An Economic Polymerflood in the North Burbank Unit, Osage County, Oklahoma
Authors: Clampitt R.L. , Reid T.B. 
Published: December 2007

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc.

Four years of performance of a 160-acre polymer flood in the Burbank Sand of the North polymer flood in the Burbank Sand of the North Burbank Unit, Osage County, Okla., has indicated that polymer flooding is an economic tertiary process after waterflooding for those parts of the unit having high permeability parts of the unit having high permeability variation. The initial cost of the Chemicals and equipment was paid out after 26 months of operation, and after 4 years of operation the project has produced 76,500 bbl of incremental project has produced 76,500 bbl of incremental oil. The incremental rate of oil production was 50 to 60 B/D as of Dec. 31, 1974.

The project consisted of four injection wells in two rows offset by 12 producing wells aligned in three rows of four wells each. Injection of the polyacrylamide solution in the four input wells began in Oct. 1970 and was stopped in June 1971 after the injection of 84,500 lb of polyacrylamide (Dow Pusher 1000) dissolved in 1.7 mill-ion bbl of fresh water.

Introduction

Oil recovery by waterflooding in certain areas of the North Burbank Unit, Osage County, Okla. (Fig. 1) has been about half that in other portions of the unit. As a result, a three-part portions of the unit. As a result, a three-part study was undertaken to determine if water diversion agents, such as the polyacrylamides, would improve the oil recovery in these areas. In the first part, a reservoir study showed that poor sweep efficiency of the reservoir by the poor sweep efficiency of the reservoir by the injected water resulted in the low recovery. The poor sweep efficiency in Tract 49 was caused primarily by the large variation in permeability primarily by the large variation in permeability (0.87 Dykstra Parsons kv) in the vertical direction. Calculations made using a layered reservoir model indicated 90 percent of the injected water was channeling through high permeability zones consisting of only 15 percent permeability zones consisting of only 15 percent of the reservoir. Additional calculations indicated that polyacrylamides could reduce the channeling through these high permeability zones and thereby accelerate the rate of flooding of the lesser permeable zones.

In the second part, flow characteristics of polymer solutions in Burbank sandstone cores polymer solutions in Burbank sandstone cores were measured in the laboratory and used in a polymer-flood computer model to estimate polymer-flood computer model to estimate incremental oil that could be expected from a field test of polyacrylamides. The validity of the reservoir properties and the stimulation model were established by obtaining a 10-year history match of the waterflood. Because of the successful history match, the promising laboratory tests, the additional quantity of oil predicted by the computer model, and the predicted by the computer model, and the indicated favorable economics, a field test of polymer flooding was designed and installed in polymer flooding was designed and installed in 1970 on a 160-acre area in Tracts 40 and 49 (Fig 2).