Preliminary Results From a Solvent Gas Injection Field Test in a Depleted Heavy Oil Reservoir

摘要

A field test was run during 1997 and 1998 to collect preliminary data on a solvent gas injection process. The site selected for the test was a "typical" Frog Lake, Alberta, Cummings formation reservoir that had been depleted using PC pump-based cold production methods on both 4 hectare (10 acre) and 8.1 hectare (20 acre) spacing. At the time of solvent injection, area average recovery from the test location was 9.5%, and the existence of wormholes in the reservoir was strongly suggested by regional well-to-well water migration and production of reservoir sand at high initial rates and cumulative volumes. A solvent containing 33 volume % propane and 67 volume % methane was injected at two converted central producers until cumulative volumes of 2 million m~3 and 4 million m~3 were achieved. This paper discusses field observations during the injection, soak, and production periods. A number of circumstances contributed to a poor economic result, but the operational and technical information obtained should prove helpful to operators considering application of, solvent injection processes.