非均质油藏聚合物驱提高采收率机理再认识  

EOR mechanisms of polymer flooding in a heterogeneous oil reservoir

作　　者：卢祥国[1] 曹豹 谢坤[1] 曹伟佳[1] 刘义刚 张云宝[1,2] 王晓燕 张杰[3] LU Xiangguo;CAO Bao;XIE Kun;CAO Weijia;LIU Yigang;ZHANG Yunbao;WANG Xiaoyan;ZHANG Jie(Key Laboratory of Enhanced Oil and Gas Recovery of Ministry of Education,Northeast Petroleum University,Daqing 163318,China;Oil Production Technology Research Institute of Tianjin Branch of CNOOC,Tianjin 300450,China;Oil Production Technology Research Institute of Dagang Oilfield of CNPC,Tianjin 300280,China)

机构地区：[1]东北石油大学提高油气采收率教育部重点实验室,黑龙江大庆163318 [2]中海石油(中国)有限公司天津分公司采油工艺研究所,天津300450 [3]中国石油大港油田公司采油工艺研究院,天津300280

出　　处：《石油勘探与开发》2021年第1期148-155,共8页Petroleum Exploration and Development

基　　金：国家“十三五”油气重大专项课题(2016ZX05058-003-010);国家自然科学基金面上项目(51574086);中国博士后创新人才支持计划(BX20190065)。

摘　　要：以大庆、大港、长庆等油田的储集层岩石和流体为模拟对象,探讨了非均质油藏聚合物驱提高采收率的机理和技术途径,通过对比“等黏度”和“等浓度”条件下普通聚合物溶液、甘油、“片-网”结构聚合物溶液和非均相弱凝胶等的驱油效果,论证了聚合物类驱油剂黏度与驱油效果间的关系,提出了改善聚合物驱效果的方法。研究表明,聚合物在多孔介质内因滞留作用进而扩大注入水波及体积是聚合物驱提高采收率主要机理,而聚合物类驱油剂黏度与驱油效果不存在正相关性,具有“片-网”结构的聚合物虽然增黏能力较强,但与储集层岩石孔喉结构的配伍性较差,其可注入性和抗剪切性较差;非均相弱凝胶体系在多孔介质内具有较强的吸附、捕集作用,容易在储集层岩石孔隙内滞留,在高渗透层(区域)能够建立有效的渗流阻力,与具有“等黏度”或“等浓度”的聚合物溶液相比,扩大波及体积能力更强;长时间注入聚合物类驱油剂,势必会导致吸液剖面反转,大大降低聚合物驱开发效果,采用“高滞留”与“低滞留或不滞留”驱油剂交替注入,可进一步改善聚合物类驱油剂驱油效果。Taking reservoir rocks and fluids of the Daqing,Dagang and Changqing oilfields as research objects,the EOR mechanisms and technical approach of polymer flooding were discussed.By comparing the displacement performances of ordinary polymer,glycerol,polymer in“sheet-net”structure and heterogeneous weak gel at the same viscosity and concentration,the relationship between the viscosity of polymer displacement agents and displacement performance was demonstrated,and the method of improving polymer flooding effect was worked out.The main mechanism of polymer flooding to increase oil recovery is the swept volume expansion of water injection due to polymer retention in porous media.The viscosity of polymer agents has no positive correlation with polymer flooding effect.Although polymer of“sheet-net”structure has strong capacity in increasing viscosity,it has poor compatibility with pore throat structure of reservoir rock,low injectivity and low shear resistance.Heterogeneous weak gel system has higher adsorption and capture capacity in porous media,which is easy to retain in porous media,and can effectively establish seepage resistance in high permeability layers(zones).Compared with polymer solutions with the same viscosity or concentration,it has stronger ability to expand swept volume.Long term injection of polymer flooding agents will inevitably lead to fluid entry profile reversal,and thus worsening of polymer flooding effect.Alternate injection of high retention and low or non-retention displacement agents can further improve the displacement effect of polymer flooding agents.

关 键 词：非均质油藏 聚合物驱 驱油效果 提高采收率 波及体积 改善方法 

分 类 号：TE327[石油与天然气工程—油气田开发工程]