Liner Tie-Back String
A string of casing can be run at a later date after a liner has been installed and joined to it as long as the liner hanger assembly top (or weight set packer top, if it has been run) has been provided with a setting sleeve with tie-back extension (standard machined or PBR).
Reasons to run a tie-back string of casing include:
- damaged production casing due wear or corrosion
- upgrading of the production annulus to a higher working pressure, e . . .