DeepOcean UK completed work on the Liwan 3-2 development offshore China. The project is part of the Liwan gas project, located 300km southeast of the Hong Kong, and includes the Liuhua 34-2 and Liuhua 29-1 fields.
All three fields share a subsea production system, subsea pipeline transportation, and onshore gas processing infrastructure.
DeepOcean commenced work on the project for COOEC Subsea in March 2012. Volantis and UT-1, a free-flying jet trencher, conducted trenching and survey operations over 160km of the 30in Liwan pipeline connecting the Liwan central platform in 200m water-depth to the shore at China National Offshore Oil Corp.'s Gaolan gas plant.
Prior to trenching, activities included construction works involving crossings along the pipeline route utilizing the WROVs and technicians onboard Volantis to deploy over 100 mattresses along the pipeline in preparation for the lay campaign. Trenching activities with the UT-1 and dedicated crew achieved burial depths along the route deploying the UT-1 jetting swords to 2.5m below the seabed for trenching of the large diameter pipeline.
Upon completion of trenching activities in August 2013 in the shallow water section of the project for COOEC Subsea, Volantis was immediately contracted by Saipem to perform subsea field development activities in the deep water section of the Liwan 3-1 field operating ROVs in excess of 1400m water depth. DeepOcean UK was responsible for various tasks infield working closely with clients to deliver safe and efficient subsea operations.
Volantis’ superior sea-keeping capability and innovative launch and recovery systems onboard allowed both contracts with COOEC and Saipem to operate continuously through the harsh monsoon seasons with minimal downtime operating under contract for a continuous period of over 875 days.
“It was a privilege to be part of such a momentous project in China,” says Tony Stokes, DeepOcean Asia Pacific director. “Working on both segments of China’s first deep-water field development displays the confidence our clients have in DeepOcean’s ability to deliver trenching solutions along with diver-less construction work scopes in the dynamic Asia Pacific Region”
Elsewhere, DeepOcean was chosen by Statoil to provide seabed survey services, covering the Norwegian Continental Shelf. DeepOcean will use the light construction and survey vessel Volstad Surveyor to carry out the contract, which is expected to begin in 2015.
Image from DeepOcean, Volstad Surveyor