Breagh Gas Field, Southern North Sea, United Kingdom
The Breagh gas field lies in blocks 42/13a and 42/12a of the Southern North Sea, 65km north-east of the UK. The field lies at a water depth of 194ft.
RWE Dea operates the field with a 70% interest. Sterling Resources owns the remaining 30%. The field development is estimated at approximately £1bn. First gas is expected in the second quarter of 2012.
The Breagh field was discovered in July 1997 by discovery well 42/13-2. The well encountered a 121m gas column, demonstrating the presence of hydrocarbons.
BP had earlier drilled a well, 42/13-1, in 1968, which was declared commercially non-viable.
Breagh geology and reserves
The Breagh field reservoir is of the Lower Carboniferous age and contains sandstones of the Scremerston Formation. Gas is found in stacked fluvial channel sands in two discrete intervals.
The field is estimated to contain nearly 600bcf of recoverable gas reserves.
Using data from the 42/13-2 discovery well, appraisal well 42/13-3 was drilled in 2007. The appraisal well flowed at a rate of 17.6MMcf per day and thus established the presence of significant hydrocarbons.
Two additional appraisal wells were drilled by the Ensco 70 jack-up rig: one in August 2008 and the other in January 2009. In March 2011, RWE completed the drilling of the 42/13a-6 appraisal well.
The well was drilled to a depth of 8,624ft and will be used as a future production well.
The Breagh field is being developed in two phases. The first phase of development began in 2011. It involves exporting gas through an offshore pipeline connected from new Breach A normally unmanned installation (NUI) platform to Cotham Sands, Redcar. A 10km long onshore pipeline will carry the gas for further processing at Teesside Gas Processing plant.
In phase II of development, another NUI, Breagh Bravo, will be installed on the east end of the field. Additional wells will be drilled from the new platform and tied back to Breagh Alpha. Phase 2 is expected to receive FDP approval in early 2012.
Breagh Alpha platform
The Breagh A platform was installed in October 2011 at the west side of the field. Seven production wells will be drilled using a jack-up drill rig of a similar size to the Ensco 102.
The jacket of the platform is 85m tall, with the topsides weighing 1,400t. The jacket is supported by piles weighing 4,000t.
The platform features a 10t diesel crane, a helideck, 12 well slots, a gas production manifold and seven risers. It also features overnight accommodation for 12 people.
The subsea production systems for the Breagh field will include dry Christmas-trees, production piping including chokes and a production manifold. The produced gas and fluids will flow from the Christmas-trees through the flowlines to the manifold.
From the manifold, gas and fluids will pass through the export riser onto the onshore processing facility.
A 100km export pipeline was laid at the Breagh field to transport gas and liquids onshore. The 20in pipeline is made of carbon steel API, and is laid at Coatham Sands. A 3in-diameter mono ethylene glycol (MEG) pipeline will also be laid to provide hydrate and corrosion inhibition. A fibre optic control cable for communications and control purposes will be laid along with the MEG pipeline.
From Coatham Sands, a new 10km onshore pipeline will carry gas and liquids to the Teesside Gas Processing Plant at Seal Sands, Middlesbrough. The plant is owned by Teesside Gas and Liquids Processing. A 3in-diameter MEG pipeline and telemetry system will also be installed.
The pipeline installation is underway and will be completed in the second quarter of 2012.
PPGS carried out a MultiClient 2D GeoStreamer survey of the Breagh field. px Group was awarded the contract for construction and installation of the onshore 20in and 3in pipelines, and the fibre optic control cable.
In November 2010, RWE Dea awarded the engineering, installation and pre-commissioning contract for the offshore pipeline and fibre optic cable to Allseas.
The contract calls for detailed design engineering of the export line, MEG pipeline and fibre optic cable. Allseas will deploy its pipelay vessels, Lorelay and Tog Mor, to lay the main and near-shore segment of the pipeline.
Heerema Vlissingen delivered the Breagh A platform under an engineering, procurement and construction contract awarded in August 2010. The platform was constructed at Heerema's Vlissingen yard in the Netherlands.
In March 2011, AMEC was awarded a £32m contract by TGLP to modify and extend the gas processing plant for processing the gas and liquids from the field.