Abstract Developed fractures are important storage space and permeable channel in hydrocarbon reservoirs. However, they will lead to drill-in fluid loss and induce severe formation damage. Fracture plugging with granular… Click to show full abstract
Abstract Developed fractures are important storage space and permeable channel in hydrocarbon reservoirs. However, they will lead to drill-in fluid loss and induce severe formation damage. Fracture plugging with granular lost circulation material (LCM) is most commonly used to control drill-in fluid loss. To our best knowledge, traditional research about LCM bridging mainly performed by the trial-and-error method. However, the behavior of granular LCM migration and bridging in a fracture on mesoscale is still unclear. In this paper, the coupled CFD-DEM approach is used to simulate the flow of granular LCM in a vertical fracture. The effects of particle size distribution (PSD) and concentration on the fracture plugging process are studied by a series of controlled numerical experiments. The research suggests that: (1) When Wf/D50<1.5, the critical particle concentration softly increases with particle size distribution (PSD), but the area with Wf/D50>1.5 the critical particle concentration sharply increases with PSD. (2) The plugging process can be divided into two distinct stages from pressure drop rate: particle bridging and particle accumulation. (3) The drill-in fluid loss rate is affected by the plugging process, the structure of plugging zone and PSD.
               
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