The Dumbarton field is situated on Blocks 15/20a and 15/20b in the UK sector of the North Sea in 459 feet (140 meters) of water. Formerly named Donan, Dumbarton is located 140 miles (225 kilometers) northeast of Aberdeen, Scotland and is owned and operated by Maersk Oil North Sea Limited.

Dumbarton was discovered by well 15/20a-4 in 1987 and appraised by well 15/20a-6 in 1990. Production from these two wells commenced in 1992 and produced until 1997, totaling an output of 15.3 million barrels of oil. After failed attempts of replacing the production wells with new ones, the operator decided to cancel any further development enhancements and abandoned the field in 1998.

Field Development

Maersk Oil acquired Dumbarton in November 2005 with the idea to redevelop it, which the government sanctioned on March 19, 2006. The field will be developed in phases but in total, Dumbarton will consist of eight production wells and up to two produced water disposal wells on the field and the nearby Lochranza field.

In January 2006, Maersk commenced the first phase of the redevelopment project by drilling five horizontal producers and one deviated produced water injection well, and tying them back to the Global Producer III FPSO. Production commenced in the first quarter of 2007. On September 23, 2008, two additional production wells and one deviated-water-injection well were brought online, bringing the field's total production to 40,000 bopd.

The second phase of development calls for a second drilling center, located close to the first, consisting of a subsea manifold with up to three subsea producers clustered around it and a fourth remote producer tied-back by a 2 mile (4 kilometer), 8-inch-diameter flowline. Also, a third water injection well will be added to the development program, and all five of the wells will be tied-back to the Global Producer III FPSO. This phase of development commenced on October 2009.

At the end of December 2009, Lochranza, a satellite field, was tied into Dumbarton and came online. Further plans include drilling a second well in the early part of 2010.