Offshore staff
EDINBURGH, UK -- Cairn Energy is preparing for its second exploration drilling campaign offshore Greenland following last year’s three wells.
The company plans to drill up to four further wells, recently winning approval from Greenland’s government on the locations of seven drill sites. This will ensure flexibility in program planning and provide options for appraisal wells in the event of a discovery, says Cairn.
At present, Cairn expects to drill one well in each of the Atammik and Lady Franklin blocks, west of the capital Nuuk, and one in each of the Napariaq and Eqqua blocks in the southern Baffin Bay west Disko area.
The campaign will test prospects with varying structural styles and play types, and will target potential gross resources of 3.2 Bboe at target subsurface depths between 2,500 and 4,750 m (8,202-15,584 ft).
In each case oil is the main target, although there is evidence of both oil and gas generation regionally. Cairn puts the chances of success in the range 10-20%, taking into account the frontier nature of the exploration and the lack of offset well data.
The wells will be drilled in water depths in the range 288-1,530 m (945-5,019 ft) using two drilling vessels, as in 2010. The total cost of the campaign is estimated at around $600 million.
The wells in the Lady Franklin and Atammik blocks will be drilled, respectively, on the LF-7 and AT-7 prospects.
Both contain multiple structural targets in the Tertiary and Cretaceous. The planned TD for AT-7 prospect well is 3,600 m (11,811 ft) and 4,500 m (14,764 ft) for LF-7.
There are follow-up prospects in both blocks with combined gross resources of more than 8 Bbbl or 14 Tcf.
Cairn was awarded the Napariaq block last December under the Baffin Bay bid round. Here the well will probe the Delta prospect, a large structural culmination in the Cretaceous where overlying Tertiary volcanics are expected to be thin or even absent.
The proposed drilling depth is 4,750 m (15,584 ft), and the well will target the potential Cretaceous reservoirs not reached in the Alpha-S1 well drilled last year. Alpha-S1 encountered oil shows in the thick (up to 1 km) Tertiary volcanic section.
Cairn’s Eqqua block, acquired under the Disko West license round in 2007, is south of the Sigguk block where the company focused its 2010 activities.
The Eqqua well will be on the Gamma prospect, a combination structural-stratigraphic trap in an interpreted Tertiary basin floor fan at 2,500 m (8,202 ft) overlying a deeper Mesozoic structural. There are potentially thicker reservoir sands 100 km (62 mi) from last year’s T-8 well, and at the same stratigraphic level as gas seen in T-8’s thin sands.
Cairn also plans to acquire two 1,500-sq km (579-sq mi) 3D seismic surveys over the Pitu block, in the north of Baffin Bay, and over southern Greenland blocks acquired in 2008. Both surveys will cover structural complexes where leads and prospects have been identified.
A third 3D seismic survey could follow, dependent on operational results.
05/24/2011
