Improved Secondary Oil Recovery by Controlled Waterflooding-Pilot Demonstration: Ranger Zone, Fault Block VII, Wilmington Field. Phase IV. Quarterly Report, January-March, 1983

摘要

The project is an improved waterflood demonstration of alkaline waterflooding in a typical well flood pattern of the Ranger Zone of the Long Beach Unit portion of the Wilmington Field. A mixture of 0.4% sodium hydroxide and sodium silicate in fresh water containing 0.75 to 1.0% salt is being injected to improve oil recovery. The demonstration pattern in which DOE participated involves the input of approximately 30,000 to 34,000 B/D water in 8 injection wells which surround 11 active producers in an area of 93 acres. Reservoir engineering studies have shown that the total area being affected by the injection in these 8 wells is much larger, being approximately 200 acres including areas situated both north and south. If the alkaline injection is successful, improved flood efficiency should occur as demonstrated by reduced water-oil ratios and increased oil recovery. Chemical injection continued in the quarter. A simple long term solution to the floc formed on mixing the dilute alkaline solution with the concentrated salt brine was not found. Alternating one week slug injection of soft water with alkali and then soft water with salt continued throughout the quarter. A four-hour soft water spacer with no chemicals was placed between the slugs. Injection data and graphs showing performance of the area are presented. 7 figures, 2 tables. (ERA citation 08:050633)