考虑表面扩散的页岩气藏多级压裂水平井数值模拟  

Numerical Simulation of Multi-stage Fracturing Horizontal Well in Shale Gas Reservoir Considering Surface Diffusion

作　　者：吴明录[1] 丁明才 姚军[1] 徐思南 李轩 WU Minglu;DING Mingeai;YAO Jun;XU Sinan;LI Xuan(Faeuhy of Petroleum Engineering, China University of Petroleum （East China） , Qingdao 266580, Shandong,Chin)

机构地区：[1]中国石油大学(华东)石油工程学院,山东青岛266580

出　　处：《西安石油大学学报（自然科学版）》2018年第3期29-36,共8页Journal of Xi’an Shiyou University（Natural Science Edition）

基　　金：长江学者和创新团队发展计划资助项目(IRT1294);国家高技术研究发展计划(863计划)资助项目(2013AA09A215)

摘　　要：考虑页岩气黏性流动、Knudsen扩散、吸附气表面扩散和解吸等渗流机理,建立了页岩气在基质孔隙中的渗流数学模型;并在此基础上建立了页岩气藏多级压裂水平井渗流数学模型,该模型包含由基质、水力诱导裂缝和水力裂缝组成的压裂改造区(SRV)和只含基质的未改造区(USRV)。采用嵌入式离散裂缝模型和拟牛顿迭代法求解,得到页岩气藏压力分布和页岩气累积产量,并分析了参数敏感性。在纳米级孔隙中,吸附气表面扩散是页岩气主要渗流机理;而且孔隙半径越小,吸附气表面扩散对页岩气累积产量影响越大。The seepage model of shale gas in matrix pore was established based on the seepage mechanisms of shale gas, including viscous flow, Knudsen diffusion,and the surface diffusion and desorption of adsorbed gas. Based on this,the seepage model of a nmlti-stage fracturing horizontal well in shale gas reservoir was established, in which the SRV zone composed of matrix, induced fractures and hydraulic fractures and the USRV zone only composed of matrix are included. The model was solved by using the embedded discrete fracture model and the quasi Newton iteration method, the pressure distribution and the cumulative shale gas production of the shale gas horizontal well were obtained, and the sensitivity of parameters is analyzed. The research shows that the surface diffusion of adsorbed gas in nano-pores is the main seepage mechanism of shale gas,and the smaller the pore radius, the greater the effect of the surface diffusion of adsorbed gas on the cumulative production of shale gas well.

关 键 词：页岩气 渗流机理 吸附气 表面扩散 

分 类 号：TE319[石油与天然气工程—油气田开发工程]