聚合物-表面活性剂二元驱提高采收率机理实验  

Experimental study on the mechanism of enhancing oil recovery by polymer-surfactant binary flooding

作　　者：刘卫东[1,2] 罗莉涛 廖广志 左罗[5] 魏云云[1,2] 姜伟[1] LIU Weidong LUO Litao LIAO Guangzhi ZUO Luo WEI Yunyun JIANG Wei(PetroChina Research Institute of Petroleum Exploration ＆ Development, Langfang 065007, China Institute of Porous Flow and Fluid Mechanics, Chinese Aeademy of Science, Langfang 065007, China School of Environment, Tsinghua University, Beij＇ing 100084, China PetroChina Exploration ＆ Production Company, Beijing 100007, China Sinopec Research Institute of Petroleum Engineering, Beijing 100101, China)

机构地区：[1]中国石油勘探开发研究院,河北廊坊065007 [2]中国科学院渗流流体力学研究所,河北廊坊065007 [3]清华大学环境学院,北京100084 [4]中国石油勘探与生产分公司,北京100011 [5]中国石化石油工程技术研究院,北京100101

出　　处：《石油勘探与开发》2017年第4期600-607,共8页Petroleum Exploration and Development

基　　金：国家科技重大专项(2011ZX05013-006);中国石油科技攻关项目(2014B-1203)

摘　　要：针对新疆油田七中区开发现状,设计聚合物-表面活性剂二元驱的填砂管、天然岩心及微观模型驱油实验,研究二元驱提高采收率机理,为油田现场提供二元驱优化配方。二元驱采收率增幅随着水油黏度比增大而增大,随着界面张力减小而增大。毛细管准数反映二元体系溶液黏度和界面张力的协同效应,应以其为准优化筛选最佳配方。新疆油田七中区二元驱溶液临界黏度比2.5、临界界面张力数量级为1′10-2 m N/m、临界毛细管准数数量级为1′10-3;优选出配方为0.3%KPS-1+1 115 mg/L HPAM,可提高采收率23.96%。二元驱通过聚合物增黏,降低驱替相流度,增加油相流度,使流度比减小,克服了注水指进,增加了吸水厚度,从而提高波及系数,进而启动盲端残余油;通过表面活性剂降低界面张力,降低黏附功,使残余油乳化、剥离、拉丝并易于启动,同时乳状液进一步增加驱替相黏度,在低界面张力和较高黏度下,毛细管准数大幅度提高,从而提高洗油效率,进而启动岛状、柱状及膜状残余油,最终提高了采收率。Aiming at the development situation of the Xinjiang oil field, the mechanism of enhancing oil recovery by the Polymer-Surfactant Binary Flooding （SP Flooding） was studied through SP Flooding sand pack, natural core and micro model experiments, and Optimum SP Flooding formula is provided. The results show that the enhanced oil recovery by the SP Flooding increases with the increase of the viscosity ratio between water and oil or the decrease of the interfacial tension. Capillary displacement ratio can reflect the synergetic effect of viscosity and interfacial tension and help screen out the optimum formula of the SP Flooding. For Qizhong block in Xinjiang Oilfield, where the critical viscosity ratio of SP flooding solution is 2.5, the order of magnitude of the critical interracial tension is 1×10^-2 mN/m, and the order of magnitude of the critical capillary displacement ratio is 1 ×10^-3, the optimum formula of the SP Flooding composed of 0.3% KPS-1＋1 115 mg/L HPAM can enhance the oil recovery by 23.96%. The polymer in the SP Flooding system increases the viscosity of the displacement fluid, accordingly the fluidity of the aqueous phase reduces and that of the oil phase increases, and the resulting decrease of the mobility ratio can control waterflood fingering, make water absorption thickness increase, enhance sweep efficiency and thus activate the residual oil trapped in dead ends. The surfactant decreases interfacial tension, and the resulting decrease of adhesion work makes residual oil emulsified, stripped, wiredrawn and easy to move. In addition, the emulsion liquid further increases the viscosity of the aqueous phase, and with interaction of lower interracial tension and high viscosity of the emulsion liquid, the capillary displacement ratio is greatly enhanced, which in turn improves the oil displacement efficiency by displacing isolated-island, columnar and membranous residual oil, and consequently a higher oil recovery.

关 键 词：聚合物 表面活性剂 二元驱 提高采收率 黏度比 界面张力 毛细管准数 

分 类 号：TE357[石油与天然气工程—油气田开发工程]