Leaky casing hanger created potential requirement for a sidetrack
An operator offshore Qatar had been forced to shut in a well featuring a gas lift completion because of high pressure in the 9 5/8-in × 13 3/8-in annulus. A leak was suspected in the 9 5/8-in casing, somewhere between 3,000 ft and 5,000 ft, but an ultrasonic imager log eliminated that possibility, showing only minor corrosion at about 500 ft.
Subsequent testing identified a leaking seal on the 9 5/8-in casing hanger in the wellhead. With the casing integrity compromised, the conventional solution would be to sidetrack, run a new 9 5/8-in string, and install a new seal—an expense the operator wanted to avoid. Instead, it was recommended to only replace the failed seal. This required cutting the 9 5/8-in casing at a depth above the top of cement and pulling out the cut section together with the casing hanger. Any remedial solution had to be rated gas tight for the planned 2,000-psi [140-bar] injection pressure and robust enough to last for the life of the well.
Casing Reconnect system restored integrity of cut casing
Casing Reconnect metal-to-metal, gas-tight casing repair system is an ISO 14310 V0–rated, full-axial-load-bearing reconnection solution that uses proprietary Metalmorphology metal-to- metal sealing and anchoring technology. The operator selected the 9 5/8-in repair system because it delivers a connection with
no moving parts
- metal-to-metal seals
- gas-tight specification
- no reduction in casing ID
- high load capability in both tension and compression
- 5,269-psi [363-bar] internal pressure rating
- 3,803-psi [262-bar] external pressure rating.