1. n. [Perforating, Well Completions]

The area surrounding the wellbore that has been harmed by the drilling process, generally as a result of mud or cement-filtrate invasion. Near-wellbore damage can significantly affect productivity and is typically easier to prevent than it is to cure. Although almost always present, a lightly damaged zone around the wellbore can be bypassed by perforation tunnels to create connecting conduits from the wellbore to the undamaged reservoir formation. More severe cases of damage may require a matrix-acidizing treatment to restore the natural permeability, or a hydraulic fracturing treatment to create a new high-conductivity flow path to the reservoir.

See related terms: hydraulic fracturing,  matrix acidizing