再论CO2驱提高采收率油藏工程理念和开发模式的发展

Further discussion on reservoir engineering concept and development mode of CO2 flooding-EOR technology

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。

Since the 1970s,CO2 flooding-EOR technology has formed multiple development modes in the concept of reservoir engineering,including continuous CO2 injection,WAG injection with constant proportion,tapered/hybrid WAG injection and SWG/SSWG injection.The reason why CO2 become the injection gas for tertiary oil recovery with great vitality benefits from its supercritical fluid characteristics and remarkable solvation capacity.Based on the analysis of the main oil displacement mechanism of CO2 and the reservoir engineering concept and development mode of typical CO2 flooding-EOR technology at home and abroad in recent years,and considering their development characteristics of different types of reservoirs,especially the successful application of horizontal well technology and low permeability reservoir volume fracturing technology,as well as the comprehensive utilization concept of CO2 CCUS-EOR combined with CCUS concept,further suggestions are put forward for the development of reservoir engineering development mode by CO2 flooding-EOR technology in China,so as to provide enlightenment for further promoting its large-scale development.