Sheffield castings and forgings for MonArb North Sea project

World leading expertise from Sheffield Forgemasters’ specialist offshore technology and project management division, will play a critical role in the construction of a new oil platform in the North Sea.

Offshore Group Newcastle (OGN) secured a £50m deal for the design and fabrication of an oil and gas ‘jacket’ – a huge, steel, offshore platform support structure which is fixed to the sea-bed – for operator Talisman Sinopec Energy UK’s MonArb project.

OGN awarded Sheffield Forgemasters a multimillion pound contract to design and manufacture the jacket castings – two pad eyes weighing 27 tonnes each and two 55-tonne trunnion nodes.

The pad eyes and nodes will form high strength and fatigue resistant joints to connect the main leg and brace tubulars which make up the jacket structure. These components will allow the massive 5,400 tonne jacket to be lifted, rotated and installed on the sea-bed at its location in the Montrose/Arbroath field - 130 miles east of Aberdeen.The jacket structure will support a 10,000 tonne deck.

Under a separate contract, awarded directly by Talisman Sinopec Energy UK, Sheffield Forgemasters has designed and manufactured four deck lift points – two castings of 35 tonnes and two of 38 tonnes plus four forged pins and four cast sheaths for lifting and installing the deck on top of the jacket. The contract was awarded following a competitive tendering process.

Paul Mockford, design director of Sheffield Forgemasters SFM, said: “We are the world experts in cast nodes. No other company in the world has our experience and knowledge of designing and manufacturing these complex safety-critical castings.

“Reliability and quality is critical in these situations and it is our unique track which means clients come to us for these components. These castings form an integral part of the structure and will need to function for the life of the structure in extremely harsh operating conditions.

“The castings for this project are critical to the installation and in-service structural integrity of both the jacket and the deck.”

As part of the deck contract Sheffield Forgemasters will also supply a 10-tonne steel joint for the flare boom on the platform. The flare boom is a steel projection off the side of the platform which supports the flare burner for safely flaring off excess gas.

The new platform will be bridge-linked to the operator’s existing Montrose platform which processes well fluids from the same named field plus the nearby Arbroath wellhead platform and subsea satellites.

The MonArb hub is expected to be able to handle 150 million cubic feet per day of gas and 30,000 barrels per day of oil.

The MonArb project is a £1.6 billion investment by Talisman Sinopec Energy UK Limited and its partner, Marubeni Oil & Gas (U.K.) Limited, to extend the life of the oilfields to 2030.The jacket, nearly 120 metres long, will be ready in spring 2014 with installation expected in summer that year.

Sheffield Forgemasters worked with OGN on the the supply of cast steel pad-eyes for the recent Apache oil platform in the Forties oilfield, the largest oil field in the North Sea. This jacket was completed and installed in the summer of 2012.

Sheffield Forgemasters was recently awarded Energy Industry Company of the Year at the 2013 Insider Yorkshire International Trade Awards.