乳液在多孔介质中的微观赋存特征及调驱机理  

Pore-scale investigation on occurrence characteristics and conformance control mechanisms of emulsion in porous media

作　　者：苏航 周福建 刘洋[3] 高亚军 成宝洋 董壬成 梁天博 李俊键 SU Hang;ZHOU Fujian;LIU Yang;GAO Yajun;CHENG Baoyang;DONG Rencheng;LIANG Tianbo;LI Junjian(State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum,Beijing 102249,China;MOE Key Laboratory of Petroleum Engineering,China University of Petroleum,Beijing 102249,China;China Petroleum Engineering&Construction Corp.Beijing Company,Beijing 100023,China;CNOOC Research Institute Co.,Ltd.,Beijing 100028,China;University of Texas at Austin,Austin TX78712,USA)

机构地区：[1]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [2]中国石油大学(北京)教育部重点实验室,北京102249 [3]中国石油工程建设有限公司北京设计分公司,北京100023 [4]中海油研究总院有限责任公司,北京100028 [5]美国得克萨斯大学奥斯汀分校,奥斯汀TX78712,美国

出　　处：《石油勘探与开发》2021年第6期1241-1249,共9页Petroleum Exploration and Development

基　　金：国家科技重大专项(2017ZX05009-005-003);国家自然科学基金资助面上项目(52174045);中国工程院战略咨询项目(2018-XZ-09);中国石油天然气集团有限公司-中国石油大学(北京)战略合作科技专项(ZLZX2020-01)。

摘　　要：利用微计算机断层扫描技术(Micro-CT)同步岩心驱替实验直观呈现乳液在人造砂岩岩心中的赋存状态,并通过一系列定量化图像处理方法,对孔隙中乳液的赋存特征以及调驱机理进行评价。实验研究表明:①乳液在岩心中呈球形分布,其球形度与剩余油具有显著差异,可以将球形度作为特征参数对乳液进行识别;②特定尺寸的乳液更倾向于在特定尺寸的孔隙中赋存,当乳液体积小于孔隙占有率下限与对应孔隙体积乘积时将无法有效滞留在孔隙中发挥调剖作用,在进行乳液调驱时,需要根据储集层孔隙分布设计合理的乳液粒径;③实验岩心条件下,通过乳液调驱作用,后续水驱结束后可将动用孔隙数量比例从水驱的23.1%提高至59.3%,并将平均孔隙驱油效率从22.9%提升至75.8%;④乳液调驱后,簇状剩余油和滞留乳液中的油相是后续提高采收率的主要动用目标。Microscopic computed tomography(Micro-CT)is used to visualize microscopic flow in sandstone core samples during emulsion flooding.The images obtained during the experiment are processed quantitatively with a series of methods to evaluate the occurrence characteristics and oil recovery enhancement mechanisms of emulsion.(1)The emulsion is distributed in the cores in spherical shape,and its sphericity is significantly different from that of the remaining oil.Sphericity can be taken as a characteristic parameter to identify emulsion.(2)The emulsion with specific size prefers to stay in pores with matching sizes;when the emulsion volume is smaller than the product of the lower limit of pore occupancy and the corresponding pore volume,it will not be able to effectively trap in the pore to achieve conformance control.In the process of emulsion displacement designing,we need to design emulsion with suitable particle size according to the pore distribution of the reservoir.(3)Mobilization ratio of the pores can be increased from 23.1%to 59.3%by emulsion flooding after subsequent water flooding,and the average oil displacement efficiency at the pore-scale can be increased from 22.9%to 75.8%under the test conditions;(4)After emulsion flooding,the clustered remaining oil and the oil phase in the trapped emulsion are the main targets for further EOR.

关 键 词：MICRO-CT 乳液驱 赋存特征 调驱机理 提高采收率 

分 类 号：TE357[石油与天然气工程—油气田开发工程]