Crushed Zone
Once a well is landed across the zone of interest and the production casing / liner has been run, the well is perforated using guns loaded with shaped charges. The the firing of guns create perforation tunnels through the pipe and formation. The impact of shaped charges create a zone of reduced permeability around perforation tunnels, which is called the crushed zone. Crushed zone tends to reduce the flow of formation fluid into the well through peroration tunnels.