丘陵油田水驱后注气混相驱可行性实验  

Experimental study on feasibility of gas-injection miscible flooding after water flooding of Qiuling Oilfield

作　　者：肖志朋 刘诗琪 李艳明 韩继凡 安国强 朱永春 李爱芬[2] XIAO Zhipeng;LIU Shiqi;LI Yanming;HAN Jifan;AN Guoqiang;ZHU Yongchun;LI Aifen(Research Institute of Exploration and Development,Tuha Oilfield Company,PetroChina,Hami,Xinjiang,839009,China;School of Petroleum Engineering,China University of Petroleum(East China),Qingdao City,Shandong Province,266580,China)

机构地区：[1]中国石油吐哈油田分公司勘探开发研究院,新疆哈密839009 [2]中国石油大学(华东)石油工程学院,山东青岛266580

出　　处：《油气地质与采收率》2023年第2期68-76,共9页Petroleum Geology and Recovery Efficiency

基　　金：中国石油科技重大专项“新疆油田和吐哈油田勘探开发关键技术研究与应用”子课题七“吐哈油田稀油改善开发效果关键技术研究与应用”(2017E-04-07)。

摘　　要：吐哈盆地丘陵油田地层油为轻质油,油藏的非均质性导致水驱采收率较低,目前已进入高含水期。针对油藏水驱后注气混相驱可行性问题,首先利用细管实验测试了一级分离器气与地层油的混相压力,并优选了能实现混相的混相助剂类型(液化石油气、甲苯、乙二醇丁醚、CO_(2)、富化的天然气)及段塞注入量;其次用油田地层岩心组成的长岩心研究了高含水状态下混相助剂段塞驱+一级分离器气驱+后续水驱的驱油效果。细管实验结果表明,目前地层条件下一级分离器气驱替地层油要实现混相驱需要在注入气前方加入混相助剂段塞。长岩心混相驱油实验结果表明,水驱后气驱可以较大幅度地提高原油采收率,在注入气前方加入混相助剂段塞,驱油效果明显提高,随混相助剂段塞注入量的增加采收率增加;但在地层油中溶解能力稍弱的混相助剂(如CO_(2)、富化的天然气)与溶解能力强的混相助剂(如LPG)的作用规律不同,且并不是注入量越大越好。The oil in place from Qiuling Oilfield in Tuha Basin is light.The heterogeneity of the reservoirs leads to low water flooding recovery,and the reservoir has entered the high water-cut stage.In view of the feasibility of gas miscible flooding after water flooding of the reservoir,the miscible pressure of the first-stage separator gas(PSN gas)and oil in place was tested by a slim tube experiment,and the type of miscible additives(liquefied petroleum gas(LPG),toluene,2-Butoxy ethanol,CO_(2),and enriched natural gas)and the amount of slug injection were optimized.Then,the oil displacement effect of miscible additive slug flooding+PSN gas flooding+subsequent water flooding at the high water-cut stage was studied by using a long core model composed of formation core in the oilfield.The results of the slim tube experiment show that miscible flooding cannot be achieved through the displacement of oil in place by PSN gas under current formation conditions,and it is necessary to add a miscible additive slug in front of injected gas.Long core experiments show that gas flooding after water flooding can greatly enhance the recovery of oil in place.The oil displacement effect is greatly improved by adding a miscible additive slug in front of the injected gas,and the recovery increases with the increment of the injection amount in the miscible additive slug.However,the effect of miscible additives(CO_(2) and enriched natural gas)with weak solubility in oil in place is different from that of miscible additives(LPG)with strong solubility,and higher injection volume may yield a worse effect.

关 键 词：高含水期 混相驱 细管实验 长岩心混相驱油实验 提高采收率 丘陵油田 

分 类 号：TE341[石油与天然气工程—油气田开发工程]