Abstract:Consolidation plugging is an effective means to control drilling fluid leakage in oil and gas wells. Revealing the migration law of plugging slurry in wellbore-fracture and constructing continuous solidified body is one of the key problems to be solved in this technology. Therefore, the CFD numerical simulation method is adopted. A numerical model of vertical fracture consolidation plugging with dynamic change of wellbore pressure is established. The effects of density, plastic viscosity, yield stress, displacement and fracture opening of Bingham flow plugging slurry on the migration of plugging slurry were analyzed. The research shows that during the grouting process, the low-density plugging slurry preferentially enters the upper part of the vertical crack. The high-density plugging slurry preferentially enters the middle of the vertical fracture, and there is obvious mixing phenomenon. The plugging slurry migrates faster in the horizontal direction than in the vertical direction in the fracture. The plugging slurry with low viscosity is easier to enter the fracture. The higher the viscosity is, the longer the time for the plugging slurry to reach the same volume ratio at the fracture outlet is. The higher the volume ratio is, the lower the efficiency of plugging slurry replacing drilling fluid is. The effect of yield stress on the migration of plugging slurry in wellbore-fracture is not significant. The smaller the displacement or the larger the crack opening, the faster the instantaneous flow rate of the plugging slurry at the crack outlet increases, the larger the volume of the plugging slurry entering the deep part of the formation, and the smaller the volume of the plugging slurry required to reach the same volume ratio at the crack outlet. The results of numerical simulation have certain theoretical guiding significance for the formulation of curing plugging scheme.