Multiple Tubingless Completion
Definition - What does Multiple Tubingless Completion mean?
Multiple Tubingless Completion is the completion in which two or more than two sources of supply are produced through an equal number of casing strings that are cemented in common wellbore. Every such casing has a smaller outside diameter with production from every common supply source being completely isolated by cement. Since the tubing diameter is small, its potential to re-enter or repair the well is limited. These are low cost completions used for short life and small fields.
Petropedia explains Multiple Tubingless Completion
In the process of Multiple Tubingless Completion, a subsea wellbore is drilled through a protective gas and oil formations. Two parallel casing strings with small diameters that are run into the wellbore are guided by the riser assembly. The casing strings have a common hanger at the upper ends. They are connected together at several levels with plurality of circulation and gas-lift crossover mandrels for the tool circulation. After that a Christmas tree is dropped on disconnectable pipe to the wellhead. This Christmas tree has two parallel casing strings with small diameter extending from lower end.
The upper casing strings have a common connector on lower ends for a connection with the hanger. A tension is applied to both sections of the casing strings with the help of tensioner located in the Christmas tree. The tensioner also spaces the upper section of the casing strings in the Christmas tree. Then a perforator gun is lowered in the landing nipple adjoining the formation. It is reciprocated till it rotates to a proper direction and avoids the perforation of other pipe strings in the wellbore and then it’s fired. The production of formation can be maintained by natural formation energy after every formation has been perforated. Many well servicing operations can be carried out by using pump-down techniques and tools.