特低渗透油层CO_2非混相驱油试验及效果评价  

Experiment and Effect Evaluation of CO_2 Miscible Displacement in Extra-low Permeability Reservoirs

作　　者：汪益宁[1] 吴晓东[1] 张少波[2] 赖枫鹏[3] 滕蔓[4] 

机构地区：[1]石油工程教育部重点实验室(中国石油大学(北京)),北京102249 [2]中石化江汉油田分公司坪北经理部,陕西延安717408 [3]中国地质大学(北京能源学院),北京100083 [4]中海油服油技事业部科技部,河北廊坊065201

出　　处：《石油天然气学报》2013年第4期136-140,169,共5页Journal of Oil and Gas Technology

基　　金：国家油气重大专项(2008ZX05016);国家"863"计划项目(2009AA063404)

摘　　要：特低渗透油藏地层能量低、边底水不活跃、采出程度低,常规水驱开发难度大,如何提高特低渗透油藏的采收率是一项很重要的工作;而特低渗透油田注水开发存在"注入难"的问题,因此注气驱开发特低渗透油藏有显著的优势。与烃类气体相比,CO2有成本低、气源广阔等优势,因此CO2是注气驱优选溶剂之一。介绍了CO2在油藏中增产的驱油机理、条件,完善了预测模型,并分析了CO2驱的现场试验效果。结果表明,虽然在试验区低渗透油藏中CO2驱难以达到混相驱条件,但非混相CO2驱油能使CO2溶入原油后使原油体积膨胀、黏度减低以及降低界面张力、提高驱油效率而达到驱油增产的目的。同时CO2吞吐也在改善中、低渗油藏开发方面展示了广阔的应用前景。In extra-low permeability reservoirs,energy was low,bottom water was active with low recovery percent,thus conventional waterflooding was difficult.How to improve oil recovery in extra-low permeability reservoirs was critical important,but in the reservoir development,there existed the problem of ' difficult injection ',therefore it was an advancement for the reservoir development with gas injection.Compared with hydrocarbon gas,CO 2 was low cost and gas resources were tremendous,therefore CO 2 was one of optimal solvents for gas injection.The oil displacement mechanism and condition of CO 2 stimulation in reservoirs were introduced,and the prediction model was completed,the effect field experiment of CO 2 flooding was analyzed.The result indicates that although the miscible displacement condition could not be obtained by using CO2flooding in the low permeability reservoirs in the tested area,but by using CO2 immiscible displacement,the oil volume could be expanded,its viscosity and interfacial tension could be reduced after CO 2 is dissolved in oil,therefore oil recovery is enhanced for the purpose of improving oil production.At the same time,CO 2 soaking presents its wide prospects of application in improving reservoirs with mid-low permeability.

关 键 词：特低渗透油藏 CO2非混相驱 驱油试验 效果评价 

分 类 号：TE357.45[石油与天然气工程—油气田开发工程]