ABSTRACT
The North Burbank Unit commercial scale polymerflood project began in September, 1980, with the injection of fresh water preflush within a 1440 acre polymerflood project area. Since that time polymer solution at 500 ppm concentration, interrupted by aluminum citrate, and polymer solutions of 2 50 and 50 ppm concentration have been injected. The total polymer to be injected is 4,001,000 pounds of a liquid emulsion polyacrylamide.
This paper deals with operational problems encountered during the project and the response of the project wells to polymer injection. The discussion of operational problems includes shear degradation of the polymer solution, disposal of produced brine, biocide effectiveness, and near wellbore treatments to adjust injection rates into individual injection wells. The response of the project producing wells includes fresh water breakthrough, polymer production, and oil production response to polymerflooding. The discussion of the response of the project injection wells includes injection rate and wellhead pressure histories, and analysis of pressure falloff tests before and during polymer injection.
The project area has responded positively to polymer injection with the production rate from the project area currently averaging 951 barrels of oil per day compared with a pre-project rate of 510 BOPD. The producing water-oil ratio has correspondingly declined frcm a pre-project water-oil ratio of over 100 to a current ratio of less than 50. The interior pattern wells have shown the best response to polymerflooding with the wells on the outside of the project area showing very little response to polymer injection.
