Summary

To gain access to the leak from the vessel, the SCM was recovered via a dummy pod. A 500 m (10.000psig) 3/8” reel was then used to deploy the sealant through a hot-stab connection into the DHSV line in the wellhead through the HP1 port on the dummy point.

The leak rate was estimated in original diagnostic in excess of 10 liters/min at full system pressure at 500bar.

ROV video was run to the SEALMAKER hydraulic pump on the main deck to visually observe the leak repair operation subsea. The hot-stab was disconnected at the surface and loaded with SEALMAKER sealant and followed by hydraulic oil. The hot-stab was reconnected, leak tested, and then deployed to the seabed. After connecting the hot-stab into the Dummy HP1 Port, ROV was moved into position to monitor the leak visually. The reel was pressurized from the surface using the SMI hydraulic pump to 200 bar and the leak was visually confirmed with the ROV feed. Initial leak-off was 200-135bar/1min. Hydraulic oil was confirmed exiting the leak followed by the SEALMAKER chemical as the pressure fell below 120 bar. A complete seal was established at 118bar and all fluid leakage was eliminated. The seal was shut-in and allowed to cure for 1 hour with zero pressure loss and confirmed with zero leakage visually. The line was then cycled between 510-200 bar and then shut in at 510bar for 5 hours. The pressure /bleed cycling was repeated 3 hours later with zero leakage occurring. The dummy pod was pulled and minor modification were made to bleed the pressure subsea and then re-installed. A thorough flushing procedure was performed with 18 pressure/bleed cycles ran to ensure as much sealant was removed from the control line as possible. The dummy was then pulled and the SCM re-installed. The line was pressure tested at 458bar from the FPSO without leakage and well was then placed into service.