Chevron confirms Britannia tieback for Alder in North Sea
Britain’s government has approved Chevron’s plan to develop the high-pressure/high-temperature Alder field in the UK central North Sea.
The project calls for a design capacity of 110 MMcf/d of natural gas and 14,000 b/d of condensate. Chevron expects first production in 2016.
“Our decision to proceed with this valuable asset was enabled by the right combination of technology, commercial conditions, and knowledge sharing on high-pressure/high-temperature experience,” said Craig May, managing director of Chevron Upstream Europe.
Another factor was the government’s enhancedSmall Field Allowance of 2012, designed to support development of small fields in a mature oil and gas basin.
Alder is in block 15/29a, in a water depth of 150 m (492 ft), 60 km (37 mi) from the UK/Norway median line. The field will be developed via a single subsea well tied back 28 km (17 mi) to the Britannia platform in block 16/26.
The semisubmersibleBlackford Dolphin, contracted to Chevron from mid-2015 for a multi-well program, will drill the well.
Produced fluids will be processed at a new dedicated module to be installed on the Britannia Bridge Linked Platform (BLP), which is to be constructed by ConocoPhillips acting as substitute operator on behalf of Britannia Operator Ltd. Gas will be exported to the Scottish Area Gas Evacuation (SAGE) terminal at St Fergus.
Technologies to be deployed for the development include Chevron’s first high-temperature/high-pressure vertical monobore tree, vacuum insulated tubing, a reeled 10-in./16-in. pipe-in-pipe system, and ahigh integrity pressure protection system.
About 75% of the development work will be handled by UK vendors. Main contracts are:
- Technip will provide 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 flowline, umbilical and tie-in spools. This work will be performed in Aberdeen, Evanton, and Newcastle.
- OneSubsea in Leeds will design, manufacture, and supply two HP/HT vertical subsea monobore trees and wellheads.
- Aker Solutions in Aberdeen will design, manufacture, and supply the subsea control system, including the hydraulic and electrical components to be installed both subsea and on the BLP.
Chevron North Sea Ltd. operates the project with a 73.684% interest; co-venturer ConocoPhillips (UK) has a 26.316% interest.