Abstract:Since the permeability of gas shale is extremely low, hydraulic fracturing is the main measure to obtain an economic shale gas productivity. Shale reservoirs have long production cycles and artificial fracture conductivity is extremely sensitive to the fracture deformation. A large number of narrow self-supporting fractures play an important role in the gas desorption and flow. Shale reservoir has a certain creep characteristic, its creep rate increases with the clay content. After fracturing, the reservoir generates a large number of cracks and crack-closure creep is the main part. Fracturing treatment greatly increases the reservoir creep rate and the impacts of creep on the fracture conductivity cannot be ignored. The fracture closure creep rate is related to the interactions between fracture interfaces and proppant. It is also proportional to the matrix creep rate. Complex fracture network and tiny fractures have larger creep rate and greater effects on flow conductivity. Therefore, the creep deformation of fractures should be taken into account in shale gas numerical simulation. And, in-situ stress calculation and proppant selection should also consider the effect of creep. Maintaining fluid pressure is helpful to enhance fracture conductivity and improve gas well productivity and recovery.