# Study on Explosive Fracturing Mechanism of Qianjiang Shale Oil
## 1 Introduction
Consequently, bottom shear displacement forms self-supporting fractures without the need for proppant, facilitating smoother hydrocarbon flow and achieving optimal production. Additionally, this technique causes minimal damage to the reservoir and simplifies construction processes. [PERSON] et al. [13] investigated the feasibility of substituting hydraulic fracturing with blasting fracturing in liquid-rich shale formations. Their research indicates that explosive fracturing is more suitable and cost-effective for certain specific applications compared to hydraulic fracturing. However, rock blasting tests are both expensive and time-consuming [12], and theoretical research and numerical simulations are efficient methods to elucidate the mechanisms of rock blasting crack propagation [9; 14; 15; 16]. These approaches facilitate a deeper understanding of the microscopic physical and chemical properties associated with explosive fracturing. [PERSON] et al. [17] introduced an explosive fracturing technique for enhancing shale gas reservoir stimulation. By incorporating the effects of stress wave shock and gas drive from detonation fracturing, utilized numerical simulations to elucidate the propagation mechanisms of fracture initiation. The studies indicated that explosive fracturing can effectively alleviate stress concentration and generate complex fracture networks. [PERSON] et al. [18] conducted a simulation study on low-permeability reservoirs to investigate fracture propagation induced by explosive fracturing. The fractal characteristics of cracks were analyzed, and the fractal dimensions of fractures were examined by fractal geometry theory, which are influenced by the quantity of explosives and confining pressure. The authors recommended that in field operations, the explosive charge should be appropriately matched with confining pressure, employing axial coupling and radial decoupling charge configurations. The magnitude and scope of explosion injuries are largely dictated by the properties of the explosives [19]. The explosion process is fundamentally characterized by an extremely rapid and intense redox reaction between the combustible and oxidizing components [20]. Based on the quantity of oxygen in the explosive, the oxygen balance can be categorized into three distinct scenarios: zero oxygen balance, positive oxygen balance, and negative oxygen balance. The impact of these conditions on formation is primarily reflected in the explosion efficiency, energy release, and environmental safety. To sum up, the development of shale oil reservoirs faces significant technical challenges, including low efficiency in fracture network construction and insufficient reservoir reconstruction. There is an urgent need to explore a new and efficient development technology system. As a promising physical transformation method, explosive fracturing technology offers substantial mechanistic advantages for constructing three-dimensional fracture networks in reservoirs through controlled detonation energy. However, three core issues remain to be addressed. First, compared to traditional hydraulic fracturing, research on the dynamic response of explosive fracturing lags behind, and a comprehensive theoretical model has yet to be established. Second, the variety of explosives and their differing properties result in significant variability in crack propagation patterns. Most importantly, the impact of explosives extends beyond the explosion effect, their environmental impact remains uncertain. Therefore, establishing a detonation fracturing model based on reservoir geology and developing an optimal design methodology for explosive fracturing will be crucial research directions to promote the industrial application of this technology. Based on the geological characteristics of the Qianjiang Depression and utilizing existing three-dimensional seismic data, this study employs the nonlinear finite element program ANSYS LS-DYNA to establish a detonation fracturing model for shale oil reservoirs under explosive loading.