Study on the influence of injection pressure variation caused by flow on hydraulic fracturing effect

In order to explore the change law of fracture pressure and crack propagation area of hydraulic fracturing specimens under different flow, the true triaxial hydraulic fracturing system was used to carry out physical simulation experiments of hydraulic fracturing under different flow. The experimental results show that the injection pressure variation is controlled by fracturing fluid flow, the flow is positively correlated with the change of injection pressure and fracture pressure; the pump pressure curve goes through four stages of liquid reserve, rise, fall and stability, the higher the flow, the shorter the reservoir time, the shorter the rise and fall period of the fracturing curve, and the higher the stable pressure; the crack propagation area increases with the increase of flow, and when the flow is 60 mL/min, the crack propagation area is the largest and the effect of the hydraulic fracturing is the best, but when the flow is more than 60 mL/min, the fracture network with single shape and small propagation area is likely to occur, and the hydraulic fracturing effect will be significantly reduced. The experimental results can provide reference for the parameters design of hydraulic fracturing technology.