倾斜裂缝水平井非稳态压力模型  

Transient pressure model for horizontal wells with inclined fractures

作　　者：任宗孝[1,2] 吴晓东 屈展[2] 韩国庆[1] 吴小军[1] 王靖惠 

机构地区：[1]中国石油大学石油工程教育部重点实验室,北京102249 [2]西安石油大学石油工程学院,陕西西安710065

出　　处：《石油学报》2017年第9期1059-1065,共7页Acta Petrolei Sinica

基　　金：国家重点基础研究发展计划(973)项目(2015CB250900);CMG Reservoir Simulation Foundation项目;国家自然科学基金项目(No.51674200)资助

摘　　要：由于地层各向异性以及地应力分布不均匀等因素影响,导致水力压裂裂缝与水平井筒之间并不是垂直关系,但目前压裂水平井非稳态压力模型大部分都是在垂直裂缝前提下建立的。为解决现场实际问题,基于Gringarten源函数应用坐标旋转以及坐标平移原理,建立了任意裂缝与水平井筒夹角的分段压裂水平井压力模型。经计算可知分段压裂水平井油藏渗流过程可分为4个流动阶段,即线性流、第一径向流、双径向流以及拟径向流。计算结果表明,裂缝与水平井筒之间的夹角越小,第一径向流持续时间越短,进入拟径向流时间则越早。裂缝穿透比主要影响压裂水平井早期渗流,当裂缝穿透比小于特定值时会出现纵向径向流,裂缝穿透比越低,则纵向径向渗流持续时间越长。裂缝均匀分布且垂直井筒的压裂水平井,开发后期裂缝之间的产量两两相等。但在含有倾斜裂缝的分段压裂水平井中,由于与水平井筒夹角的影响,开发后期每条裂缝的产量互不相等。Due to the anisotropic formation,uneven distribution of geo-stress and other factors,hydraulic fracturing fissures are not vertical to horizontal wellbore.However,the current transient pressure models for fracturing horizontal wells are mainly established under the precondition of vertical fissures.To solve the actual problem,based on the Gringarten source function and coordinate rotation and translation principles,the pressure model was established for the multi-staged horizontal well with arbitrary fracture dip in this study.Through calculation,the reservoir flow process of multi-staged fractured horizontal well can be divided into four flow stages,i.e.,linear flow,the first radial flow,dual radial flow and pseudo radial flow.The calculation indicates that the smaller the angle between the fracture and horizontal wellbore is,the shorter the duration of the first radial flow will be,and the earlier the pseudo radial flow will occur.Fracture penetration ratio mainly affects the early flow of fracturing horizontal well.When the fracture penetration ratio is less than a certain value,longitudinal radial flow will occur;the lower the fracture penetration ratio is,the longer the duration of longitudinal radial flow will be.For the fractured horizontal wells with uniform distribution of fissures and vertical shaft,the production among fractures will be equal in the late development period.However for the multi-staged fractured horizontal wells with inclined fissures,various fractures will correspond to different yields in the late development period due to the influence of dip angle.

关 键 词：倾斜裂缝 坐标变换 水平井 源函数 纵向径向流 

分 类 号：TE312[石油与天然气工程—油气田开发工程]