摘要
渗吸驱油是裂缝性油藏的有效驱油方式,但渗吸驱油的机理一直没有得到统一的认识,应用相关知识对其进行深入研究,取得以下认识。渗吸有同向渗吸和逆向渗吸之分,地下的渗吸都是同向渗吸。渗吸有平面渗吸和垂向渗吸之分,垂向渗吸比平面渗吸复杂,地下的渗吸都是垂向渗吸。渗吸可分为单边接触式渗吸、双边接触式渗吸和周围接触式渗吸,地下的渗吸为周围接触式渗吸。渗吸有毛细管压力渗吸和浮力渗吸之分,毛细管压力渗吸只能吸水排油,浮力渗吸既可以吸水排油,也可以吸油排水,地下的渗吸都是浮力渗吸。大孔隙中的渗吸速度快,小孔隙中的渗吸速度慢。末端效应会滞留一部分油,降低渗吸效率。在水中加入表面活性剂,可降低末端效应。岩块越大,渗吸采收率就越高,但渗吸时间就越长,可通过实验优化岩块大小及体积压裂的岩石破碎程度。
Oil displacement by imbibition is an effective way of oil recovery in fractured reservoirs.However,there is not a unified recogni tion on its mechanism.In order to clarify the mechanism of imbibition,a study is carried out and some conclusions are obtained in this pa per.Imbibition can be divided into cocurrent imbibition and countercurrent imbibition and the imbibition in reservoirs belongs to cocurrent imbibition.Imbibition can also be classified as horizontal imbibition and vertical imbibition,and vertical imbibition is more complicated than horizontal imbibition.All the imbibitions in reservoirs belong to vertical imbibition.Imbibition also includes one side contact imbibi tion,two side contact imbibition and all side contact imbibition,and the imbibition in reservoirs belongs to all side contact imbibition.Im bibition can also be divided into capillary pressure imbibition and buoyance imbibition.Capillary pressure imbibition can only suck water into rocks and expulse oil,while buoyance imbibition can either suck water into rocks to expulse oil or suck oil into rocks to expulse water.The imbibition in reservoirs belongs to buoyance imbibition.Imbibition in larger pores is faster than that in smaller pores.End effect may retain some oil in rocks,which will decrease imbibition efficiency.Adding surfactant into water can decrease the influence of end effect.The larger the matrix block is,the higher the imbibition recovery efficiency will be,but the longer time will be taken for imbibition.The ma trix block size and reservoir rock fragmentation degree during volumetric fracturing can be optimized through experiments.
作者
李传亮
毛万义
吴庭新
朱苏阳
LI Chuanliang;MAO Wanyi;WU Tingxin;ZHU Suyang(School of Petroleum Engineering,Southwest Petroleum University,Chengdu,Sichuan 610599,China;Testing Branch,Daqing Oilfield Company Limited,PetroChina,Daqing,Heilongjiang 163517,China;Downhole Operation Company,Xibu Drilling Engineering Co.Ltd,CNPC,Karamay,Xinjiang 834000,China)
出处
《新疆石油地质》
CAS
CSCD
北大核心
2019年第6期687-694,共8页
Xinjiang Petroleum Geology
基金
国家科技重大专项(2016ZX05054)
关键词
裂缝性油藏
岩石
基质岩块
孔隙
毛细管
毛细管压力
浮力
渗吸
岩心
驱油
fractured reservoir
rock
matrix block
pore
capillary
capillary pressure
buoyance
imbibition
core
oil displacement
