US Patent 7520335 Cased hole perforating alternative

Casing is scored but not penetrated in one embodiment of a method that allows access to the formation without perforating or section milling the casing. In the run in condition the casing is impervious, to allow cement to be pumped through it to seal the annular space between the casing and the wellbore. After the cement is delivered and displaced through a shoe, the casing is expanded in the regions where it was scored to create openings that go against the wellbore wall. In between the expanded sections the cemented casing offers isolation between adjacent formations.