Study on the influence law of fracturing fluid viscosity and liquid injection rate on propagation behavior of hydraulic fractures in laminated shale

In order to study the influence law of fracturing fluid viscosity and liquid injection rate and other construction parameters on the hydraulic fracture propagation behavior in the process of hydraulic fracturing of laminated shale, firstly, the numerical simulation method is used to establish the relevant hydraulic fracture propagation model with the help of block discrete element method, and the simulation results are verified. Secondly, on the basis of the numerical model, the simulation study was carried out by setting different construction parameters. The study found that when the fracturing fluid viscosity and liquid injection rate are low, the pressure in the hydraulic fractures formed was low and evenly distributed, and the hydraulic fractures tend to spread along the bedding plane; when the fracturing fluid viscosity and liquid injection rate are high, the pressure in the fracture is high and the distribution difference is large. At this time, the hydraulic fracture tends to expand vertically through the bedding plane.