Liner
A liner (other than slotted liners) is a string of casing which does not extend all the way to the surface. Liners are installed to permit deeper drilling, to separate the productive zones from the other reservoir formations or for testing purposes. Usually cemented up to the top of the liner.
- Usually cemented over its entire length to ensure a seal with the previous casing string.
- It is important to ensure that the liner overlap has a good seal.
- In cases of suspected cement seal quality a mechanical seal (liner packer . . .