Dynamic Settling/Stability Workgroup – Summer 2013

Robert Beirute, Beirute Consulting; Heath Williams, Schlumberger; Paul Sonnier and Jeff Watters, CSI, Deryck Williams, ChevronTexaco; Greg Garrison and Katrina Price, OTC; Graeme Anthony, OFIte

June 25th, Houston, TX

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Agenda

1. Minutes of Previous Meeting and Action Items

2. Overview of Workgroup objectives/progress

3. Procedures to run dynamic vs. static testing for Workgroup

4. Summary of API Cooperative test results

5. Our roadmap moving forward

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Minutes of Previous Meeting

TG on Test Methods for Determination of Dynamic Settling• Several task group members were present.• Meeting Minutes for January 22nd, 1:15pm held at the Intercontinental New Orleans, LA• Review of testing conducted so far which included a hematite system that failed both the dynamic

settling and free fluid testing, and the spacer system which passed both the dynamic and free fluid test.• A system that passed both free fluid and DST• A system that will pass the free fluid but fail the DST is still being designed• The chairman made the comment that static settling has the potential to develop gel strengths which

can aid in stability whereas dynamic settling does not allow for development of the gel strength.Action Items• After much discussion it was decided to pursue the development of Designs 1 and 2• Continue the round robin testing for the next meeting in the summer.• Designing system for round robin testing that passes static criteria and fails dynamic criteria• Updating the procedure to include the syringe method for taking the density readings of top, middle and

bottom.• Update the procedure to include the weighing of the paddle before and after the test.

Indicates Action Items that have been completed

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Completion/Progress and Projected Timeline

Explored DST alternatives

Phase 1 – showed systems that passed/failed Static and DST

Phase 2 – cement failed DST but passed static

Phase 3 - Submit report/procedures for comments and review from DST Workgroup

01-2012 06-2012 01-2013 06-2013 01-2014 06-201406-2011

Phase 2 – Updated procedures and begin technical report

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Timeline (2012-2015)

Phase 4 - Submit report/procedures for comments and review from SC10

Phase 5 - Final report/procedures ratified by SC10

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Objectives for Phase 2 Testing Test a cement system that would show unique value of DST for

performance-based cement stability evaluationo 1. Pass GO/NO testing with minimal increase in BC (less than 50BC)o 2. Pass free fluid criteria with less than 1% free fluid.o 3. Pass sedimentation test criteria with less than 5% settlingo 4. Fail DST criteria with more than 5% change in density trend measured

down the length of the slurry HPHT cup after DST testing o 5.Fail DST cone height measurements (greater than 0.5 inch in height)

Add test procedures and interpretation guidelineso Define motor speed at 25 rpmo Ramp to BHCT following well schedule, Stabilize for at least 30 min, Turn

motor speed to 25 rpm for 30 min, Shutoff motor ensure lab to lab uniformity in low shear exposure period, cool to 190deg as soon as possible and perform measurements

o Use DST cone height results for under-dispersion/over-dispersion at HPHT conditions.

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Phase 2 – Updated DST Procedure and comparison with older versions of procedure Previous version(s) Updated version

Motor speed was varied between 25-35 rpm, depending on procedure

25 rpm is locked as the one motor speed

Motor speed was left at 25-35 rpm for at least 20 min period and cool-down period also

Motor speed is left at low shear for at least 30 minutes and then the motor is shut down before cool-down period

No attempt was made to quantify under and over-dispersion with DST

Attempt is made to quantify under and over-dispersion with DST with simple mathematical relationship

No density trend with syringes 10-mL tared syringes used to collect from upper, middle, and lower thirds of slurry cup

Only center cone height used as consideration Center, ½ radius or middle, and radius or outside positions are used in mathematical relationship = %deg dispersion = (center cone height-outside cone height)/center cone height x 100%

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Link to DST, GO/NO GO – Free Fluid, and Sedimentation Updated Procedures

Dynamic Settling Test Procedure _ Ramp up to 350 degF.docx

Free Fluid Test after Conditioning in HPHT Consistometer_15 May 2013.docx

API Sedimentation Test.docx

.\Unpacking List and Dynamic Weigh Out Sheet _CD_RHW_15 May 2013.pdfUnpacking List

DST Procedure

GO/NO and Free Fluid Procedure

Sedimentation Test

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Workgroup Cooperative Testing SummaryWorkgroup Members WG1 WG2 WG3 WG4 WG5 Ave STDev

BHCT (degF) 350GO/NO GO Init/Max BC NA 12/7 24/28 4/8 15/33 12/23 7/13Free Fluid (%) NA 0 0 5 1.3 1.6 2.4FF Angle (deg) NA 45 45 45 45 45 NASedimentation. Test (max dev.) (%) NA 3.0 1.7 NA 0.5 1.7 1.3Static Slurry Stability Achieved? Yes Yes Yes Yes -DST – dens top 1/3rd (lbm/gal) 15.4 15.9 15.2 14.5 13.7 14.9 0.9DST - dens mid 1/3rd (lbm/gal) 16.7 17.2 16.2 17.6 16.8 16.9 0.5DST – dens bott 1/3rd (lbm/gal) NA 16.9 16.7 18.2 16.9 17.2 0.7% difference density top-bottom 8.4 0 9.9 25.5 23.4 14.7 9.0Cone height – center (in.) 1 1.5 1.1 1.5 1.5 1.3 0.3Cone height – 1/2R or middle (in.) 0.63 1.5 1.1 0.8 1.3 1.1 0.4Cone height – R or outside(in.) 0.31 1.4 1.0 1.0 1.1 1.0 0.4Degree of dispersion (%)* 69 6.7 9.1 33.3 26.7 29.0 25.1DST Slurry Stability Criteria Achieved?** No No No No No No

* Greater than 50% difference between center and outside cone height indicates underdispersed slurry

** Less than 50% difference and cone height less than 0.5 in. for any measurement location is stable slurry as per DST criteria

1STD

2STD

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GO/NO GO Test Results

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GO/NO test observations after pulling paddle

SLB CSI

OTC

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Free fluid observations after conditioning in GO/NO GO test and 2 hrs at ambient temp as per API RP10B-2

SLB CSICVX

OFIte

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DST consistency behavior during motor speed at 25 rpm

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DST cone observations after revised DST procedure and removing modified paddle

CSISLB

OTC CVX

OFIte

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Go/No Go test results – Average Min/Max BC 12/23 with StDev 7/13 Free fluid test results at 45deg angle – Average 1.6% with StDev 2.4%

─ 2 workgroup members had 0% free fluid with 1 workgroup member showing 5.0% Static Sedimentation – Average 1.7% with STDev 1.3%

─ Depending on individual organization best practices, typically less than 5% is stable DST syringe density trend– Average 14.7% with STDev 9.0%

─ 2 workgroup members had less 10% and 2 had more than 23% DST cone height – Average 1.3,1.1,1.0 with STDev 0.3, 0.4, 0.4 Degree of Dispersion – Average 29.0% with STDev 25.1%

─ 1 workgroup member had outlier of 69% ─ Either procedure needs to be clarified further to emphasize unpacked cone over

packed cone for height measurements─ Perhaps angle of cone slope needs to be explored instead of % difference of height─ Other methods needs to be explored

Conclusions

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Our Roadmap…

• Collect more cooperative data from workgroup members• Look at alternative ways of describing dispersion

(slope of cone using Pythagorean theory?) • Write technical report/RP for workgroup input and

comments• Submit workgroup-validated report/RP to SC10 for

input and comments• Submit technical report/RP to SC10 for

vote/ratification

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Questions from the Audience