TSMarine’s Subsea Well Intervention Firsts

This is the first phase of a campaign by TSMarine which will include the installation and completion of up to 11 subsea trees in the Vincent field and a range of commissioning and decommissioning projects in region. The project marked a number of other milestones. This was the first time the deployment and installation on wire of subsea xmas tress from a monohull vessel has taken place in the region. Similarly, it was the first time a subsea well intervention project has been carried out using wireline services from a monohull vessel in Australian waters.
 
The intervention was completed in partnership with WellOps South East Asia and Schlumberger, both of which were integral to the success of the operation. The world record water depth for subsea wireline intervention from a monohull vessel is 377 metres. In TSMarine's first ever subsea well intervention project they operated at a water depth of 372m, a significant achievement within this successful project.

From the Havila Harmony, the trees were run using the vessels 150 tonne active heave compensated crane and a simple mechanical running tool. Locking and testing was supplied by the vessels ROV systems, which were fitted with a specially developed hydraulic power and tooling pack. Hanger and deep-set plugs were removed by slick line intervention using Wellops subsea lubricator (SID) and Schlumberger Wireline Services.

The Havila Harmony is on long-term charter to TSMarine and was delivered in March 2007. She is configured to undertake subsea decommissioning; rigless well intervention services, and subsea construction support activities and has a comprehensive safety case accepted by NOPSA, Australia’s National Offshore Petroleum Safety Authority, covering these and more activities. Built to the new and demanding “Clean Comfort V” Norwegian standards, the ship conforms to the highest level of environmental class conditions required of vessels of this type in the offshore industry sector.