EXPLORATION and appraisal drilling on the UKCS continues to show a marked recovery, with nine spuds reported during August alone – the Central North Sea currently leading the way.
To date this year, 39 wells, comprising 22 exploration and 17 appraisals, have spudded. That is an increase of 10 wells over the numbers reported in August’s Energy.
Three further sidetracks bring the grand tally to 12 – in total, 51 well starts to date.
Currently active are 14 E&A wells utilising mobile drilling rigs – eight semi-submersibles and six jack-ups.
Excluding sidetracks, and with the exception of 2008, this represents the highest level of exploration and appraisal well spuds to the end of August in the 13 years since 1997.
Production and development drilling is supported by 18 active wells, bringing the year’s total to 87 starts (48 spuds, 39 sidetracks and a single re-spud).
The Northern North Sea is back on the books with two E&A wells now drilling – Nautical’s 9/2b-4, an appraisal of the Kraken heavy-oil accumulation with the Ocean Nomad, and Sterling’s re-entry and successful sidetrack of the late-2008 Cladhan discovery, 210/29a-4, where a drill-stem test in the Upper Jurassic using the JW McLean was imminent at the time of writing.
West of Shetland sector, saw its first true spud of the year with Total’s 206/4-2 Edradour exploration well starting in mid-August with the Sedco 714. Hurricane’s Whirlwind exploration well, 205/21a-5, spudded little over a week later utilising the Borgsten Dolphin, having moved the short distance from Lancaster appraisal sidetrack, 205/21a-4, which was previously reported as successful.
Seven wells are active in the Central North Sea, Maersk’s Culzean HPHT appraisal, 22/25a-10, with the Ensco 101, being the only well in the CNS not to have started during August. Spuds are Maersk’s 15/19c-11 on the Dunvegan prospect with the Noble Ton van Langeveld; the GSF Arctic 4 on Nexen’s Polecat appraisal, 20/4a-9; Apache’s 22/7a-5 Aviat exploration well with the Galaxy II; BP’s Monan area exploration well, 22/20a-7, with the Paul B Lloyd Jr; BG’s Jackdaw appraisal, 30/2a-8, with the Rowan Gorilla VI, and Talisman’s Josephine appraisal with the Ocean Princess on 30/13a-9.
Expected imminently is Valiant’s exploration programme on the Viola North and South prospects on block 30/18b using the Ensco 100, which has come from drilling in the SNS for GDF Suez.
Wintershall’s Blakeney appraisal, 21/27b-7, was abandoned as an oil discovery after 15 days, the Ocean Nomad mobilising to the Kraken appraisal in the NNS; Apache’s twice sidetracked – for geological reasons – Phoenix appraisal 22/12a-12 was abandoned, probably as a success, after a total of 32 days prior to the Galaxy II mobilising to Aviat, and Talisman is understood to have suspended Halley appraisal 30/12b-10 after 41 days, the Ocean Princess mobilising to appraise Josephine.
In the Southern North Sea, three wells are currently active, but with no new spuds in August.
The Noble Julie Robertson remains on Centrica’s York pre-development well, 47/3a-15A; the Noble Byron Welliver continues operations for ATP’s on Kilmar appraisal 43/22a-3Z, and the Noble Scott Marks is active on Centrica’s 44/28a-6 Fulham prospect.
RWE’s Macanta exploration well, 42/14-2, with the Ensco 72, was declared dry after 49 days, the rig heading for port. E.On’s sidetrack of 42/28d-11 on the Tolmount Prospect using the GSF Labrador was reportedly suspended after 22 days, although the outcome is not yet publicised, but leaves the door open for re-entry. The rig also headed to port.
Hannon Westwood’s planned E&A pool stands at 166 wells, with indications that the Central North Sea will continue to see the lion’s share of drilling near-term, although the anticipated successful testing of Cladhan in the NNS will be the focus of much attention and will lead to further drilling in that region.
Simon Robertshaw’s column is courtesy of North Sea drilling analysts Hannon Westwood