CO_(2)/表面活性剂复合驱油提高采收率研究  

Study on CO_(2)/Surfactant Composite Flooding for Enhanced Oil Recovery

作　　者：吴俊峰[1] 徐盼龙 杨展华 赵旭[1] WU Jun-feng;XV Pan-long;YANG Zhan-hua;ZHAO Xv(No.7 Oil Production Plant of Changqing Oil and Gas Branch of CNPC,Qingyang Gansu 457000,China)

机构地区：[1]中国石油天然气集团公司长庆油气分公司第七采油厂,甘肃庆阳457000

出　　处：《当代化工》2023年第4期993-996,1001,共5页Contemporary Chemical Industry

基　　金：国家科技重大专项课题,大型油气田及煤层气开发(项目编号:2020ZX05012-001)。

摘　　要：随着油田中大量轻烃采出,CO_(2)与地层原油的极性差异变大,萃取原油效果变差,并且由于黏性指进和过早突破的问题,开发效果越来越不理想。基于此,初选6种目前常用的驱油表面活性剂,进行溶解度、降黏实验以及耐盐、耐温实验,对表面活性剂进行筛选和评价。通过细管驱替实验测定地层压力下纯CO_(2)驱和复合驱的驱油效率,评价复合驱提高采收率的可行性。实验结果表明:表面活性剂AES能大大降低原油黏度,有效改善其流动性,并能溶于超临界CO_(2),具有良好的两亲性,同时化学稳定性也符合生产要求,可作为驱油剂使用;在不高于混相压力下,以0.08 PV的表面活性剂段塞注入地层,在各个压力点下,复合驱的驱油效率都比纯CO_(2)驱要高,证明了复合驱提高采收率的可行性,原油MMP降低了5 MPa,使得油田的CO_(2)近混相驱甚至混相驱具备可能性。With the production of a large amount of light hydrocarbons in the oilfield,the polarity difference between CO_(2) and formation crude oil becomes larger,the extraction effect of crude oil becomes worse,and the development effect becomes less and less ideal due to the problems of viscosity fingering and premature breakthrough.Based on this,six kinds of commonly used oil displacement surfactants were initially selected,and the solubility,viscosity reduction experiments,salt and temperature resistance experiments,the characteristics of crude oil in the study area and the requirements of oil displacement agents for tertiary oil recovery were used to screen and evaluate surfactants.The oil displacement efficiency of pure CO_(2) flooding and combined flooding under formation pressure was measured by thin tube displacement experiments,and the feasibility of enhanced oil recovery of combined flooding was evaluated.The experimental results showed that the surfactant AES could greatly reduce the viscosity of crude oil,effectively improve its fluidity,and could be dissolved in supercritical CO_(2),had good amphiphilicity,and the chemical stability also met the production requirements,and could be used as an oil displacement agent.When a 0.08 PV surfactant slug was injected into the formation at no higher than the miscible pressure,the oil displacement efficiency of composite flooding was higher than that of pure CO_(2) flooding at each pressure point,indicating that composite flooding was feasible to enhance oil recovery,the MMP of crude oil was reduced by 5 MPa,which made it possible for CO_(2) near-miscible flooding or even miscible flooding in the oilfield.

关 键 词：表面活性剂 CO_(2) 复合驱油体系 采收率 性能评价 

分 类 号：TQ423[化学工程]