Chevron North Sea Ltd. has let several contracts totaling £550 million for subsea development work for its Alder and Rosebank deepwater projects offshore the UK.
Rosebank field, which lies 80 miles northwest of the Shetland Islands in 3,600 ft of water, is Chevron’s first deepwater development in the UK (OGJ Online, July 9, 2012). The field was discovered in 2004 and is estimated to hold 240 million boe of potentially recoverable resources, Chevron said.
Rosebank field will be developed using a floating production, storage, and offloading vessel, production and water injection wells, subsea facilities, and a gas export pipeline.
Alder field, meanwhile, was discovered in 1975 and lies 100 miles off Scotland and 37 miles from the UK-Norway median line. The high-pressure, high-temperature (HPHT) gas-condensate field lies in 492 ft of water and will be developed via a subsea tie-back to the existing Britannia Bridge Linked Platform (BLP) on Block 16/26.
Chevron let the subsea equipment vendor contract for the Rosebank project to OneSubsea UK Ltd. (formerly Cameron Ltd.). The contract includes the engineering, supply, and manufacturing of subsea manifolds, trees, and control systems. Equipment manufacturing will take place at various locations in the UK, including OneSubsea UK’s facility in Leeds.
Chevron also let three contracts for its Alder project. These were as follows:
• Technip was let a contract for detailed engineering, procurement, installation, and commissioning of the complete subsea system, including the main subsea manifold, subsea isolation valve manifold, 28-km of pipe-in-pipe flow line, umbilical, and tie-in spools. The work will be carried out in Aberdeen, Evanton, and Newcastle.
• OneSubsea UK was let a contract for design, manufacture, and supply of two HPHT vertical subsea monobore trees and wellheads. The work is for the firm’s Leeds facility.
• Aker Solutions was let a contract for design, manufacture, and supply of the subsea control system, including the hydraulic and electrical components to be installed both at subsea and on the BLP. Work is to be completed at Aker’s Aberdeen facility.
Rosebank field partners are operator Chevron 40%, Statoil (UK) Ltd. 30%, OMV (UK) Ltd. 20%, and DONG E&P (UK) Ltd. 10%. Chevron has a 70% interest in and is operator of Alder field.
Chevron will make a final investment decision on Alder field later this year and on Rosebank in 2014.