Productivity analysis of a fractured horizontal well in a shale gas reservoir based on discrete fracture network model  

作　　者：Yu-long Zhao Nan-ying Li Lie-hui Zhang Rui-han Zhang 

机构地区：[1]State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, China [2]Southwest Oil and Gas Branch, SINOPEC, Chengdu 610041, China

出　　处：《Journal of Hydrodynamics》2019年第3期552-561,共10页水动力学研究与进展B辑（英文版）

基　　金：the National Naturel Science Foundation of China(Key Program)(Grant No.51534006);the National Natural Science Foundation of China(Grant Nos.51704247,51874251);the PetroChina Innovation Foundation(Grant No.2018D-5007-0218);the 111 project(Grant No.D18016).

摘　　要：The treatment of horizontal wells with massive hydraulic fracturing technology is important for the economical development of shale gas reservoirs, but sometimes is complex because of the induced fractures during the fracturing process. The studies of the fluid flow characteristics in such formations are rare. In this study, a numerical method based on a finite element method (FEM) is developed for the productivity analysis of a horizontal well in a shale gas reservoir with complex fractures. The proposed method takes into account the adsorbed gas and the complex hydraulic fracture branches. To make the problem more tractable, the dimension of the fracture system is reduced from 2-D to 1-D based on the discrete fracture network (DFN) model. The accuracy of the new method is verified by comparing its results with those obtained by the Saphir commercial software. Finally, the productivity of the fractured horizontal wells in shale gas reservoirs with complex fractures systems is evaluated and analyzed. Results show that if a well is produced with a constant bottomhole pressure, the well productivity is much increased due to the existence of fracture branches that can increase the stimulated reservoir volume (SRV). In addition, the number of hydraulic fractures (Nf) and the fracture halMengths (Lf) have an important influence on the well's productivity. The larger the values of Nf,Lf,the greater the well productivity will be. The existence of adsorbed gas can markedly improve the well productivity, and the greater the Langmuir volume, the greater the productivity will be. The conclusions drawn by this study can provide a guidance for the development of unconventional shale gas reservoirs.

关 键 词：Fractured HORIZONTAL WELL discrete fracture network (DFN) MODEL finite element method (FEM) PRODUCTIVITY analysis SHALE gas RESERVOIR 

分 类 号：O3[理学—力学]