pv and Ty


Rheology (API RP10B-2, sect. 12) 6 rpm and 3 rpm readings needed for HB rheology 3 rpm reading is used to determine the fluid gel strength at; 10 seconds & 10 minutes BOB (Stationary) Rotational Speed (rpm)

Ramp-up

Ramp-down

Ratio

Average

3

21

24

0.87

22.5

6

40

36

1.11

38

30

65

83

0.78

74

60

84

100

0.84

92

100

100

115

0.87

107.5

200

137

147

0.93

142

300

170

Initial slurry temperature –

Rotational Sleeve

170 150 o F

Final slurry temperature – 146 o F Rheological properties reported at average temperature – 148 o F

Slurry Cup


Atmospheric Consistometer


Pressurized Consistometer


Thickening Time Test (API RP10B-2, sect. 9) Determine length of time a slurry remains fluid Pressurized consistometer simulates both;

Temperature Pressure

Casing (1g - 11g) Liners (22 - 32) Squeeze cementing (12 - 21)

Refer to In-Touch ID is 4718717 for Laboratory Request Checklist


Reported in Bearden units of consistency (Bc) Upper fluid limit: 70 Bc to 100 BC API RP10B-schedules

API Schedules


Pressure and Temperature changes Effect on Thickening Time Realistic Laboratory Evaluation Computer Simulation (CemCADE) New Instrumentation 210

D e p th = 1 2 4 0 7 ft

180 170 160

130

140

150

Temp. History (degF)

190

200

A PI B H CT G e o t h . P r o f ile A n n u lu s

0

10

20

30

40 50 T im e (m in )

60

70

80

90

Thickening Time Test Curves Temperature

100 200 300 400 500

Instrument: 940 Left 940 L Test Start: 1/10/2008 2:25:18 PM Well ID CCS08002-1R-D186-Exp Test Stop: 1/10/2008 6:02:18 PM Customer SLB Comments: Retest of Exp D186 at 16.40 ppg 1500 psi and 65 F (room temp.).

5

100

Bc

100

90

90

4

80

80

3

60

50

40

Pressure (kpsi)

Temperature (°F)

70

2

30

20

Bc

50

100

60

50

40

30

1

10

0

Consistency (Bc)

70

Temp.

30 Bc @ 2:01:05 70 Bc @ 3:01:05 100 Bc @ 3:36:50


Time (min)

deg.F

0 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0

20

10

0

0 0:00

Schlumberger

0:30

1:00

1:30

2:00 Time (HH:MM)

Test File Name: 940 L-CCS08002-1R.tst

2:30

3:00

3:30

4:00

Page 1

Pressurized Curing Chamber


Compressive strength (API RP10B-2, sect. 7) Set cement strength under downhole conditions Apparatus; Curing Bath (ATM pressure & 82oC)

Curing Chamber (3000 psi & 193oC) Procedure. Measurement Unit Other methods


High Temperature High Pressure Testing Ultrasonic Cement Analyzer (UCA)


Non-destructive sonic testing (API RP10B-2, sect. 8) Follow manufacturers operating instructions Remove air before filling cell Set pump to pressure simulating well Select proper correlation (A, B, C) - correlations don’t apply for slurries like LiteCRETE, FlexSTONE, etc. Correlation is to cubes and has inherent error Facing specimens and crushing will give different results than cubes (do not report as API strength)


Proper filling cell

UCA Chart


Laboratory Analysis Report

Well Information

Slurry Design

Lab Test results

Comments

Charts (TT, UCA)


At the conclusion of Cement Slurry formulation and subsequent testing a report is produced outlining the following;

Summary of Test Procedures Test Category

Equipment

Procedure Reference

Sampling

Diverted Flow sampler

API RP 10B-2 – Section 4

Slurry Preparation

Two speed mixer


Thickening Time

Pressurized consistometer HPHP fluid loss cell



Free Fluid

Water bath, curing chamber Hydraulic press 250 ml graduated cylinder

Permeability

Water permeameter


Rheology

Rotational viscometer


Static gel strength

SGSA or Vane rheometer

ISO 10426-6

Expansion & shrinkage

Annular sleeve

API RP 10B-5

Fluid Loss Compressive Strength


Spacer/Wash/Cement Compatibility Rotational viscometer Reverse Emulsion Tester Coupons, grid Sedimentation test Foam cement Closed mixer cup

API RP 10B-2 – Section 15 API RP10B-4

Specification for Cements

API Spec 10A

Various

API RP 10B-2 – Section 16 CEM- Section 2B5

Note: API RP10B-2 = ISO 10426-2 Also CEM- Section 6 lists all Schlumberger cement test procedures




Other Equipments and Tests

Blend specific gravity measurement – Gas Pycnometer Schlumberger Private

Spacer Surfactant Selection Testing Coupon Test

Grid Test

Reverse Emulsion Test


Foam Cement Mixing & Foam cement Generator under pressure Schlumberger Private

SGSA &Vane Gel Strength Rheometer


Cement Hydration Analyzer


Mechanical Properties Testing


HT-HP Rotational Rheometer


Introduction to Cement Laboratory Testing

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