封闭断层复合油藏压裂井压力动态特征  

Pressure transient characteristics of fractured wells in closed fault composite reservoirs

作　　者：姬安召 王玉风 JI Anzhao;WANG Yufeng(School of Energy Engineering,Longdong University,Qingyang,Gansu 745100,China)

机构地区：[1]陇东学院能源工程学院

出　　处：《油气藏评价与开发》2019年第6期35-41,共7页Petroleum Reservoir Evaluation and Development

基　　金：甘肃省高等学校科研项目“陇东超低渗透油藏降压增注及提高采收率方法研究”（2018A-097）

摘　　要：断层的存在影响复合油藏压力波的传播并且断层的位置影响井底压力变化特征。基于渗流力学和点源函数基本原理,结合镜像原理、压降叠加原则和Laplace积分变换得到Laplace空间复合油藏压裂井线源解。根据压裂井裂缝与储层模型的耦合关系,得到有限导流压裂井井底压力解。利用Stehfest数值反演方法绘制实空间无因次井底压力与压力导数典型特征曲线。研究结果表明:该特征曲线总体上分为七个流动阶段。在早期,无因次井底压力和压力导数曲线位置随无因次裂缝导流能力的增大而降低;镜像井位于内区时,径向流及之后井底压力导数曲线依次呈值为0.5、1和内外区流度比M12的水平线,内区半径越大,内区径向流持续时间越长;镜像井位于外区时,径向流及之后井底压力导数曲线依次呈值为0.5、0.5M12和内外区流度比M12的水平线。The existing faults affects the propagation of pressure waves in the composite reservoirs,meanwhile,the location of faults affects the curves of the bottom hole pressure.Based on the principle of seepage mechanics and point source function,the fractured-well line source solution of fault composite reservoirs in Laplace domain was obtained by image principle,pressure drop superposition principle and Laplace integral transformation.The bottom hole pressure solution of finite-conductivity fractured wells was obtained by coupling fracture of fractured-well and reservoir model.The typical characteristic curves of dimensionless bottom hole pressure and pressure derivative were drawn by Stehfest numerical inversion in the real space.The results showed that the characteristic curve was divided into seven flow stages generally.In the early stage,the position of dimensionless bottom hole pressure and pressure derivative curves decreased with the increase of the fracture conductivity.When the mirror well was located in the inner region,the pressure derivative curves of radial flow and subsequent bottom hole pressure showed horizontal lines of 0.5,1 and fluidity ratio M12 in inner part and outer part,and the larger the inner radius was,the longer the radial flow in the inner zone would be.When the mirror well was located in the outer region,the pressure-derivative curve of radial flow and subsequent bottom hole pressure showed horizontal lines with the value of 0.5,0.5M12 and fluidity ratio of M12 in inner and outer zones.

关 键 词：复合油藏 点源函数 有限导流 封闭断层 压裂井 

分 类 号：TE312[石油与天然气工程—油气田开发工程]