Nine mobile rigs remain active on exploration and appraisal drilling on the UKCS – no change from the situation in late October.
Three are tied up on long-running wells – two heavy duty jack-ups in the central North Sea and a semi-sub west of Shetland – while weather conditions have continued to hamper a number of rig moves and operations.
A single “spud” and a sidetrack in November bring the year’s tally to 64 well starts (26 exploration spuds and four sidetracks, and 20 appraisal spuds plus 14 sidetracks). One suspended well was re-entered during the month to continue drilling operations.
The number of production and development wells, excluding workovers and other interventions, for the year to date has climbed to 114 (including 49 sidetracks) of which 21 are active, and utilising 11 platform-based derricks and 10 mobile units.
In the northern North Sea two rigs are active on E&A (exploration and appraisal) drilling. As Energy went to press, Xcite was preparing to production test the sidetrack leg of Bentley heavy oil appraisal 9/3b-6Z, with semi-submersible Ocean Nomad and EnQuest continuing operations on Don Southwest appraisal 211/18a-28 using the semi Transocean John Shaw.
West of Shetland, two exploration wells remain active. However, Chevron’s 217/15-1 well being drilled on the Lagavulin prospect by the drillship Stena Carron has been suffering weather-related problems. Total’s long-running Edradour prospect well 206/4-2 progresses with the semi Sedco 714 now more than 100 days into its programme and nearing TD (total depth).
Four wells are active in the central North Sea, the most recent start being Nexen’s 20/6a-7, a near-Buzzard appraisal on the Bluebell prospect using the semi Transocean Prospect. Prior to this, the rig had successfully delineated Nexen’s West Rochelle discovery with the 15/26b-10Z probe.
The operator also abandoned the Polecat appraisal 20/4a-9, drilled using the semi GSF Arctic IV after 91 days including a significant period at TD.
This is indicative of a discovery unless weather and/or technical difficulties also heavily impacted operations. The rig, has since transferred to a new owner, Awilco, and been renamed WilHunter. It has been moved to a shipyard in Gdansk, Poland for overhaul.
After 154 days of operations Maersk plugged the Culzean high pressure/high temperature appraisal 22/25a-10.
The jack-up Ensco 101 kicked off sidetrack 22/25a-10Z on November 20.
BG continues working on its Jackdaw appraisal 30/2a-8 and is 90 days into the task using the jack-up Rowan Gorilla VI. Meanwhile, the jack-up Ensco 100 moved off Valiant’s dry Viola North exploration well 30/18b-9 in mid-November to Dundee; while Talisman has re-entered, for a second time, its Josephine appraisal 30/13a-9 using the semi Ocean Princess, which had previously been on development drilling duties.
At the time of writing, the jack-up Galaxy II sits in port waiting on weather. It is scheduled to resume drilling operations in the Greater Catcher area (block 28/9).
No change is reported on rig numbers in the Southern Gas sector where Centrica’s 43/13b-6 is being drilled on the Pegasus prospect using the jack-up Noble Julie Robertson.
With a month to go before 2010 draws to a close, it appears factors beyond the industry’s control – namely weather – have put paid to the anticipated year-end flourish, but 2009 spud levels have already been bettered, and irrespective of final numbers, 2010 will have yielded a number of significant discoveries and progressed the appraisal of others.
Column courtesy of North Sea drilling analysts Hannon Westwood