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.