致密油藏体积压裂水平井半解析渗流模型  

Semi-analytical seepage model for horizontal wells with volume fracturing in tight oil reservoirs

作　　者：任宗孝[1] 吴晓东[1] 金岗 李华昌[3] 王瑞河[1] 马高强[1] 

机构地区：[1]中国石油大学石油工程教育部重点实验室 [2]中石油阿姆河天然气勘探开发(北京)有限公司 [3]中国石化集团国际石油工程有限公司

出　　处：《石油钻采工艺》2016年第5期633-639,共7页Oil Drilling & Production Technology

基　　金：国家重点基础研究发展973计划项目"陆相致密油高效开发基础研究"(编号:2015CB250900);国际科技研究项目"CMG Reservoir Simulation Foundation"

摘　　要：由于非常规油藏特殊地质条件,导致在进行大规模水力压裂过程中形成了复杂的裂缝网络,复杂缝网的出现导致油藏渗流规律发生变化。基于体积源函数在准确描述复杂缝网形态的基础上,考虑复杂缝网内渗透率,建立了致密油藏体积压裂水平井半解析渗流模型,模型结果的正确性得到了油藏数值模拟的验证。计算结果表明,含有复杂缝网的油藏渗流过程可以分为6个流动阶段:线性流、供给流动、过渡流、双径向流、晚期径向流以及边界控制流动。缝网渗透率主要影响早期线性流和供给流动,次生裂缝渗透率对供给流动影响较大;过渡流、双径向流以及晚期径向流动受复杂缝网几何尺寸影响较大。该模型为预测体积压裂水平井的产能、认识体积压裂水平井渗流规律以及评价体积压裂效果提供了一种非常有用的方法。Due to special geologic conditions, complex fracture network may be created in unconventional oil reservoir during large-scale hydraulic fracturing, which may lead to changes in seepage pattern in such reservoirs. Based on accurate description of such complex fracture network using volumetric source function, semi-analytical seepage model for horizontal wells stimulated by volume fracturing in tight oil reservoir has been built with consideration of permeability in the fracture network. Modeling results coincide well with numerical simulation results for these reservoirs. Calculation results show seepage flow in oil reservoirs with complex fracture network can be classified into following 6 phases： linear flow, supplying flow, transitional flow, dual radial flow, late-stage radial flow and border-controlled flow. Permeability in the fracture network may predominantly affect linear flow and supplying flow in early stages, while permeability in secondary fractures may dramatically affect supplying flow. At the same time, transitional flow, dual radial flow and late-stage radial flow are significantly subject to impacts of geometric sizes of complex fracture networks. The newly developed model may be applied to predict productivity, highlight seepage pattern and assess performances of horizontal wells stimulated by volume fracturing.

关 键 词：致密油藏 体积压裂 水平井 体积源函数 渗流阶段划分 

分 类 号：TE348[石油与天然气工程—油气田开发工程]