Caustic Waterflooding Demonstration Project: Ranger Zone, Long Beach Unit, Wilmington Field, California. Third Annual Report, June 1978-May 1979

摘要

A caustic-enhanced waterflooding pilot test is being conducted in the Ranger Reservoir of the Long Beach Unit, Wilmington Field, California. Evaluation of entrapment and entrainment caustic flooding in Ranger Zone cores was continued. The caustic-only (entrapment) core floods failed to demonstrate improved behavior. Based on the unfavorable results of all tests of the entrapment mechanism, further laboratory work and flooding in the pilot with caustic alone have been eliminated from the project's plans. Some of the year's caustic-salt (entrainment) core floods in contrast showed both substantial recovery and WOR improvement. The poorer overall entrainment core flood results obtained in the year may be due to the core material, a smaller preflush volume used or the crude oil employed. Core flood testing where sodium silicate is substituted for some of the sodium hydroxide, was continued. The primary set of caustic water-oil dehydration tests was completed. The test softening of produced waters was completed and the results evaluated; produced water softening was found to be an economically feasible alternative to the use of fresh water. The preflush injection facilities became operational in January 1979 with the pilot's preflush officially begun April 15, 1979. The alkaline injection facility was expanded in scope to permit use of both sodium silicate and sodium hydroxide; its completion in late 1979 is anticipated with the alkaline-salt injection scheduled to begin at that time. The base case reservoir simulator prediction of the pilot under continued waterflooding was completed. This prediction provided the base line from which incremental alkaline flood production will be determined, as the test has now been declared a qualified tertiary enhanced recovery project by DOE's Economic Regulatory Administration. Major well repair/redrill work continued to be necessary exceeding earlier increased cost estimates. (ERA citation 05:011208)