Long & Short String Control Line Leak Repair + Tubing Hanger Isolation Product: IG-FP + MS-Sealant 02

The Client
Industry: Oil & Gas
Location: Confidential
Operator: Major North Sea Operator

The Results
The Long & Short String Control Line leaks were successfully repaired using KCI’s IG-FP Sealant, restoring the integrity of the hydraulic system. The repair was tested at 5000 psi with no pressure drop-off, ensuring no further A-Annulus pressure intrusion. Additionally, MS-Sealant 02 was deployed to the Tubing Hanger Void, preventing further communication with the A-Annulus and protecting the Environmental Gasket.

The successful repair allowed the high-producing well to be safely brought back online, maintaining the integrity of the Downhole Safety Valve (DHSV) system. The operator was highly satisfied with KCI’s effective and efficient solution.

The Challenge
During operations, the Long & Short String Control Lines were found to be in communication with the Tubing Hanger Void and A-Annulus, with an A-Annulus pressure of 78 psi recorded in both Control Lines and the Tubing Hanger Void. The objective was to repair the hydraulic leak in the Control Lines, prevent A-Annulus pressure from affecting the system, and restore the integrity of both the Control Lines and Tubing Hanger Void.

After the initial repair, the A-Annulus remained in communication with the Tubing Hanger Void through the Tubing Hanger Body Seal, requiring further intervention to reinstate system integrity fully.

The Solution
KCI provided an engineered solution utilising specialised sealants, bespoke tooling, and technical expertise. The repair process included the following:

  1. Control Line Leak Repair:

    • IG-FP Sealant was deployed into the Long & Short String Control Line Ports, followed by standard control fluid to repair hydraulic system leaks.

    • The system was pressurised to 5000 psi against the leaking connections, confirming successful isolation with no pressure drop-off.

    • Safety valves remained fully functional, and no A-Annulus pressure was detected when vented.

  2. Tubing Hanger Void Isolation:

    • MS-Sealant 02 was injected into the Tubing Hanger Void to prevent further communication with the A-Annulus.

    • 4 liters of MS-Sealant 02 were injected, locking in 1500 psi, ensuring no risk of sealant entering the Control Lines.

    • The repair eliminated further A-Annulus communication into the Tubing Hanger Void.

The Outcome

  • Successful repair and testing of the Long & Short String Control Line leaks.

  • The high-producing well was safely brought back online.

  • Downhole Safety Valve system integrity was fully regained.

  • No further pressure build-up within the Tubing Hanger Void.

  • The operator expressed high satisfaction with KCI’s solution.

Operator Feedback:
“Much appreciated and always great working with you.”
“Thanks and look forward to working with you guys next time. We have closed a good few threats using KCI products and services.”