The completion fluid design for the carbonate reservoir was to sustain a bottomhole temperature (BHT) of 340 degF [171 degC] with a minimum barite sag profile. It was critical for the fluid design to be sag resistant and technically able to sustain the BHT for at least 7 days of static period without reconditioning of the fluid.
The previously used completion fluid did not allow for proper inflation of completion packers and the operator suspected that this was due to sag of the trimanganese tetra oxide fluid.
SLB proposed use of an invert-emulsion fluid weighted up with a combination of WARP OB CONCENTRATE concentrated colloidal suspension technology and WARP UF 44 high-density micronized weight material. The WARP technology ensured low-rheology drilling fluid without barite sag and with exceptionally stable fluid properties through micron-sized weighting materials 10 times smaller than drilling-grade barite.
The completion and testing string were run without any restrictions. All testing tools and valves operated without any troubleshooting. After the 120-h static period without conditioning the fluid and circulation, the invert-emulsion WARP advanced fluids technology showed no sag and no fluctuations in nominal mud weight recorded, indicating the fluid remained stable. Testing of two production zones did not show any signs of reservoir damage.
