ABSTRACT
Incremental oil production response to steam-foam application can be accelerated by improved surfactant formulations and modification of techniques for foam emplacement. By considering the effect of gravity on surfactant and steam flow, a number of injection strategies for accelerating production response have been developed using a steam-foam simulator. The prototype model used, is an idealization of a section of Midway Sunset Field. Comparisons are made between various steam and foam injection strategies at different formation intervals. The results indicate that by injecting foam high in the structure while injecting steam near the bottom, production response can be accelerated over bottom injection alone. Maximum recovery can be achieved by gradually lowering the foam injection interval while injecting a portion of the foam near the bottom of the structure. Mechanically, these techniques can be implemented by multiple completion methods, simultaneous injection through tubing and annulus, or use of two adjacent wells for steam and steam-foam injection. Although demonstrated results are reservoir specific, the concept can be extended to other types of structures since the underlying principal deals with optimum placement of the surfactant for correcting gravity override.
