Alternative Mixing Procedure RP 10 B2 Saudi Aramco

Alternative Mixing Procedure RP 10 B-2 Saudi Aramco: Company General Use

Preparation of Slurries Saudi Aramco: Company General Use

The Problem • Cement slurries foam • Non-foamer not effective in some cases • Latex / thixotropic / high density slurries • Results in testing - a lesser amount (mass) of cement slurry • Excess foaming affects • • • Thickening time tests Sedimentation Free water Rheology Compressive strength Expansion Saudi Aramco: Company General Use

Alternative Mixing Procedure cont’d Thickening Time Test • Lesser amount of slurry is placed in the slurry cup • 2 thoughts to correct / compensate 1. Change diaphragm • Hub baffled • Flat rubber • Flat metal / flat rubber on top 2. Pull Vacuum on slurry • 0. 1 atm in SA Lab 15700 -1 -1 15700 -1 -2 15700 -1 -3 15700 -1 -4 Thickening time start Bc 4, 3: 00 Bc 4 Thickening time start Bc 11, 3: 00 Bc 9 Thickening time start Bc 7, 3: 00 Bc 2 Thickening time start Bc 10, 3: 00 Bc 6 normal, rubber flat diaphragm 1. 5 mins vacuum, rubber flat diaphragm normal, metal flat diaphragm 1. 5 mins vacuum, metal flat diaphragm Saudi Aramco: Company General Use

Diaphragm Choices • Hub baffled • Flat rubber • Flat metal flat rubber on top Saudi Aramco: Company General Use

Baffled Diaphragm Saudi Aramco: Company General Use

Applying Vacuum Saudi Aramco: Company General Use

Effects of Foaming Volume after mixing Volume after vacuum released Volume Theoretical 15700 -1 -2 cc's difference from original Volume slurry 615 0 vol after mixing 811 196 vol after Vacuum 661 46 Saudi Aramco: Company General Use vol after release vac 737 122 % 0. 0 31. 9 7. 5 19. 8 cc's 615 676 623 651 15700 -1 -6 diff 0 61 8 36 % 0. 0 9. 0 1. 3 5. 5

Observations on Cements that Foam (consistometer test cell) vol with diaphragm flat 477 cc's baffled 472 cc's Cement design 1 2 Density PCF/PPG atm bal. 113/15. 1 111/14. 8 press bal. 118. 5/15. 8 125/16. 7 % 4. 87 12. 61 m. L missing 21. 90 56. 76 Saudi Aramco: Company General Use

Lab Equipment Exist – Modified Foam Jar Connect fitting to jar cover to accommodate vacuum fittings Saudi Aramco: Company General Use

Way Forward? Saudi Aramco: Company General Use

Thickening Time Stirring RPMs Why • Do we stir at 150 RPMs? • • • Old procedure for salt cement - Calvert? Do we simulate batch mixing at same RPM’s as pumping cement through Coiled tubing? ? Concerned with 50 sec initial mixing RPMs but 150 rpms is ok for long thickening times? • 10 hours = 36, 000 sec Velocity changes from different well geometries ie. slurry inside casing then in annulus Thickening time test performed at 200, 150, 100 and 50 rpms. • longer thickening times are recorded as RPMs are reduced. • 50 RPMs – 173 mins. • 100 RPMs – 169 mins. • 150 RPMs – 148 mins. • 200 RPMs - 151 mins Saudi Aramco: Company General Use