Polymer Gel Water-Shutoff Applications Combined With Stimulation Increase Oil Production and Life of Wells in the Monterey Formation Offshore California

Abstract

Abstract Excessive water production from the Monterey Formation of the Sockeye Field offshore Santa Barbara, California led the operator to consider polymer gel water shutoff treatments. Field water rates were approaching the limit of the platform water handling capacity and threatened to curtail future development and/or require a multi-million dollar facility expansion. By utilizing chromium crosslinked polyacrylamide gel technology, the operator significantly reduced the water production. However, after gel treatments were injected and the wells were returned to service, both water and oil production were significantly lower. The operator subsequently stimulated the wells with acid and saw significant increases in oil rates while maintaining a reduction in water production. The result of combining the water shutoff treatments with the stimulation was a lowered water production rate and increased oil rate that neither technique would have yielded on its own. At this time, four wells have been treated with both gel and acid and one has been treated with gel alone. Of the four treated with gel and acid, three had reduced water rates and three had increased oil rates. Moreover, all gel treatments were pumped down production tubing without the need of a rig, using the vendor's self-contained trailer that included all mixing and pumping equipment. While not specifically designed for offshore use, this equipment greatly simplified logistics and the total cost was low enough that the economics could be based solely on savings in water handling costs.