致密气藏变导流能力裂缝压裂水平井不稳定渗流模型  

TRANSIENT FLOW MODEL OF THE FRACTURED HORIZONTAL WELL WITH VARIABLE CONDUCTIVITY FRACTURES IN TIGHT GAS RESERVOIRS

作　　者：高阳[1] 赵超[2] 董平川[2] 高启超[2] 张允[3] 王奇[2] 

机构地区：[1]中国石油新疆油田分公司勘探开发研究院,新疆克拉玛依834000 [2]中国石油大学,北京102249 [3]中国石化石油勘探开发研究院,北京100191

出　　处：《大庆石油地质与开发》2015年第6期141-147,共7页Petroleum Geology & Oilfield Development in Daqing

基　　金：国家重大专项"碳酸盐岩油田开发关键技术"课题五:"复杂介质数值模拟技术与软件"(2011ZX05014-005);国家自然科学基金项目"多尺度离散裂缝油藏有限元数值模拟研究"(51204204)

摘　　要：综合考虑天然裂缝应力敏感和人工裂缝变导流能力的影响,建立了致密气藏多段压裂水平井试井模型。通过将人工裂缝划分为不同微元段,并利用拉普拉斯变换、点源函数法、扰动方法、叠加原理获得了该模型的半解析解。根据新模型绘制了典型无因次压力和压力导数曲线,气体流动可以划分为双线性流、线性流、过渡阶段拟径向流、过渡阶段线性流、早期拟径向流、拟稳态窜流和晚期拟径向流7个阶段。分析了变导流能力裂缝和应力敏感效应对压力和压力导数曲线的影响,变导流能力裂缝主要影响早期流动阶段,应力敏感效应主要影响晚期流动阶段,应力敏感系数越大,在晚期压力和压力导数曲线上翘得越高。该模型对致密气藏更精确地进行试井解释具有一定指导意义。Comprehensively considering the influences of the stress sensitivity of the natural fractures and variable conductivity of the artificial fractures, the well testing model is established for the multi-stage fractured horizontal well in tight gas reservoirs, by means of the artificial fractures, the different micro/infinitesimal-segments and inter- vals are divided, and moreover the semi-analytical solution of the model is obtained with the help of Laplace trans- formation, point source function, perturbation method and superposition principle. According to the typical curves of dimensionless pressure and pressure derivative, the gas flow can be divided into seven flow regimes： bilinear flow, linear flow, intermediate-time pseudoradial flow, intermediate-time linear flow, early-time pseudoradial flow,pseudo-steady cross flow and late-time pseudoradial flow. The influences of the variable conductivity fractures and stress sensitivity effect on the pressure and pressure derivative curves are analyzed, the early flow regimes are mainly influenced by the variable conductivity fractures and the late stage ones are principally affected by the stress sensitivity effect： the bigger the stress sensitivity coefficient is, the higher the curves will ascend. The model possesses a certain guiding significance for more precise well-test interpretation of the tight gas reservoirs.

关 键 词：变导流 应力敏感 致密气藏 压裂水平井 试井 

分 类 号：TE371[石油与天然气工程—油气田开发工程]