Coupled CO2 Enhanced Oil Recovery and Sequestration in China's Demonstration Project: Case Study and Parameter Optimization

Reservoir stimulation by carbon dioxide (CO2) flooding can bring extra oil production because of its unique advantages of higher displacing efficiency and lower injection pressure compared to water flooding. Also, greenhouse gas control has been the focus of worldwide attention in recent decades, and CO2 injection into reservoirs has been regarded as a favorable method of achieving sequestration. Therefore, coupled enhanced oil recovery (EOR) and sequestration becomes a cost-effective and environmentally safe method, which is feasible for developing countries, especially China. In this paper, China's first field-scale reservoir demonstration project is introduced to evaluate its performance with respect to both oil recovery and carbon sequestration. Also, given that injected CO2 tends to immaturely break through toward production wells in reservoirs, parameters of recycled gas injection scenarios were screened and then optimized by experimentations as well as by a new optimizing method. Both of these approaches could contribute to the research and methodology required for scaling up programs in China.