The Weeks Island S sand Reservoir B (S RB) gravity-stable CO2 field test is almost complete. Injection started in October 1978 and production began in January 1981 in this high-permeability, steeply dipping sandstone reservoir. Through 1987, about 261,000 barrels of oil or about 64 percent of the starting volume has been recovered. A 24-percent pore-volume slug of CO2 mixed with about six mole percent of natural gas (mostly methane) was injected at the start of the pilot. During 1983, when gas production rates started to increase, CO2 containing produced gas was reinjected. Through 1987, CO2 usage statistics are 7.90 MCF/B0 with recycle and 3.26 MCF/B0 based on purchased CO2.

This report is a review of early pilot history and a more detailed account of the post-June 1981 results. A reservoir-simulation history match of pilot performance plus core and log data from a 1983 swept-zone evaluation well are included.

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