Challenge: Perform zonal isolation prior to gravel packing using OptiPac Alternate Path openhole gravel-pack screen with a 100% oil-base fluid to enable packer swelling while maintaining hydrostatic pressure.
Solution: Prepare and deploy PRIMO-SWELL oil-swellable packer activation system, which contains no emulsifiers or wetting agents and maintains compatibility with water-base filtercakes.
Results: Maintained well control requirements to enable completion installation and successful gravel packing on critical well.
An operator in Colombia was planning to drill a reservoir with a water-base drilling fluid because of the region’s environmental sensitivity. The planned completion included fast oil-swell packers. Originally, diesel was used to swell the packers, but increased density requirements mandated a weighted fluid. Conventional invert emulsions are not compatible with the water-base filtercake left by the drilling process and risked formation damage and equipment plugging. Therefore, an all-oil system was required.
SLB suggested the PRIMO-SWELL system, an all-oil packer activation system that maintains compatibility with water-base filtercakes. The PRIMO-SWELL system comprises the PRIMO-VIS oil-swell packer activation fluid viscosifier for suspension and WARP DRY CC calcium carbonate high-density colloidal suspension technology to provide higher density to mineral-oil- and diesel-base fluids. Both products feature a very small particle size distribution to mitigate the risk of screen plugging.
SLB engineers tested the solution based on downhole parameters to ensure that the solution would meet the operator’s objectives. The engineers prepared an 8.6-lbm/galUS PRIMO-SWELL system and static aged the fluid at the bottomhole temperature of 180 degF [82.2 degC] for 20 h—the time required to swell the packers. The laboratory sample demonstrated consistent rheology with no significant phase separation. When tested on a production screen tester, the sample gave no indication of plugging through 250-um premium mesh screens.
The diesel-base PRIMO-SWELL system was prepared on location and properties checked. With the lower completion on bottom, 80 bbl [12.72 m3] of PRIMO-SWELL system was spotted in place at 4 bbl/min [0.64 m3/min] using 20-bbl [3.18-m3] lead and 20-bbl tail viscous spacers to minimize interface. The well was then shut in for 24 h to allow the swell packers to expand as they soaked in the PRIMO-SWELL system. Thereafter, the OptiPac Alternate Path openhole gravel-pack screen job commenced and was executed successfully.
