Performance evaluation of CO2 flooding process in tight oil reservoir via experimental and numerical simulation studies. (15th January 2019)

• Record Type: Journal Article
• Authors: Zhou, Xiang; Yuan, Qingwang; Zhang, Yizhong; Wang, Hanyi; Zeng, Fanhua; Zhang, Liehui
• Is Part Of: Fuel. Volume 236(2019)
• Page Start: 730
• Page End: 746
• Publication Date: 2019-01-15
• Subjects: Performance evaluation -- CO2 flooding process -- Tight oil reservoir -- Production performance; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2018.09.035
• Languages: English
• ISSNs: 0016-2361

Abstract

Highlights: CO2 flooding process is conducted in a one-meter long core plugs. High agreement history matches are obtained to direct the further studies. Sensitivity analysis show the effect of parameters and help in the optimization process. The optimized parameters in the upscaling study can be applied in field application. Abstract: In this study, experimental and numerical simulation studies were conducted to enhance oil production in a tight oil reservoir using CO2 injection processes. In experimental studies, three types of CO2 injection experiments—CO2 flooding (continuous CO2 injection process), CO2 flooding coupled with a soaking period, and CO2 flooding coupled with pressure maintenance—were carried out in one-meter-long core plugs to investigate the effect of CO2 flooding schemes on production performance. The properties of light oil–CO2 systems with different CO2 concentrations under different pressures were measured to study the phase behaviors of light oil–CO2 systems. Test results indicate that the CO2 flooding process is the best method to enhance oil recovery in tight formations, showing an oil recovery factor of 38.96% and a CO2 utilization of 10.41 Mscf/STB. In numerical simulation study, the properties of light oil–CO2 systems first were simulated using the WinProp module. Next, the GEM module was applied to implement history-matching studies on experimental results, and good agreement was achieved. Third, a sensitivity analysis was carried out to investigate the effect of parameters on the CO2 flooding process. Finally, upscaling simulation studies were conducted at the field scale to optimize the well pattern and CO2 injection rate to enhance oil recovery in the target reservoir. Important correlations on the effect parameters were generated for predicting the oil production performance in the reservoir with different operations. Among the studied well patterns, the inverted seven-spot well pattern with a CO2 injection rate of 44.28 t/day/well achieved the best production performance in the field study. In the optimized case, the oil recovery factor reached 30.89% with a low CO2 utilization of 5.69 Mscf/STB.