Tree Gate Valve Isolation – Mac Pac

The Client

A major oil and gas operator in the UK approached KCI Ltd to provide isolation solutions for Christmas tree valves on a water injection well. The client faced the failure of all three inline gate valves and required a reliable intervention to proceed with well abandonment and intervention operations.

The Results

KCI’s operation was a complete success. The safe, effective, and efficient isolation of the well eliminated the need for a time-consuming and costly well kill or freeze operation. This rigless isolation method saved significant costs and ensured the well could be safely closed until planned intervention work commenced. The client expressed high satisfaction with the outcome.

The Challenge

The client needed to isolate leaking Christmas tree valves to break containment and enable the installation of a secondary swab valve. This was crucial for well intervention and abandonment operations to proceed. Key challenges included:

  • All three inline gate valves exhibited significant failure, with a recorded leak rate of 10 litres per minute and a pressure build-up (PBU) of 540 psi.

  • Previous attempts to seal the valves using Clare 601 and 701 grease proved ineffective, as leaks persisted at the same rate.

The Solution

KCI implemented a methodical, engineered approach to address the issue:

Swab Valve Isolation - Deployment tooling was connected to the SWAB valve, and 1.5 litres of Mac-Pac were injected. A PBU test was conducted, and the valve functioned and tested with zero leaks or PBU recorded.

Lower Master Valve (LMV) Isolation - Deployment tooling was connected to the LMV, and 5.5 litres of Mac-Pac were injected. A PBU test was conducted, followed by valve functionality and testing. While no PBU was observed, a minor fluid leak was detected at the vent point. An extended overnight PBU test confirmed successful isolation with minimal fluid leakage.

Upper Master Valve (HMV) Challenges—The HMV's actuator spring was found to be broken, preventing valve functionality. Despite this, the well was safely shut in pending planned intervention work.

Testimonial

“KCI have always provided personable, professional, and value-adding service in both surface and subsea wellhead issues. They don’t just provide a product; they complete the required engineering on each job to ensure the highest chance of success. KCI are interested in helping where they can but will also clearly outline any limitations when planning a job. If you have a leak, we highly recommend giving them a call.”