RPSEA Phase 2
RPSEA Funded Research
Characterization of Potential Sites for Near Miscible CO2 Applications to Improve Oil Recovery in Arbuckle Reservoirs
Arbuckle reservoirs have significant potential in Kansas for Improved Oil Recovery (IOR). The Arbuckle has produced an estimated 2.2 billion barrels of oil representing 35% of the 6.1 billion barrels of oil of total Kansas oil production. Because of the characteristic production history, Arbuckle reservoirs have been viewed as fracture-controlled karstic reservoirs with strong pressure support from either a bottom water or edge water aquifer. A common practice of operation in Arbuckle reservoirs is to drill the well into the top of the zone with relative shallow penetration and complete open hole. No waterflooding application has been reported in these reservoirs in the published resources.
Our research results on carbon dioxide (CO2) IOR in Arbuckle reservoir at Ogallah field shows a favorable mechanism to improve oil recovery with CO2 near miscible conditions which are 110 °F and 1150 psi. However, due to the lack of coring, modern well logging, and well testing in the past, Arbuckle reservoirs have not been well characterized. Current understanding of the Arbuckle is based on a conceptual model with limited petrophysical, drill stem test and pressure build up data. The uncertainty of reservoir properties places a challenge for an IOR application in Arbuckle reservoirs as the nature of flow is affected by reservoir properties and heterogeneity.
In order to ultimately predict improved oil recovery in a future CO2 flood, we propose an evaluation plan to seek data that pertain to the pressure, residual oil saturation, reservoir properties and the nature of the flow from well to well. We propose that single well transient pressure tests, multiple well interference tests, single well tracer tests, and interwell tracer tests be conducted. All tests will be designed to determine the nature of the flow paths and average properties in the reservoir, to assess the effect of geology on process performance, to calibrate a reservoir simulation model, and to identify operational issues and concerns for future IOR applications.
The proposed work will be conducted by the Tertiary Oil Recovery Project (TORP) at the University of Kansas at selected oil fields in Arbuckle reservoirs. With improved reservoir characterization as a result of this proposed approach, a first near miscible CO2 application based upon a better description of the reservoir system could be field tested to prove the technology leading to additional oil recovery from Arbuckle reservoirs in Kansas. The potential benefits will be significant with an increase in the resource base for CO2 flooding and an expanded opportunity for small producers to apply CO2 flooding.
The participating consortiums include University of Kansas Center for Research, Inc., Tertiary Oil Recovery Project, University of Kansas, Kansas Geological Survey and small producer, Carmen Schmitt, Inc.