Hannon Westwood’s analysis of drilling on the UKCS in 2010 shows that 67 exploration & appraisal wells were started during the year; 28 exploration spuds and five sidetracks, plus 20 appraisal spuds and 14 sidetracks.
Compared with 2009, exploration starts are 27% higher with six more wells, while appraisal starts are nearly 18% higher with three more wells.
These figures disguise a slight decrease of 6% in overall activity, accounting for four wells, when sidetracks are included.
Appraisal sidetracks were considerably lower than in 2009, at 14 compared with 28, though exploration sidetracks were almost par at five versus six.
Approaching half (45%) of activity occurred in the central North Sea (30 wells), with 16 wells in the southern North Sea (SNS), 13 in the northern North Sea (NNS) and four starts each in the west of Shetland and west of Britain (east Irish Sea basin) areas.
Seven E&A wells, all utilising mobile units, are currently active in the UK sector, two up on the level reported this time last year. On development & production drilling, 14 wells are active, utilising seven platform-based rigs and seven mobile units.
In the NNS, a single exploration well is active; Total’s 3/15a-14 on the Oban prospect, which spudded at the tail end of December, using the Sedco 714 semi.
To the west of Shetland, Chevron’s deepwater Lagavulin prospect well, 217/15-1, spudded on October 4 by the drill ship Stena Carron, has now been active for 120 days and has had to sidetrack.
Total has confirmed the Edradour prospect well, 206/4-2, to be a gas-condensate discovery. Drilled by the Sedco 714 semi, the well was suspended after an operation lasting 130 days. The rig is now in the NNS drilling the Oban well for Total.
In the CNS, four wells are ongoing. EnCore, with the Galaxy II jack-up, is drilling Catcher North appraisal well 28/9-3, the second of only two spuds to date in 2011. It follows success in the Eocene with the Varadero exploration well 28/9-2. Maersk’s Culzean HP/HT (high pressure/high temperature) appraisal sidetrack 22/25a-10Z continues with the Ensco 101 jack-up.
Also continuing from 2010 are BG’s Jackdaw appraisal 30/2a-8, with the Rowan Gorilla VI jack-up, and Talisman’s Josephine appraisal 30/13a-9, with the Ocean Princess semi.
The last-noted well was temporarily suspended in September and re-entered in late November.
One well is active in the SNS where, on January 3, RWE spudded 42/13a-6, the first UKCS well of 2011 and an appraisal of East Breagh ahead of field development. Centrica’s Pegasus prospect well, 43/13b-6Z, was abandoned in January after 34 days, and the jack-up Noble Julie Robertson moved to Great Yarmouth for major refurbishment work expected to last a number of weeks.
Carry-overs from 2010 amount to five wells, and the success rate for 2010, previously hovering at 40%, has already improved with a positive result from Varadero. The outcome of Centrica’s Pegasus remains under wraps for the time being, although 15 days at total depth should have been sufficient for testing.
It will be a few weeks yet before the full picture for 2010 can be revealed, but further positive outcomes are expected from ongoing wells.
The number of new well spuds demonstrates the re-emergence of a positive attitude to exploration in 2010. The forecast well pool remains healthy and is only minimally diminished by a spate of acreage relinquishments (including Wherry in the gas basin). And with the oil price breaking the $100 mark in recent days, the January blues might be behind us.
Simon Robertshaw’s column is courtesy of North Sea drilling analysts Hannon Westwood
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