A Study on Three-Dimensional Multi-Cluster Fracturing Simulation under the Influence of Natural Fractures  
[PERSON]  
1 Chongqing Shale Gas Exploration and Development Co., Ltd., Chongqing 401120, China; 1 [EMAIL_ADDRESS]  
[PERSON]  
2 State Key Laboratory of Geomechanics and Geotechnical Engineering, Wuhan Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China; [EMAIL_ADDRESS] (M.W. ); [EMAIL_ADDRESS] (Y.G.) [PERSON]  
3 Shale Gas Research Institute of PetroChina Southwest Oil & Gas Field Company, Chengdu 610051, China; [EMAIL_ADDRESS]  
[PERSON]  
2 State Key Laboratory of Geomechanics and Geotechnical Engineering, Wuhan Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China; [EMAIL_ADDRESS] (M.W. ); [EMAIL_ADDRESS] (Y.G.) [PERSON]  
5 Shatel Gas Research Institute of PetroChina Southwest Oil & Gas Field Company, Chengdu 610051, China 5 [EMAIL_ADDRESS]  
[PERSON]  
6 Sichuan Key Laboratory of Shale Gas Evaluation and Exploitation, Chengdu 610051, China 61  
resources [1]. Deep shale oil and gas resources at depths of over 3500 m account for a huge proportion of the current energy structure. Optimizing the construction and exploitation of deep oil and gas resources through construction techniques such as multi-cluster fracturing is a necessary means to achieve efficient exploitation of deep oil and gas resources [2]. It is noteworthy that deep oil and gas reservoirs are often found in high-stress environments with complex fracture characteristics (discontinuous structures such as bedding, joints, and fractures formed by the sedimentation and tectonic processes of deep reservoirs) [3], which significantly affects the effectiveness of reservoir transformation [4; 5]. Therefore, an in-depth exploration of the impact of natural fractures on the multi-cluster fracturing construction technology of deep oil and gas reservoirs is of great significance for the development of deep oil and gas resources. Both theoretical solutions and indoor tests can be used to study the propagation of fracturing fractures. Over the years, various theoretical solution models such as the KGD model, PKN model, and Penny model, among others, have been established through theoretical derivations [2; 6; 7; 8; 9; 10]. Meanwhile, some scholars have found in their research that there may be multiple control mechanisms in the reservoir due to the influence of fracture toughness and the fracturing injection rate of reservoir rocks. Therefore, a theoretical model for artificial fracture propagation in reservoirs under the influence of comprehensive parameters such as viscosity control and toughness control has been derived. However, the reservoir rock is often assumed to be a homogenous and isotropic medium in theoretical derivation, meaning that the impact of naturally occurring fractures and the growth of numerous fracture groups cannot be considered. Of course, scholars have also conducted extensive physical simulation research using laboratory experimental methods [5; 11; 12; 13; 14; 15]. In the initial stages, conventional triaxial loading systems were predominantly utilized, focusing on the influence of reservoir geo-stress by controlling surrounding rock and axial pressure. However, real reservoirs typically experience stress conditions under true triaxial stress, prompting some researchers to develop authentic triaxial experimental setups to simulate fracturing from single to multiple clusters. Through these experiments, they have been able to glean insights into the propagation patterns of artificial fractures. Nevertheless, replicating the impact of natural fractures in laboratory settings proves to be a challenge, and further examination is warranted for the transferability of specimen-scale results to reservoir-scale scenarios. Consequently, there is a growing interest in the simulation analysis of reservoir fracturing at the reservoir scale [16; 17].