The geometry size of fractures and the time of phase change in chemical fracturing by self-generated solid are closely related to the temperature field of cracks. Based on the pseudo-three-dimensional crack propagation model

a coupled temperature field model of the cracks is established. And its coupling solution is carried out. This model takes into account the variation of viscosity of self-generated solid chemical fracturing fluids with temperature

and applies homogeneous treatment to two-phase fracturing fluids. The practical calculation results show that mutual influence among temperature field

viscosity of fracturing fluid system and fracture geometry. The increase of non-phase-change fracturing fluid accumulation with low specific heat capacity and high heat conduction coefficient is conducive to the improvement of the temperature in the cracks and the rapid phase-change of phase-change fracturing fluid to form stable support. According to the temperature distribution in the cracks

the fracturing fluid system with different phase change temperature can be selected to achieve the purpose of"phase transition in a short time and with effective support". The research result helps to improve the pertinence of self-generated solid chemical fracturing working fluid system and operation technology design.