A type of damage in which foreign particles injected during normal well operations, such as drilling, completion, workover, stimulation or enhanced recovery, block the near-wellbore formation, reducing well productivity.

Potentially damaging particles in drilling fluids include clays, cuttings, weighting agents and fluid-loss control materials. In workover and stimulation fluids, suspended solids include bacteria and polymer residues. Foreign plugging particles can also be introduced as a result of poor water-handling practices. These foreign particles include debris from tanks and tubing.