Two major West of Shetland development projects are gathering momentum, with Houston-based INTECSEA having secured the facilities engineering services contract for the first stage of Chevron-operated Rosebank/Lochnagar, while Doris has started front-end engineering for Total-operated Laggan/Tormore.
Together, the projects represent billions of pounds’ worth of investment spread over several years, though it is far from clear how much of the engineering/fabrication and equipment manufacturing will, in fact, go to British companies because of intense competition from the Far East, US and Norway, and therefore what the real jobs potential could be.
However, Shetland is guaranteed major benefit from Laggan/Tormore, and one or more of the main subsea contractors in Aberdeen will likely win major packages.
INTECSEA – a unit of WorleyParsons – was awarded its contract by Chevron Energy Technology Company and covers development of the Rosebank North/Lochnagar North oilfields on blocks 213/26 and 213/27.
The company’s work includes evaluation of field development options and covers detail such as floating production unit options (Chevron has particularly been considering a production/storage vessel, though a semi-submersible is possible), subsea infrastructure, risers, topsides/process, oil storage and export options.
INTECSEA will work its part of the project out of Houston, with topsides support provided by parent company WorleyParsons Upstream. The job is expected to take six months to complete.
“We are pleased to provide to Chevron the complete suite of expertise required for developing facilities in the challenging Atlantic Margin environment from a single company, from deepwater subsea through risers, floating systems, topsides, and export,” said Uri Nooteboom, senior vice-president and project sponsor, in a statement.
Meanwhile, evaluation of the Rosebank/Lochnagar reserves continues, with the super-drillship, Stena Carron, working on contract to Chevron. The company is operator of blocks 213/26 and 213/27, and of the Rosebank/Lochnagar wells, with 40% interest. StatoilHydro holds 30%, OMV 20% and DONG 10%.
Turning to Laggan/Tormore, the early work has also gone overseas as Doris Engineering is a French group, though its UK subsidiary, Offshore Design Engineering (ODE), is also engaged in the task.
Laggan/Tormore is a gas-condensate resource. The reservoirs lie beneath 600m of water and some 140km north-west of Shetland. According to Total, the project will involve “extensive operations to build a new onshore gas terminal plus subsea facilities and pipelines”.
The overall development concept consists of a long-distance tie-back of subsea wells connected to a new gas processing terminal at Sullom Voe on Shetland, with further export of the processed gas to the UK Frigg (FUKA) pipeline system in the North Sea.
Total says the subsea production system will consist of two identical six-slot template-manifolds, with up to eight development wells required to produce the expected reserves and an initial plateau production rate of 500million cu ft per day.
The commingled, multiphase fluid stream will be transported to shore via two 18in production flowlines. The subsea wells will be controlled via an electrohydraulic control umbilical with a separate smaller-diameter flowline injecting a continuous stream of methanol to inhibit the production of hydrates which can form at the low temperatures and high pressures experienced. The gas export route will comprise a 234km trunkline linking Shetland with the MCP01 junction into the existing Frigg-St Fergus pipeline. First gas is expected in 2013-14.
The Doris work covers conceptualisation of the overall development, along with detailed engineering of the subsea production facilities, including flowlines and umbilicals and the export pipeline, as well as the onshore plant and the export pipeline
Total operates blocks 206/1 (Laggan) and 205/5a (Tormore). The company holds a 50% stake in 206/1, together with DONG (20%), Eni (20%) and Chevron (10%). Total has 47.5% of 205/5a, with Eni (22.5%), DONG (20%) and Chevron (10%).