Completion Equipment
Completion Equipment tests identification, function, and barrier classification of downhole and wellhead completion components. You must know which items can be used as barriers, how they are tested, and what limits apply.
Core equipment
- Retrievable and permanent packers isolate the annulus. A packer is a barrier only after it is set and tested.
- The SSSV is a fails-closed flapper valve, usually sited deep enough to be protected but shallow enough for wireline access. It is a secondary barrier, not the primary barrier.
- Landing nipples (no-go and selective) accept wireline plugs; the plug rating and nipple profile must match the expected differential.
- Gas lift valves, chemical injection mandrels, and sand screens are completion hardware but are not normally pressure barriers.
- The tubing hanger seals and supports the string; it must be tested after installation.
Worked example
The tubing above a packer must be recovered, and the packer is to remain as the deep barrier. A wireline plug is available for a no-go nipple just above the packer. The expected shut-in differential is 4,200 psi; the nipple is rated 5,000 psi and the plug 7,500 psi. The correct barrier is the tested plug in the nipple, with the well killed or a second barrier in place before the tubing is broken out. A gas lift valve or open nipple is not a barrier.
Traps
- Calling the SSSV the primary barrier.
- Pulling an SSSV without equalizing across the flapper.
- Using a plug whose rating is below the expected differential.
- Assuming a gas lift valve isolates the annulus.
- Forgetting that a nipple profile must match the plug.