Factors affecting particle retention in porous media

Particles can deposit in reservoir rocks or deep-bed filters and cause severe damage to their permeability. Several water injection wells experienced severe injectivity loss induced by the suspended particles in injected water. The mechanisms of permeability damage are attributed to adsorption, size exclusion and gravity settling of particles in porous media. Previous experimental studies show that particle concentration, fluid velocity, particle size and fluid ionic strength all have significant effects on permeability decline. The analysis on previous test data reveals that high particle concentration, low fluid velocity, and large particle size lead to more severe permeability reduction. Small particle size and high flow rate lead to deep but less severe permeability loss, and the damage tends to be shallower and more severe with increasing particle size and decreasing flow rate.