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UK flag Engineering, construction and commissioning: Apache Forties, United Kingdom

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Project: Commissioning, engineering and construction services for Apache’s UK assets

Client/partner: Apache

Location: Apache’s UK North Sea assets

Value: US$160 million per annum


Start Date

Q3 2016

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Petrofac won the Apache onshore engineering and offshore construction contract in 2009 and began the transition to Petrofac of Apache’s five UK North Sea assets - the Forties Alpha, Bravo, Charlie, Delta and Echo.

When Petrofac commenced work on the Forties fields, Apache had already invested in excess of US$1.2 billion to renovate the mature and significant UKCS assets. Apache’s aim was to extend the expected life and increase production through continued investment in field-wide drilling activities and capital projects (both topside and subsea).  

In 2011, Petrofac was awarded the commissioning contract of the Forties Assets to add to the existing engineering and construction contract.  

In 2012, Petrofac signed a three-year contract to provide onshore engineering and both onshore and offshore construction services to all of the Apache North Sea assets. This included the Beryl Alpha and Bravo platforms in the northern North Sea and the Scottish Area Gas Evacuation (SAGE) gas processing plant at St Fergus, Aberdeenshire, UK. Petrofac's scope was extended to include topside brownfield and greenfield activity in addition to interfacing with subsea contractors.

We had some 340 employees working for Apache, 100 onshore based and 240 working offshore on rotation.

Key successes

  • Petrofac is well known for its experience in best in class minor modification services. We provided a minor modification services programme for Apache which included multidiscipline projects across all of the Forties’ existing systems
  • In 2011, we completed a £12 million debottlenecking project for the Forties Alpha and Forties Delta platforms to increase the deep gas lift flow levels, enhancing production rates. Much of the existing topsides equipment (vessels, gas scrubbers, production gas coolers, pumps and valves) were not sized to take increased amounts of gas, which caused flow bottlenecks that needed to be modified. The project was delivered safely, within budget and on schedule for Apache
  • One of our key capabilities is our successful shutdown delivery. We have a worldwide reputation for providing successful shutdown projects for our clients on time and within budget. In May 2011, we successfully delivered Apache’s biggest ever shutdown and turnaround (TAR), spanning over 22,000 man-hours over a two-week period

Apache's Bacchus tieback project

Petrofac played an integral part in the project delivery of Apache’s Bacchus Tieback project.

Bacchus was a high pressure/high temperature (HP/HT) field 6.8 km north east of Forties Alpha and was produced through three wells and tied back to the Alpha platform via a subsea pipeline bundle including production, produced water injection and heating, gas lift, chemical services, and power and control umbilicals.

This project involved many subcontractors and Petrofac’s scope involved the topside modifications on Alpha including:

  • Installation of the caisson riser
  • Location and installation of the primary equipment
  • Process tie-ins
  • Position and hook up of the subsea control equipment
  • Modifications to the safety, controls and electrical systems

Our services ranged from detailed engineering and design, procurement and fabrication management to offshore construction and commissioning. Design commenced in early 2010 and the project achieved first oil on 23 April 2012.