Numerical Simulation of Fracture Propagation on Proactive Utilization of Stress Interference in the Yingxiongling Shale Oil Reservoir

In the development of shale oil and gas, the tridimensional development model centered around factory drilling, horizontal wells, and hydraulic fracturing has been widely adopted. This development model inevitably triggers both positive and negative hydraulic fracturing interference as well as production interference. Especially during the hydraulic fracturing process, actively controlling stress interference can effectively utilize these interferences to generate positive effects, thereby increasing the complexity of fractures and enhancing the efficiency of oil and gas extraction. This paper develops an analytical expression mathematical model of a spatial stress field, which is used to explore how the coupled design of different well spacings and fracturing layouts proactively affects the spatial stress field. Based on the geoscience & engineering integration software platform, this study combines fracture propagation simulation with finite element numerical simulation of the stress field, clarifying how to proactively utilize and control stress interference. The research indicates that strengthening well interference and implementing staggered fracturing strategies can promote the formation of complex fracture networks at distant ends, while effectively inhibiting excessive extension of the main fractures towards neighboring wells. Through the deployment of a tridimensional well network, and the coupled design of well spacing and fracture spacing, an overall optimization and utilization of the spatial stress field can be achieved. 1. INTRODUCTION In the global oil and gas industry's exploration and development sector, there is a gradual shift from conventional oil and gas, which accounts for 20% of the total oil and gas resources, to unconventional oil and gas resources, which make up 80% (Zou et al., 2023). As the first country to achieve commercial development of shale oil globally, the United States has effectively driven cost reduction and efficiency improvements through the scaled-up development of shale oil via "super well factories" (Guo et al., 2023). China's shale oil resources are extremely abundant. According to exploration assessments, the recoverable resources are estimated to be about 5 billion tons. However, compared to the marine shale oil in North America, China's continental shale oil exhibits some unique geological characteristics, such as strong reservoir heterogeneity, thin individual layer thickness, and rapid changes in lithology and facies (Li et al., 2023). These characteristics make the use of a tridimensional development strategy particularly important for the overall mobilization of the reservoir.