砾岩油藏聚合物驱微观机理研究  

Microscopic Mechanisms of Oil Displacement by Polymer Solution for Conglomerate Reservoir

作　　者：冯慧洁[1] 聂小斌[2] 徐国勇[2] 李荣华[2] 刘卫东[1] 

机构地区：[1]中国石油天然气集团公司中国科学院渗流流体力学研究所,河北廊坊065007 [2]中国石油新疆油田分公司勘探开发研究院,新疆克拉玛依834000

出　　处：《油田化学》2007年第3期232-237,共6页Oilfield Chemistry

摘　　要：应用微观透明仿真刻蚀模型和平面填砂模型研究了砾岩油藏聚合物微观驱油机理。微观模型驱油实验结果表明,聚合物可驱替砾岩油藏喉道和孔道中的剩余油,不能驱出盲端剩余油;油的流动机理,在亲水模型中以剪切夹带为主,而在亲油模型中以拉丝、桥接为主。平面填砂模型聚合物驱实验中明显看到形成油墙,波及体积增加,水驱剩余油明显减少。6种平面填砂模型聚合物驱提高采收率程度不同,最终采收率有较大差别。砾岩模型的最终采收率低于砂岩模型,这是由于砾岩油藏中不流通孔道和盲端较多,残留在其中的油较多。砾岩模型的非均质性越严重,聚合物驱的效果越好。砾岩储层岩心颗粒均匀充填模型的聚驱采收率增值为10.56%,主流线两侧充填密度不同的、主流线充填密度较高的及均匀充填的3个以陶瓷颗粒模拟砾岩颗粒的填砂模型,聚驱采收率分别为9.95%,9.06%及8.87%。聚合物驱仍能用于水驱后的砾岩油藏。图14表1参12。The microscopic mechanisms involved in oil displacement by polymer solution （PS） in conglomerate reservoirs （CRs） are studied on transparent etched micromodels and various planar sand packs. The observations on micromodels show that the residual oil in connected pores and throads of water flooded CRs can be swept out and in dead end pore, can not be swept out easily by flooding PS; the residual oil flow is realized mainly through shearing and entrainment by PS in a water-wet micromodel and through thread forming and bridging of oil films in a weakly oil-wet one. In the course of polymer flooding on a planar conglomerate sand pack, following phenomena are observed： oil bank formation in forefront of PS; enlargement of sweeping areas, and notable reduction of amounts of residual oil after polymer flood. The oil recovery, ultimate and enhanced by polymer flood after water fllood finished is different for six different planar sand packs. The ultimate oil recovery on conglomerate sand packs is lower than that of sandstone sand packs owing to more unconnected pores and dead ends existed in CRs where more residual oil remained after water and polymer fllood. The higher the heterogeneity of a conglomerate sand pack, the more effective the polymer flood in the sand pack is. The enhancement in oil recovery by polymer flood is of 10.56% for a homogeneous reservoir conglomerate sand pack, and is of 9.95%, 9.06%, and 8.87% for three ceramic sand packs of different package structure： with different package density in two sides of the main flowing passage; with higher package density along the main flowing passage; and with homogeneous package density, respectively. Polymer flood is proved to be a useful method of EOR in postwaterflood CRs.

关 键 词：砾岩油藏 微观模型 平面填砂模型 聚合物驱 剩余油 驱油机理 驱油效率 

分 类 号：TE357.46[石油与天然气工程—油气田开发工程]