Woodside awards subsea installations for second NW Shelf trunkline

Nov. 8, 2002
Woodside Energy awarded a $55 million contract to Technip-Coflexip's and Subsea 7's Australian units to install part of the subsea installations for the second North West Shelf trunkline project.

By OGJ editors

HOUSTON, Nov. 8 -- Woodside Energy Ltd. has awarded a $55 million contract to a joint venture of Technip-Coflexip's and Subsea 7's Australian units—Technip-Coflexip Oceania and Subsea 7 (Australia) Pty. Ltd.—to install part of the subsea installations for the second North West Shelf trunkline project off Western Australia.

The contract is for subsea work associated with Woodside's new 142 km, 42-in. trunkline being constructed from Goodwyn and Rankin gas condensate fields on the North West Shelf to a point onshore near Karratha on the Burrup Peninsula, where an LNG plant also is being expanded (OGJ Online, Dec. 21, 2000).

The $800 million trunkline, currently being installed by a unit of Saipem SPA, will facilitate increased production from existing and potential fields in the area. The trunkline is scheduled to be completed and online in April 2004 to coincide with completion of a 4.2 million tonne/year fourth LNG train at the plant (OGJ Online, Feb. 7, 2002).

The scope of the contract includes tie-ins of the trunkline into existing infield facilities near the North Rankin A platform. Connections will be via hyperbarically welded and flanged spool pieces and a 350Te valve manifold. Pipeline work also includes dewatering and conditioning the trunkline and stabilizing it by installing about 900 concrete gravity anchors. Following start-up of the second trunkline, extensive pipeline system modifications will be carried out on the existing first trunkline at North Rankin A platform.

Engineering has begun, and Technip-Coflexip will utilize its CSO Venturer vessel to carry out subsea installations in three phases during August 2003-April 2004.