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Dynamic Settling/Stability Workgroup – Summer 2013 Robert Beirute, Beirute Consulting; Heath Williams, Schlumberger; Paul Sonnier and Jeff Watters, CSI,

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Presentation on theme: "Dynamic Settling/Stability Workgroup – Summer 2013 Robert Beirute, Beirute Consulting; Heath Williams, Schlumberger; Paul Sonnier and Jeff Watters, CSI,"— Presentation transcript:

1 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 25 th, Houston, TX

2 2 Schlumberger Confidential 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

3 3 Schlumberger Confidential Minutes of Previous Meeting TG on Test Methods for Determination of Dynamic Settling Several task group members were present. Meeting Minutes for January 22 nd, 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

4 4 Schlumberger Confidential 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 Phase 2 – Updated procedures and begin technical report 100% 80% 60% 40% 20% 0% % Workgroup Completion Timeline ( ) Phase 4 - Submit report/procedures for comments and review from SC10 Phase 5 - Final report/procedures ratified by SC10

5 5 Schlumberger Confidential Objectives for Phase 2 Testing  Test a cement system that would show unique value of DST for performance-based cement stability evaluation o 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% settling o 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 guidelines o Define motor speed at 25 rpm o 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.

6 6 Schlumberger Confidential Phase 2 – Updated DST Procedure and comparison with older versions of procedure Previous version(s)Updated version Motor speed was varied between rpm, depending on procedure 25 rpm is locked as the one motor speed Motor speed was left at 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 syringes10-mL tared syringes used to collect from upper, middle, and lower thirds of slurry cup Only center cone height used as considerationCenter, 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%

7 7 Schlumberger Confidential 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.pdf Unpacking List DST Procedure GO/NO and Free Fluid Procedure Sedimentation Test

8 8 Schlumberger Confidential Workgroup Cooperative Testing Summary Workgroup MembersWG1WG2WG3WG4WG5AveSTDev BHCT (degF) 350 GO/NO GO Init/Max BC NA 12/724/28 4/8 15/3312/23 7/13 Free Fluid (%) NA FF Angle (deg) NA45 NA Sedimentation. Test (max dev.) (%) NA3.01.7NA Static Slurry Stability Achieved? Yes - DST – dens top 1/3 rd (lbm/gal) DST - dens mid 1/3 rd (lbm/gal) DST – dens bott 1/3 rd (lbm/gal) NA % difference density top-bottom Cone height – center (in.) Cone height – 1/2R or middle (in.) Cone height – R or outside(in.) Degree of dispersion (%)* DST Slurry Stability Criteria Achieved?** 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

9 9 Schlumberger Confidential GO/NO GO Test Results

10 10 Schlumberger Confidential GO/NO test observations after pulling paddle SLBCSI OTC

11 11 Schlumberger Confidential Free fluid observations after conditioning in GO/NO GO test and 2 hrs at ambient temp as per API RP10B-2 SLB CSI CVX OFIte

12 12 Schlumberger Confidential DST consistency behavior during motor speed at 25 rpm

13 13 Schlumberger Confidential DST cone observations after revised DST procedure and removing modified paddle CSISLB OTCCVX OFIte

14 14 Schlumberger Confidential  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

15 15 Schlumberger Confidential 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

16 16 Schlumberger Confidential Questions from the Audience


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