Conditions leading to plugging of perforations in wells and pore-throats in porous formations are investigated experimentally. Accurate correlations are developed for the effect of pore-throat-to-particle-size ratio on flowing fluid conditions and plugging time leading to particle bridging. It is demonstrated that the critical pore-throat-to-particle-size ratio vs. particle-volume- fraction Reynolds number can be correlated satisfactorily using an exponential function and the dimensionless plugging time vs. reciprocal-particle-volume-fraction yields an exponential-type correlation. Such empirical correlations can be used to determine and alleviate the conditions which induce perforation and pore plugging by migrating particles in petroleum reservoirs. These correlations reveal that the critical pore-to-particle diameter ratio below which plugging occurs may be greater than the unit physical limit.