Experimental study on the critical flow velocity for sand production in shale gas wells

The purpose of this study is to determine the critical flow velocity for the sand production of shale gas wells under different conditions through experiments and to predict the sand production of gas wells. The experiment is based on the API fracture diversion experimental device. To study the influence of shale physical properties on sand production, a shale rock plate was used as the propped material in the API fracture conductivity experiment. The results show that when the closure pressure exceeds the critical fracture point of shale, the critical flow velocity for sand production will decrease on a large scale. A proppant with a large particle size is helpful for maintaining fracture opening, and the critical sand production velocity is greater. The higher the viscosity of the fluid is, the lower the critical sand production velocity. This paper provides a reference method for determining the critical sand production velocity in shale gas wells.