CO2 Foam Pilot in Salt Creek Field, Natrona County, WY - Phase I - Laboratory Work, Reservoir Simulation, and Initial Design

In this paper we describe the design of a CO2 foam pilot in the Salt Creek Light Oil Unit in Natrona County, WY. CO2 foam technology was chosen as a promising candidate to improve sweep efficiency in certain target patterns. The second Wall Creek (WC2) sandstone formation is the primary producing interval, with a net thickness of about 80 feet and at a depth of approximately 2,200 feet. The first screening step towards identifying a pilot area involved a detailed study of the geologic features, injection-production characteristics, and operational aspects of numerous patterns in the field. An injector centered five-spot pattern was selected for the pilot. A surfactant formulation was developed that provided the desired foam response at reservoir conditions, and also met preliminary economic and operational expectations. The foam characteristics of the surfactant were further investigated by performing core-flood experiments. A history matched reservoir simulation model was developed to forecast the performance of the field in the absence of foam and thus provide a baseline to compare with the anticipated foam response. The model was later calibrated with foam performance data and used to guide the implementation of the pilot and to forecast field performance. The pilot was initiated in September 2013. Initial results are discussed.