CO2 Huff-n-Puff: Initial Results from a Waterflood SSC Reservoir

Abstract

Abstract The application of cyclic CO2, often referred to as the CO2 Huff-n-Puff (H-n-P) process, may find its niche in the maturing waterfloods of the Permian Basin. Coupling the CO2 H-n-P process to miscible flooding applications could provide the needed revenue to sufficiently mitigate near-term negative cash flow concerns in these capital intensive projects. Initial results from a field demonstration of the process are provided. The paper briefly reviews the reservoir characterization associated with the project and the compositional simulation of the CO2 H-n-P process. Simulation results suggest that reservoir characterization of flow units is not as critical for a CO2 H-n-P process as for a miscible flood. Entrapment of CO2 by gas hysteresis is considered the dominant recover» factor for a given volume of CO2. The repetitive application of the process was found to be unwarranted in a waterflooded environment. Future history matching of the performance will allow better forecasts and evaluation of the economic impact available with this underutilized process.