Numerical Investigation for Three-Dimensional Multiscale Fracture Networks Based on a Coupled Hybrid Model

Energies

Xulin Du¹  Langyu Niu¹  Renyi Cao¹  Linsong Cheng¹  Jun Chen²  Jianchao Cai³ 

[1] College of Petroleum Engineering, China University of Petroleum (Beijing), Beijing 102249, China;Petroleum Engineering School, Southwest Petroleum University, Chengdu 610500, China;State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum (Beijing), Beijing 102249, China;

关键词: multiscale fractures;    three-dimensional fracture visualization;    mimetic Green element method;    reservoir simulation;   

DOI  :  10.3390/en14196354

来源: DOAJ

【 摘 要 】

The mismatching between the multi-scale feature of complex fracture networks (CFNs) in unconventional reservoirs and their current numerical approaches is a conspicuous problem to be solved. In this paper, the CFNs are divided into hydraulic macro-fractures, induced fractures, and natural micro-fractures according to their mode of origin. A hybrid model coupling various numerical approaches is proposed to match the three-dimensional multi-scale fracture networks. The macro-fractures with high-conductivity and wide-aperture are explicitly characterized by a mimetic Green element method-based hierarchical fracture model. The induced fractures and natural micro-fractures that have features of low-conductivity and small-openings are upscaled to the dual-medium grid and enhanced matrix grid through the equivalent continuum-medium method, respectively. Subsequently, some benchmark cases are implemented to confirm the high-precision and high-robustness of the proposed hybrid model that indeed accomplishes accurate modeling of fluid flow in multi-scale CFNs by comparing with commercial software tNavigator^®. Furthermore, an integrated workflow of simulation modeling for multiscale CFNs combined with a field example in Sichuan from China is used to analyzing the production information of fractured horizontal wells in shale gas reservoirs. Compared with the field production data from this typical well, it can be proved that the hybrid model has strong reliability and practicability.

【 授权许可】

Unknown