Currently

deep shale has become the main position for shale gas exploration and development. As the main battlefield for shale gas development in China

the southeastern region of Chongqing is characterized by unique geological features such as high temperature

bedding development

and strike-slip stress

which limit the high-propagation of hydraulic fractures and severely hinder the stimulation and transformation of shale gas production. Based on this

a large-scale triaxial physical simulation fracturing test on real shale was conducted under the influence of temperature-structure-stress to systematically investigate the influence mechanisms of key parameters

such as temperature

viscosity of fracturing fluid

injection displacement

and in-situ stress difference on the fracturing modification effect. The modification effect of hydraulic fracturing in reservoirs was quantitatively evaluated using the fractal dimensionality calculation method. The results show that under the effect of three control mechanisms

the fracture network morphology after fracturing is characterized by flattening. The thermal shock activated laminae induces fracture steering

which significantly inhibits the expansion of fracture height. The increased stress difference

the use of high-viscosity fracturing fluids

and the construction of high fluid injection displacement can promote fracture expansion across layers. Although the high temperature environment weakens the rupture strength of the rock

it enhances the plasticity characteristics of the rock

resulting in higher extension pressure. The viscosity of the fracturing fluid has a nonlinear regulation on the extension pressure

and the medium viscosity balances the filtering loss effect and viscous resistance to optimize the extension pressure. The analysis of the overall transformation effect of the reservoir shows that high temperature and large-displacement pumping significantly enhance the fractal dimension of the fracture network. The temporary plugging fracturing technique is effective in promoting the volume transformation and improving the complexity of the fracture network. Thermal shock triggers weak tensile extension and generates a large number of microcracks in the bare eye section

and the use of temporary plugging fracturing process can reconstruct the fluid energy distribution and effectively communicate with the unutilized fracture system.