Particle plugging:
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.

Damage:
General term to describe the reduction in permeability to the near-wellbore area of a reservoir formation. There are several recognized damage mechanisms, such as the invasion of incompatible fluids swelling the formation clays, or fine solids from dirty fluids plugging the formation matrix. Because formation damage can significantly affect the productivity of any well, adequate precautions should be exercised to avoid damage during all phases in the life of a well.