The area surrounding the wellbore that has been harmed by the drilling process, generally as a result of mud or cement-filtrateinvasion. 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 reservoirformation. 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.

Related Terms:

matrix acidizing