Slickwater fracturing has been widely utilized in the exploitation of shale gas reservoirs around the world. Due to the difficulty of migrating proppant deep into the reservoir, a large number of fractures with little or no proppant placement would form after the treatment, acting as main flow paths for gas production. And the sharp production rate decline after a period of production is considered as the result of closure of this kind of fractures. First a summary of the research on the deformation of natural fractures and shale creep behavior is given. Then a simplified numerical non-propped fracture model is established to simulate the fracture closure under normal stress, which consists of the elastic deformation caused by pressure drop in fractures and the deformation caused by formation creep behavior. The results of the simulation show that, the fracture closure caused by creep is too large to be ignored. The fracture deformation under the conditions of different normal stress and surface contact area is also studied in the paper.

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