Nine mobile units are currently active on E&A drilling on the UKCS, with just a single platform-based appraisal ongoing in the Northern North Sea.
Overall, this represents a decrease of one unit in the sector since last month, Ocean Princess switching from appraisal duties to development drilling, albeit at the same location.
Well starts for 2009 number 18 exploration and 17 appraisal wells, a total of 35 wells – no change since our last update.
The number of sidetracks, however, has increased, with six wells having been plugged back for additional exploratory or appraisal legs, raising the number of sidetracks thus far in 2009 to 35.
Four wells are active in the Central North Sea.
Petro-Canada is in a second sidetrack of the Nutmeg exploration well, 12/25-4, utilising the JW Mclean, and remains the sole active exploration probe in the CNS.
Nexen’s Hobby North appraisal 20/1-11 has also been sidetracked in the last month, while Talisman initiated a second sidetrack, another appraisal leg, of the Jurassic Shaw discovery, 22/22a-7, utilising Ocean Nomad.
Following this September’s re-entry to drill a second appraisal sidetrack (9X) of Talisman’s June 2008 Burghley well 16/22-9Y, Ocean Princess subsequently kicked-off a development leg (6W) from the borehole, hence the “move” of a unit off E&A work for the time being.
Only Venture’s northern Acorn appraisal, well 29/8a-6, remains in its initial leg, at least for the present.
West of Shetland, three wells remain active, namely Hurricane’s Lancaster appraisal well 205/21a-4, nearing suspension after encountering light oil in fractured basement; DONG’s Glenlivet well 214/30a-2, where a second appraisal sidetrack (2Y) has been initiated following the Palaeocene discovery in the pilot hole, and OMV’s Tornado exploration well 204/13-1, which has also been sidetracked following the discovery of Palaeocene gas and oil.
The drillship, Stena Carron, is reportedly destined for Canadian waters once it completes operations on Tornado and prior to returning to the UK sector later in 2010 to continue its deepwater drilling programme.
Two wells remain active in the Northern North Sea.
Total-operated appraisal 3/9a-N52 is drilling in a mechanical sidetrack (52Z) from the Alwyn North platform, while the operator’s Balvenie exploration well 3/14d-18 is understood to have reached total depth. The Sedco 714 may stay in the province to drill the Laphroaig prospect in Total’s adjacent block 3/15 on completion of Balvenie operations.
Just one well is active in the Southern North Sea, where Venture initiated a second sidetrack (15Y) of the Annabel East appraisal infill well 48/10a-15.
On completion of this long-running probe, the rig, Noble Julie Robertson, could mobilise to drill the Alcyone prospect on block 53/3d, close to the south-east of Leman field in the Gas Basin.
E&A activity is temporarily on hold in the East Irish Sea, but the programme using the Ensco 92 is set to continue once the operations on BHP’s Lennox field well, 110/15-L14, now in sidetrack, are completed.
Six new sidetracks of ongoing E&A wells have compounded the effect of long-running drilling programmes on a currently limited pool of active rigs. Four of the mobile units currently operating are approaching or, in the case of Ocean Nomad, significantly beyond the three-month mark since initial spud.
The effect has been further compounded by the Ensco 92 on East Irish Sea development drilling since August 26, reducing the impact that these sometimes very short duration E&A wells in the Morecambe Bay area can have on statistics.
Such mitigating factors aside, it remains to be seen whether November and December make up for the stalling of new activity – well spuds – during October.
The current picture suggests that the lower end of our 10-20 wells estimate of new starts for the remainder of the year looks the more likely, although there is no shortage of well plans already rolling over into 2010.
Simon Robertshaw’s column is courtesy of drilling analysts Hannon Westwood LLP