A two-dimensional network model to simulate permeability decrease under hydrodynamic effect of particle release and capture

A model was developed to simulate permeability decrease induced by hydrodyn amic effects when injecting a fluid in a reservoir with respect to particle release and capture mechanisms and the parameters of the fluid-rock system . The kinetics of particle release and capture were integrated after comput ing the initial permeability of the porous medium with a square lattice of a two-dimensional network model. The rate of particle release is related to the difference between a microscopic velocity of the fluid and a critical velocity. The permeability decrease shows a direct link to the reduction of pore throat radii by three mechanisms of particle capture: straining and p article accumulation through direct interception or diffusion. Comparison b etween the simulations and the experimental results shows that the model re produces the physics of the permeability decrease phenomenon, although the values are overestimated. The difference between the two sets of results ca n be explained by the fact that the simulations are realized at constant pr essure whereas the experiments are realized at constant flow rate, and that re-entrainment of the trapped particles was not taken into account in the model.