Carbon sequestration with enhanced gas recovery: Identifying candidate sites for pilot study

Depleted natural gas reservoirs are promising targets for carbon dioxide sequestration. Although depleted, these reservoirs are not devoid of methane, and carbon dioxide injection may allow enhanced production of methane by reservoir repressurization or pressure maintenance. Based on the favorable results of numerous simulation studies, we propose a field test of the Carbon Sequestration with Enhanced Gas Recovery (CSEGR) process. The objective of the field test is to evaluate the feasibility of CSEGR in terms of reservoir processes such as injectivity, repressurization, flow and transport of carbon dioxide, and enhanced production of methane. The main criteria for the field site include small reservoir volume and high permeability so that increases in pressure and enhanced recovery will occur over a reasonably short time period. The Rio Vista Gas Field in the delta of California's Central Valley offers potential as a test site, although we are currently looking broadly for other potential sites of opportunity