大庆长垣特高含水期表外储层独立开发方法  

An independent development method of low permeability oil thin layers with extreme high water cut in Changyuan Structure,Daqing oilfield

作　　者：高大鹏[1,2] 叶继根[2] 李奇[1] 石成方[2] 胡云鹏[2] 侯绍继 纪淑红[2] 黄磊[2] 

机构地区：[1]中国科学院力学研究所,北京100190 [2]中国石油勘探开发研究院,北京100083

出　　处：《石油与天然气地质》2017年第1期181-188,共8页Oil & Gas Geology

基　　金：国家科技重大专项(2011ZX05010-002)

摘　　要：物性和含油性差的表外储层已经成为大庆长垣特高含水阶段水驱挖潜的主要对象,然而常规的井网加密、分层注水等方法开发效果较差。为此,结合表外储层发育特征和分层压裂工艺,提出了表外储层独立开发方法。根据油水井射孔层位和表内、表外储层空间分布特征,设计了"以水定油"和"以油定水"两种独立开发模式,采用多层人造浇铸岩心开展了水驱物理模拟实验,比较了两种模式的采出程度随注入量的变化特征,推导了考虑启动压力梯度和浅层水平压裂裂缝的分层压裂直井产能公式,计算分析了表外储层独立开发的技术政策界限。研究表明:长垣表外储层独立开发"以油定水"模式优于"以水定油"模式,技术极限井距和经济极限厚度分别为228 m和2 m左右。随着表外储层厚度占总射孔厚度比例的增大,采收率先下降后保持平稳,最后又快速上升。矿场应用表明:表外储层独立开发平均单井日产油量3.7 t,开发效果明显优于三次加密。Low permeability thin oil layers have become the main object for waterflooding production in extreme high water cut stage in Changyuan area,Daqing oil field.However,conventional methods,such as well pattern infilling and layer-specific water injection,could get no satisfying effect.Therefore,a method of independent development of low permeability thin oil layers is put forward by taking into account features of these low permeability thin oil layers and technologies of layered hydraulic fracturing.Two kinds of development models are suggested,and one of the models designs how water wells perforate reservoir zones depending on the number and pattern of oil wells that perforate low permeability thin oil layers only,the other one designs how oil wells perforate zones depending upon the number and patterns of water wells that perforate low permeability thin oil layers only.Then,the recovery of these two modes are compared by waterflooding physical simulation experiments with multi-layer artificial casting cores.The productivity model of layered fractured vertical well is deduced considering the threshold pressure gradient and horizontal fractures in shallow reservoirs,and the technology limits are calculated and analyzed for the independent development of low permeability thin oil layers.The results show that the first model will get more recovery than the second one,and the technical limit of spacing is about 228 m,the economic limit of thickness is 2 m.With the increasing of low permeability thin oil layers thickness to total perforated thickness ratio,recovery declines firstly and then remained stable,and rises rapidly finally.Field application shows that the average well production is 3.7 tons/day under the independent development of low permeability thin oil layers,its development effect is better than tertiary well pattern infilling.

关 键 词：水驱纵向波及效率 水平裂缝 分层压裂 特高含水 表外储层 水驱挖潜 大庆长垣构造 

分 类 号：TE348[石油与天然气工程—油气田开发工程]