特低渗油藏活性流体压驱提高采收率机制  

Enhanced oil recovery mechanisms of active fluid high-pressure flooding in ultra-low permeability oil reservoirs

作　　者：孙永鹏 陈超[1] 戴彩丽[1,2] 王传熙 王蓉 赵文勋[3] 张维友[4] 李国良 曾思哲 SUN Yongpeng;CHEN Chao;DAI Caili;WANG Chuanxi;WANG Rong;ZHAO Wenxun;ZHANG Weiyou;LI Guoliang;ZENG Sizhe(School of Petroleum Engineering in China University of Petroleum(East China),Qingdao 266580,China;Key Laboratory of Unconventional Oil&Gas Development(China University of Petroleum(East China)),Ministry of Education,Qingdao 266580,China;Shengli Oilfield,SINOPEC,Dongying 257001,China;School of Energy and Mechanics,Dezhou University,Dezhou 253023,China)

机构地区：[1]中国石油大学(华东)石油工程学院,山东青岛266580 [2]非常规油气开发教育部重点实验室(中国石油大学(华东)),山东青岛266580 [3]中国石化胜利油田分公司,山东东营257001 [4]德州学院能源与机械学院,山东德州253023

出　　处：《中国石油大学学报（自然科学版）》2024年第6期141-148,共8页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：国家重点研发计划项目(2019YFA0708700)。

摘　　要：活性流体压驱是在压驱过程中伴注活性流体段塞的驱替方法。通过试验探究活性流体压驱作用特征,结合界面性质、电性以及毛管数理论等揭示其提高采收率机制。结果表明:水驱后,活性流体压驱可提高采收率4.9%~13.4%,降低注入压差17.6%~51.3%;活性流体分子吸附在油水界面,降低界面张力,增加乳化油滴稳定性,提升微观波及效率,提高特低渗岩心驱油效率;活性流体质量分数从0.05%提高到0.5%,注入速度从0.5 mL/min提高到3 mL/min,室内试验毛管数可提高2个数量级,岩心残余油饱和度降低20.8%;活性流体吸附在岩石孔喉壁面,可减弱多孔介质亲水性,降低压驱过程水相渗流摩阻;压驱存在合适的速度区间,速度过高会增加流体惯性阻力,减弱降压效果;现场试验压驱过程添加活性流体段塞,单井产量可提高0.4 t/d。Active fluid high-pressure flooding refers to a technique of injection of active fluid slugs for enhanced oil recovery(EOR).In this study,the characteristics and EOR mechanisms of the active fluid high-pressure flooding were investigated by conducting a series of experiments combined with interface properties,electrical properties,and capillary number theory.The results indicate that,after water flooding,active fluid high-pressure flooding can increase oil recovery by 4.9%-13.4%,and reduce injection pressure by 17.6%-51.3%.The molecules of the active fluid can be adsorbed at the oil-water interface,which can reduce the interfacial tension,increase the stability of emulsified oil droplets,intensify the microscopic sweep efficiency,and improve oil recovery of ultra-low permeability cores.When the mass concentration of the active fluid is increased from 0.05%to 0.5%the injection flow rate can be increased from 0.5 mL/min to 3 mL/min,the capillary number can be increased by 2 orders of magnitude,and the residual oil saturation can be reduced up to 20.8%.Meanwhile,the adsorption of the active fluids on the pore surface can weaken the hydrophilicity of rock surface and reduce the flow friction of water phase.There is a proper injection rate range for the active fluid high-pressure flooding.Excessive or high injection rate can increase the inertial resistance of the displacement fluid flow and weaken the pressure reduction effect.A field pilot test shows that,with an active fluid slug injection,a daily oil increment of 0.4 t was achieved in a single well.

关 键 词：特低渗油藏 压驱 活性流体 提高采收率 作用机制 降压 

分 类 号：TE319[石油与天然气工程—油气田开发工程]