CFD-DEM coupled simulation and regulation mechanism of micro-powder proppant migration behavior in complex fracture networks

Volume fracturing is a key technology for the development of low-permeability oil and gas reservoirs, and its effect depends on the migration and placement laws of proppants in fractures. Micro-powder proppants have attracted much attention due to their ability to effectively support complex fracture systems, but their migration mechanism still requires in-depth research. In this paper, a three-dimensional complex fracture model was established by using the CFD-DEM method to simulate the migration behavior of micro-powder proppants under key construction parameters, and the influences of proppant concentration, fracturing fluid viscosity and flow rate on their distribution were analyzed. The results show that an increase in particle size can accelerate sedimentation, but the growth of equilibrium height slows down. Increasing the viscosity of the fracturing fluid is conducive to long-distance transportation, but it will reduce the height of the sand embankment in the near-well area. Increasing the displacement can cause the proppant to migrate deep into the crack, forming a "long and flat" spreading pattern. The research results can provide a theoretical basis for optimizing the fracturing design of micro-powder proppants.