Shale reservoirs have developed micro and nanoscale pores, characterized by low porosity and low permeability. After hydraulic fracturing, the reservoir exhibits a multi-scale pore-fracture structure consisting of matrix, natural fractures, and hydraulic fractures. The process and mechanism of fluid flow are complex. In this paper, the variation range of reservoir permeability and crude oil viscosity in different regions of the Sichuan Basin is summarized. A seepage model for hydraulic fracturing of shale oil is established considering two scenarios: matrix type and naturally fractured type. The model can be used to simulate the reservoir pressure distribution and spreading range under different conditions. The results indicate that the spreading range of shale oil gradually increases with the continuous exploitation, but the increase amplitude gradually decreases. When the reservoir permeability is higher, the oil viscosity is lower, and the density of natural fractures is higher, the rate and the range of spreading will be larger. For matrix type reservoirs, the region between two adjacent fractures with a cluster space of 10 m can be fully utilized after 5 months, and the maximum spreading range for a single fracture is between 36 and 43 m after several years. For naturally fractured type reservoirs, due to the seepage channels provided by natural fractures, the region can be fully utilized after only 4 months keeping other parameters the same, and the maximum spreading range for a single fracture reaches 45–52 m. This model can be used to guide the optimization of horizontal well fracturing parameters, which is beneficial to effectively develop the unconventional reservoirs, and improve the oil production by fracturing operation.