1Dynamic 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, OFIteJune 25th, Houston, TX
2Agenda 1. Minutes of Previous Meeting and Action Items 2. Overview of Workgroup objectives/progress3. Procedures to run dynamic vs. static testing for Workgroup4. Summary of API Cooperative test results5. Our roadmap moving forward
3Minutes of Previous Meeting 4/15/2017Minutes of Previous MeetingTG on Test Methods for Determination of Dynamic SettlingSeveral task group members were present.Meeting Minutes for January 22nd, 1:15pm held at the Intercontinental New Orleans, LAReview 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 DSTA system that will pass the free fluid but fail the DST is still being designedThe 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 ItemsAfter much discussion it was decided to pursue the development of Designs 1 and 2Continue the round robin testing for the next meeting in the summer.Designing system for round robin testing that passes static criteria and fails dynamic criteriaUpdating 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.Cement DesignCement treatmentNatural causesPost-placement stressesIndicates Action Items that have been completed
4Completion/Progress and Projected Timeline Explored DST alternatives100%Phase 1 – showed systems that passed/failed Static and DST80%Phase 2 – cement failed DST but passed static% Workgroup CompletionPhase 2 – Updated procedures and begin technical report60%Phase 3 - Submit report/procedures for comments and review from DST Workgroup40%Phase 4 - Submit report/procedures for comments and review from SC1020%Phase 5 - Final report/procedures ratified by SC100%
5Objectives for Phase 2 Testing Test a cement system that would show unique value of DST for performance-based cement stability evaluation1. Pass GO/NO testing with minimal increase in BC (less than 50BC)2. Pass free fluid criteria with less than 1% free fluid.3. Pass sedimentation test criteria with less than 5% settling4. Fail DST criteria with more than 5% change in density trend measured down the length of the slurry HPHT cup after DST testing5.Fail DST cone height measurements (greater than 0.5 inch in height)Add test procedures and interpretation guidelinesDefine motor speed at 25 rpmRamp 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 measurementsUse DST cone height results for under-dispersion/over-dispersion at HPHT conditions.
6Phase 2 – Updated DST Procedure and comparison with older versions of procedure Previous version(s)Updated versionMotor speed was varied between rpm, depending on procedure25 rpm is locked as the one motor speedMotor speed was left at rpm for at least 20 min period and cool-down period alsoMotor speed is left at low shear for at least 30 minutes and then the motor is shut down before cool-down periodNo attempt was made to quantify under and over-dispersion with DSTAttempt is made to quantify under and over-dispersion with DST with simple mathematical relationshipNo density trend with syringes10-mL tared syringes used to collect from upper, middle, and lower thirds of slurry cupOnly 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%
7Link to DST, GO/NO GO – Free Fluid, and Sedimentation Updated Procedures Unpacking List.\Unpacking List and Dynamic Weigh Out Sheet _CD_RHW_15 May 2013.pdfDST ProcedureDynamic Settling Test Procedure _ Ramp up to 350 degF.docxGO/NO and Free Fluid ProcedureFree Fluid Test after Conditioning in HPHT Consistometer_15 May 2013.docxSedimentation TestAPI Sedimentation Test.docx
8Workgroup Cooperative Testing Summary Workgroup MembersWG1WG2WG3WG4WG5AveSTDevBHCT (degF)350GO/NO GO Init/Max BCNA12/724/284/815/3312/237/13Free Fluid (%)126.96.36.199FF Angle (deg)45Sedimentation. Test (max dev.) (%)3.01.70.5Static Slurry Stability Achieved?Yes-DST – dens top 1/3rd (lbm/gal)15.415.915.214.513.714.90.9DST - dens mid 1/3rd (lbm/gal)16.7188.8.131.526.816.9DST – dens bott 1/3rd (lbm/gal)18.20.7% difference density top-bottom8.49.925.523.414.79.0Cone height – center (in.)184.108.40.206Cone height – 1/2R or middle (in.)0.630.80.4Cone height – R or outside(in.)0.311.41.0Degree of dispersion (%)*6220.127.116.116.729.025.1DST Slurry Stability Criteria Achieved?**No1STD2STD* 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
10GO/NO test observations after pulling paddle SLBCSIOTC
11Free fluid observations after conditioning in GO/NO GO test and 2 hrs at ambient temp as per API RP10B-2SLBCVXCSIOFIte
12DST consistency behavior during motor speed at 25 rpm
13DST cone observations after revised DST procedure and removing modified paddle SLBCSIOFIteOTCCVX
14ConclusionsGo/No Go test results – Average Min/Max BC 12/23 with StDev 7/13Free 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 stableDST 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, 0.4Degree 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 measurementsPerhaps angle of cone slope needs to be explored instead of % difference of heightOther methods needs to be explored
15Collect more cooperative data from workgroup members Our Roadmap…Collect more cooperative data from workgroup membersLook at alternative ways of describing dispersion (slope of cone using Pythagorean theory?)Write technical report/RP for workgroup input and commentsSubmit workgroup-validated report/RP to SC10 for input and commentsSubmit technical report/RP to SC10 for vote/ratificationIn this roadmap slide, I will discuss potential exploration of Futur US as an additional cost-effective cement solution in our portfolio with the emphasis on D204’s self healing properties…but will not put Futur US on the roadmap slide.