DESIGN AND FIELD TRIAL APPLICATION OF FOAM IN PRODUCTION WELLS TO IMPROVE CONFORMANCE

Many of the hydrocarbon vertical miscible floods in the Keg River carb onate reefs of the Rainbow Field are at a mature stage of reservoir de pletion, and are characterized by thin oil sandwiches, high gas recycl e and declining oil production. Under these adverse conditions, conven tional workover techniques to control gas recycle and improve oil prod uctivity have diminishing success. In considering alternative strategi es to reduce gas coning Husky felt that injection of a gas-blocking fo am barrier into a gas cone had the potential to be a cost-effective tr eatment. This paper describes the experimental foam treatments conduct ed on two production wells, each in a different miscible flood pool. A spects of the laboratory work, numerical coning simulation, well selec tion process and foam placement strategy that went into the field trea tment design are presented. On one ,well,the foam-forming surfactant w as injected as an aqueous solution to allow in situ foam generation, a nd also as a surface-generated preformed foam. Neither method was succ essful in improving the performance of this well. On the other well, w here only preformed foam was injected, the treatment was successful in reducing gas-oil ratio (GOR) and improving oil production over a 14 m onth period. Much of the experience gained from the field treatments w ill facilitate the efficient planning, design, implementation and eval uation of future foam projects.