延长油田特低渗油藏适度温和注水方法与应用  

Method of moderate water injection and its application in ultra-low permeability oil reservoirs of Yanchang Oilfield, NW China

作　　者：王香增[1] 党海龙 高涛 WANG Xiangzeng;DANG Hailong;GAO Tao(Shaanxi Yanchang Petroleum(Group)Corp.Ltd.,Xi’an 710075,China)

机构地区：[1]陕西延长石油(集团)有限责任公司,西安710075

出　　处：《石油勘探与开发》2018年第6期1026-1034,共9页Petroleum Exploration and Development

基　　金：陕西省科技统筹创新项目"延长难采储量有效动用开发技术研究"(2016KTCL01-12)

摘　　要：为解决裂缝性特低渗油藏注水开发水窜、水淹问题,提高水驱开发效果,以延长油田南部地区长8油藏为研究对象,建立了裂缝-基质动态渗吸室内实验评价方法,确定了制约渗吸效果的关键因素,获得了渗吸速度的数学表达式,建立了考虑渗吸-驱替双重作用的渗流数学模型,确定了研究区最佳注采参数。研究表明,水驱油过程存在使渗吸驱油效率达到最高的最佳驱替速度,且随着渗透率的降低最佳驱替速度变小;储集层品质指数和岩石水相润湿指数越大,渗吸驱油效率越高,而初始含水饱和度、油水黏度比越大,渗吸驱油效率越低;延长油田南部长8特低渗油藏最佳注采比为0.95,含水率95%时预测的水驱采出程度为17.2%,较常规注水(注采比1.2)增加2.9个百分点。充分发挥渗吸-驱替双重作用的"适度温和"注水技术可显著提高裂缝性特低渗油藏注水开发效果。To explore the method of improving development effect and solving the problem of water breakthrough and water out for ultralow permeability fractured reservoirs,an indoor evaluation method of dynamic imbibition for fracture-matrix system was established taking the Chang 8 reservoir in southern Yanchang Oilfield as a research target.Key factors for the imbibition effect were obtained,an imbibition’s rate expression was obtained,a model considering the double effects of imbibition-displacement was built and optimal injection and production parameters for the research area were obtained as well.The results show that an optimum displacement rate that maximizes the oil displacement efficiency exists in the water displacing oil process,and the optimal displacing rate becomes smaller as the permeability decreases.The imbibition displacement efficiency increases as the reservoir quality index and water wettability index of rock become bigger.But the larger the initial water saturation or oil-water viscosity ratio is,the smaller the imbibition displacement efficiency is.The optimal injection-production ratio for the Chang 8 reservoir of southern Yanchang Oilfield is 0.95,and the predicted recovery is 17.2%when the water cut is 95%,it is 2.9%higher than the recovery of conventional injection-production ratio 1.2.By using the moderate water injection technique based on the double effects of imbibition-displacement mechanism,the water injection development effect for the ultra-low permeability fractured reservoirs can be improved significantly.

关 键 词：特低渗油藏 裂缝性油藏 注水开发 渗吸 驱替 水驱采收率 延长油田 

分 类 号：TE33[石油与天然气工程—油气田开发工程]