WHAT a difference a year makes. At the close of Q3 last year, 13 wells were active; just two more than current levels, but by then 41 exploration and appraisal wells (23 exploration and 18 appraisal) had been spudded.
Appraisal spuds to date in 2011 are 33% down on the same period in 2010, whilst more shocking is the exploration spud tally which shows a 57% decrease.
Even with a possible last-quarter run of activity, as anticipated approvals come through, with a conservative estimate of 10 more spuds due, 2011 is stacking up to be one of the quietest on the UKCS E&A front for more than a decade.
Indeed, if 1999 numbers are not bettered, not since 1971 – 40 years ago – will annual activity levels have been so low on the UKCS.
To the current scene.
The total number of mobile rigs drilling on the UKCS is now 20 with those on exploration and appraisal operations increasing from nine to 11 units over the last month. The five semi-submersibles, five jack-ups and solitary drillship active on E&A wells brings 2011 starts to 33 wells; 22 spuds and 11 sidetracks.
It has been necessary to re-start two wells and two have been re-entered for test programmes. Spuds account for 10 exploration wells and 12 appraisals although just one exploration sidetrack has been initiated compared with 10 appraisal legs.
Away from E&A duties, nine mobile rigs and seven platform rigs are involved in 20 development/production drilling operations including recent batch drilling on Huntington (Palaeocene) and Bacchus fields, bringing the year’s tally to 100 wells: 56 spuds and 44 sidetracks.
More than 40% of that activity is associated with just three fields; Forties and Alba in the Central North Sea and the Beryl area in the Northern North Sea.
West of Shetland, two mobile units are active on E&A operations; the Stena Carron drillship on Hess’s deepwater Cambo appraisal well 204/10a-4Z and Awilco’s semi-submersible WilPhoenix, which has re-entered to test Hurricane’s October 2010 Whirlwind discovery well 205/21a-5.
BP’s apparently successful Southwest Clair field appraisal, well 206/12a-3, was suspended in mid-August and the semi-submersible Byford Dolphin moved to the Don field to conduct abandonment operations.
Faroe Petroleum aban doned its Fulla discovery, well 206/5a-3, at the start of September, the WilPhoenix moving to Hurricane’s Whirlwind test, And Total, also on September 1, suspended the re-entered Edradour discovery, well 206/4-2, following what is understood to have been a successful DST (drill-stem test) programme on the gas condensate discovery.
The Sedco 714 semi-submersible then returned to its familiar patch in the Northern North Sea.
In the Northern North Sea, three rigs are active, an increase of two units since last reported.
Awilco’s WilHunter is preparing to suspend Nautical’s horizontal sidetrack, well 9/2b-5Z, ostensibly having satisfied its objective of establishing commercial flow rates from the Heimdal III (Palaeocene) sands ahead of development of the heavy-oil field.
The Sedco 714 spudded Total’s well 3/14a-19 on the Jurassic Ardbeg prospect on September 7 and EnQuest took semi-submersible Transocean John Shaw from Don SW completion operations to drill Ivy prospect, well 2/5-27, a near-field exploration probe close to the operator’s Broom and Heather fields.
Four units are active in the Central North Sea; semi-submersible Transocean Prospect on Nexen’s Polecat South appraisal, well 20/4a-10, and three jack-up units in the HP/HT (high pressure/ high temperature) province.
BG’s Jackdaw appraisal, well 30/2a-8, with the Gorilla VI was sidetracked for mechanical reasons early in September; GDF SUEZ continues operations on its Faraday prospect, well 30/1a-11, with the Galaxy II, whilst the Ensco 101 spudded the second of Maersk’s back-to-back Culzean appraisals, well 22/25a-11, in late August.
Low activity levels remain the norm in the Southern North Sea where two wells are currently drilling.
E.ON’s well 42/28d-12 on the Tolmount prospect grinds on, with the jack-up Ensco 92 nearing three months on location with no outward hint (at least) of mechanical problems delaying the operation. This is in contrast to the more recent spud, Perenco’s Leman South appraisal, well 53/2a-14, which recently required a re-spud two weeks after the initial start. The jack-up Energy Enhancer had previously been conducting well abandonments on the Welland field for the company.
Simon Robertshaw’s commentary is courtesy of North Sea drilling analysts Hannon Westwood
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