A semi-analytical model for coupled flow in stress-sensitive multi-scale shale reservoirs with fractal characteristics

作     者：Qian Zhang Wen-Dong Wang Yu-Liang Su Wei Chen Zheng-Dong Lei Lei Li Yong-Mao Hao Qian Zhang;Wen-Dong Wang;Yu-Liang Su;Wei Chen;Zheng-Dong Lei;Lei Li;Yong-Mao Hao

作者机构：Key Laboratory of Unconventional Oil&Gas Development(China University of Petroleum(East China))Ministry of EducationQingdao266580ShandongChina School of Petroleum EngineeringChina University of Petroleum(East China)Qingdao266580ShandongChina Shale Oil Development BranchChangqing Oilfield CompanyPetroChinaQingyang745708GansuChina PetroChina Research Institute of Petroleum Exploration&DevelopmentBeijing100083China 

出 版 物：《Petroleum Science》 (石油科学（英文版）)

年 卷 期：2024年第21卷第1期

页      面：327-342页

核心收录：

学科分类：0820[工学-石油与天然气工程] 08[工学] 082002[工学-油气田开发工程] 

基　　金：This study was supported by the National Natural Science Foundation of China(U22B2075 52274056 51974356) 

主　　题：Multi-scale coupled flow Stress sensitivity Shale oil Micro-scale effect Fractal theory 

摘      要：A large number of nanopores and complex fracture structures in shale reservoirs results in multi-scale flow of oil. With the development of shale oil reservoirs, the permeability of multi-scale media undergoes changes due to stress sensitivity, which plays a crucial role in controlling pressure propagation and oil flow. This paper proposes a multi-scale coupled flow mathematical model of matrix nanopores, induced fractures, and hydraulic fractures. In this model, the micro-scale effects of shale oil flow in fractal nanopores, fractal induced fracture network, and stress sensitivity of multi-scale media are considered. We solved the model iteratively using Pedrosa transform, semi-analytic Segmented Bessel function, Laplace transform. The results of this model exhibit good agreement with the numerical solution and field production data, confirming the high accuracy of the model. As well, the influence of stress sensitivity on permeability, pressure and production is analyzed. It is shown that the permeability and production decrease significantly when induced fractures are weakly supported. Closed induced fractures can inhibit interporosity flow in the stimulated reservoir volume (SRV). It has been shown in sensitivity analysis that hydraulic fractures are beneficial to early production, and induced fractures in SRV are beneficial to middle production. The model can characterize multi-scale flow characteristics of shale oil, providing theoretical guidance for rapid productivity evaluation.