South Wales Gas Pipeline, United Kingdom

As the North Sea reserves around the UK are being depleted the country must look for alternative sources of gas to supply both households and industry. The new supply sources are coming from Russia, Norway and also pipelines from Europe. But one of the major sources of gas (over 23% by 2012) for the UK is set to be the new South Hook and Dragon LNG terminals in Milford Haven, West Wales.

These gas projects are now nearing completion and will provide gas from the Middle East via LNG tankers to the gas grid. One of the problems with this was that the pipelines connecting this area of Wales with the nationwide UK gas grid were not large enough.

Consequently a major pipeline construction project has been undertaken to provide a new 48in (1,220mm) high-pressure gas pipeline from Milford Haven in Pembrokeshire to Tirley in Gloucestershire (national gas network), a distance of 197 miles (316km).

The pipeline cost has been estimated at around €700m and will be completed during 2008.

GAS PIPELINE CONTROVERSY

The construction of the South Wales gas pipeline has stirred up a great deal of protest from climate activists and environmental campaigners during construction. Part of the route (16-mile section) passes through the Brecon Beacons National Park and although the park authority objected it went ahead (National Grid has taken expert advice and are restoring the affected parts as the pipeline is 1.2m underground).

Campaigners have raised concerns about the safety of the pipeline as it is one of the first such high-pressure installations in the UK. In addition some sections have passed through seismically active areas of South Wales, such as Trebanos, and this has concerned local residents worried about leakage.

Finally the safety of the LNG installations at Milford Haven have been called into question from the point of view of collisions between tankers as it is such a busy port and also because it is a potential target for terrorist attack.

There have been many protests against the pipeline and planning decisions have been hurried through their due process at many local councils along the route of the pipeline. However the pipeline has been rule to be 'a critical part of the future energy needs' of the UK by the DTI.

SOUTH WALES PIPELINE ROUTE

Planning for the pipeline started in 2003 (route was decided in January 2004 to March 2005) and the land-based pipeline was decided on as the best option as a subsea alternative was considered as too expensive (land acquisition occurred between March 2005 and April 2006). The pipeline has a much higher operating pressure than has normally been seen in the UK. The pressure is 94bar(g) (1,364psi) as opposed to 85bar(g) (1,231psi).

The pipeline originates at Herbrandston from the South Hook LNG facility (Qatar Petroleum and ExxonMobil will operate it – it is one of the biggest in the world) the pipeline then picks up the smaller Dragon LNG terminal at Waterston and proceeds to Milford Haven and then onto Aberdulais in the Neath Valley (75 miles, 120km).

At Aberdulais the Cilfrew pressure-reduction station reduces the pressure of the gas and turns flow into the South Wales gas grid – this section (phase I) was completed in April 2007 (DTI consent granted in December 2005).

The contractor for the Milford Haven – Aberdulais section was Nacap Land & Marine joint venture. The pipeline continues onto Felindre where there is a compressor station to repressurise the gas.

From there the pipeline runs to a further pressure-reduction station in Tirley near Gloucestershire, before joining the UK grid for the remainder of the country.

The Felindre to Tirley section marks phase II and began construction in February 2007 (DTI consent granted in February 2007). The contractors for phase II include Nacap Land & Marine joint venture (Felindre to Brecon) and Murphy Pipelines Ltd for the Brecon to Tirley section.

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