El Dorado Micellar-Polymer Project Facility
Authors: Miller R.J. , Richmond C.N. 
Published: December 2007

This paper investigates the feasibility of recovering additional oil with the micellar-polymer flooding method. A demonstration project in the El Dorado field of Butler County, Kans., allows a comparison of two different processes in the same field. The benefits and problems associated with each micellar-polymer flooding process are being determined.

Introduction
Liquid hydrocarbons currently supply about 50 percent of the energy consumed in the United States. However, recoverable domestic oil reserves are declining faster than they are being replaced. It is estimated that 59 billion bbl of additional oil can be recovered by enhanced oil recovery methods that include micellar-polymer flooding techniques.1 Cities Service Co. (CSC) in cooperation with the U.S. Energy Research and Development Administration (ERDA) selected the El Dorado field in Butler County, Kans., for the demonstration of two distinctly different micellar-polymer processes (see Fig. 1 for location map).
The primary objectives of this project are to investigate the economic. feasibility of enhanced (in this case, tertiary) oil recovery using micellar-polymer processes and to determine the benefits and problems that are associated with each method tested.
The proposed project is being conducted in the 650-ft shallow sand of the Admire group in the base of the Permian section. Sand thicknesses varied up to 30 ft in association with numerous mini-structures. The 650-ft sand has been described as a deltaic environment with intermixing swamp, bay, and distributary channel deposits. The average porosity is 24 percent with permeabilities ranging up to 1,500 md. Other reservoir parameters for the project are shown in Table 1.
The total areal extent of the 650-ft sand reservoir is more than 6,200 acres. The original oil in place is estimated at approximately 108 million bbl. Primary and air-drive operations recovered 23 million bbl of oil. Production records made it difficult to allocate the recovery to individual mechanisms. The waterflood phase recovered 13.5 million bbl of oil, which leaves an estimated 71.5 million bbl of oil remaining in place. Water injection was terminated in Feb. 1971 and essentially all wells in the 650- ft sand had been plugged before beginning this project. Accordingly, oil recovered from the demonstration project will be considered tertiary oil.

Discussion

Project Description
The proposed project was designed to allow a side-by-side comparison of two micellar-polymer processes in the same field so that reservoir conditions were as similar as possible. The original pattern configuration was four contiguous nine-spots in each 25.6-acre pattern.2 Subsequent detailed modeling and pressure transient study indicated that the optimum pattern should be an array of four 6.4-acre five-spots.3,4 As shown in Fig. 2, the Chesney-Hegberg lease line divided the project area at the northern side of the south (Hegberg) pattern. Each pattern consisted of nine injection, four production, 12 monitoring, and two observation wells. The injection plant, shown near Well MP-104, was designed to serve both patterns.

Project Description
The proposed project was designed to allow a side-by-side comparison of two micellar-polymer processes in the same field so that reservoir conditions were as similar as possible. The original pattern configuration was four contiguous nine-spots in each 25.6-acre pattern.2 Subsequent detailed modeling and pressure transient study indicated that the optimum pattern should be an array of four 6.4-acre five-spots.3,4 As shown in Fig. 2, the Chesney-Hegberg lease line divided the project area at the northern side of the south (Hegberg) pattern. Each pattern consisted of nine injection, four production, 12 monitoring, and two observation wells. The injection plant, shown near Well MP-104, was designed to serve both patterns.