Improved Oil Recovery with Near-miscible Carbon Dioxide Application in Arbuckle Reservoir at Ogallah Field
Reza Maleki and Jyun Syung Tsau
Arbuckle reservoirs have significant potential in Kansas for Improved Oil Recovery (IOR). These reservoirs have produced an estimated 2.2 billion barrels of oil representing 35% of the 6.1 billion barrels of oil of total Kansas oil production. After years of production, 90% of wells are operated at rate less than 5 barrels of oil per day with a considerable volume of oil remained as target for improved oil recovery (IOR). Assessment of CO2 miscible flooding in these Arbuckle reservoirs, however, indicates that miscibility is not achievable at the reservoir operating pressure. Recent laboratory research suggested a favorable mechanism to improve oil recovery with CO2 injection at near miscible conditions where the operating pressure is slightly below minimum miscibility pressure (MMP). Extraction of light hydrocarbon constituents into the CO2 rich vapor phase and reduction of oil viscosity are the primary mechanisms for the near miscible displacement process. In this paper, an improved reservoir model describing Arbuckle reservoir at Ogallah oil field will be presented. Computation study on characterization of fluid phase behavior, the displacement process and oil recovery under near miscible conditions as well as CO2 injection pattern design will be discussed. Substantial increase of oil production resulting from CO2 injection at near miscible condition will be demonstrated.
AAPG Search and Discovery Article #90176©AAPG Mid-Continent Meeting, Wichita, Kansas, October 12-15, 2013