Less than 10% of oil is usually recovered from liquid-rich shales and this leaves much room for improvement, while water injection into shale formation is virtually impossible because of the extremely low permeability...Less than 10% of oil is usually recovered from liquid-rich shales and this leaves much room for improvement, while water injection into shale formation is virtually impossible because of the extremely low permeability of the formation matrix. Injecting carbon dioxide（CO2） into oil shale formations can potentially improve oil recovery. Furthermore, the large surface area in organicrich shale could permanently store CO2 without jeopardizing the formation integrity. This work is a mechanism study of evaluating the effectiveness of CO2-enhanced oil shale recovery and shale formation CO2 sequestration capacity using numerical simulation. Petrophysical and fluid properties similar to the Bakken Formation are used to set up the base model for simulation. Result shows that the CO_2 injection could increase the oil recovery factor from7.4% to 53%. In addition, petrophysical characteristics such as in situ stress changes and presence of a natural fracture network in the shale formation are proven to have impacts on subsurface CO2 flow. A response surface modeling approach was applied to investigate the interaction between parameters and generate a proxy model for optimizing oil recovery and CO2 injectivity.展开更多
自上世纪70年代以来,CO2驱提高采收率技术在油藏工程理念上已形成连续CO2注入、恒定比例C-WAG(Constant Water-Alternating-Gas)注入、梯度/混合-WAG注入(Tapered/Hybrid WAG Injection)以及SWG(Simultaneous Water and Gas)或SSWG(Simu...自上世纪70年代以来,CO2驱提高采收率技术在油藏工程理念上已形成连续CO2注入、恒定比例C-WAG(Constant Water-Alternating-Gas)注入、梯度/混合-WAG注入(Tapered/Hybrid WAG Injection)以及SWG(Simultaneous Water and Gas)或SSWG(Simultaneous Separated Water and Gas)注入等多种开发模式。CO2之所以成为极具活力的提高采收率注入气,得益于其所特有的超临界流体特征和显著的溶剂化能力。在对CO2主要的具有优势的驱油机理以及国内外典型CO2驱提高采收率油藏工程理念和开发模式分析基础上,结合国内外不同类型油气藏的开发特征,特别是水平井技术、低渗油气藏体积压裂技术的成功应用经验,以及与CCUS(Carbon Capture,Utilization and Storage)一体化的CO2 CCUS-EOR(Carbon Capture,Utilization and Storage-Enhanced Oil Recovery)的综合利用理念,进一步对国内CO2驱提高采收率油藏工程开发模式的发展提出建议,以期能为促进国内CO2驱提高采收率技术的规模化发展提供启示。展开更多
基金support from the Warwick Energy Group and University of Oklahoma to publish this work
文摘Less than 10% of oil is usually recovered from liquid-rich shales and this leaves much room for improvement, while water injection into shale formation is virtually impossible because of the extremely low permeability of the formation matrix. Injecting carbon dioxide（CO2） into oil shale formations can potentially improve oil recovery. Furthermore, the large surface area in organicrich shale could permanently store CO2 without jeopardizing the formation integrity. This work is a mechanism study of evaluating the effectiveness of CO2-enhanced oil shale recovery and shale formation CO2 sequestration capacity using numerical simulation. Petrophysical and fluid properties similar to the Bakken Formation are used to set up the base model for simulation. Result shows that the CO_2 injection could increase the oil recovery factor from7.4% to 53%. In addition, petrophysical characteristics such as in situ stress changes and presence of a natural fracture network in the shale formation are proven to have impacts on subsurface CO2 flow. A response surface modeling approach was applied to investigate the interaction between parameters and generate a proxy model for optimizing oil recovery and CO2 injectivity.
文摘自上世纪70年代以来,CO2驱提高采收率技术在油藏工程理念上已形成连续CO2注入、恒定比例C-WAG(Constant Water-Alternating-Gas)注入、梯度/混合-WAG注入(Tapered/Hybrid WAG Injection)以及SWG(Simultaneous Water and Gas)或SSWG(Simultaneous Separated Water and Gas)注入等多种开发模式。CO2之所以成为极具活力的提高采收率注入气,得益于其所特有的超临界流体特征和显著的溶剂化能力。在对CO2主要的具有优势的驱油机理以及国内外典型CO2驱提高采收率油藏工程理念和开发模式分析基础上,结合国内外不同类型油气藏的开发特征,特别是水平井技术、低渗油气藏体积压裂技术的成功应用经验,以及与CCUS(Carbon Capture,Utilization and Storage)一体化的CO2 CCUS-EOR(Carbon Capture,Utilization and Storage-Enhanced Oil Recovery)的综合利用理念,进一步对国内CO2驱提高采收率油藏工程开发模式的发展提出建议,以期能为促进国内CO2驱提高采收率技术的规模化发展提供启示。
