EDINBURGH, UK – Cairn Energy has plugged and abandoned the last two wells of its 2011 exploration drilling campaign offshore Greenland.
The semisubmersible Leiv Eiriksson drilled the AT7-1 well in the Atammik block in the South Ungava area in 909 m (2,982 ft) of water, 202 km (125-mi) offshore Nuuk. The well had encountered a 113-m (371-ft) gross interval with 53 m (174 ft) of net reservoir quality Cretaceous sands, although the lithology of the highly permeable zone of losses remains unknown.
Cairn adds that severe mud losses and poor hole conditions hampered full evaluation of this interval which was thought to hold potential interest because of oil and gas shows. An MDT program recovered fluid samples to surface, but those examined on the rig revealed only mud filtrate and failed to establish hydrocarbons. However, Cairn has sent a set of sealed MDT samples to laboratories in the UK for further analysis, along with samples of gases recovered from gas influx events during operations.
Interpretation of MDT pressures indicates that the reservoir in AT-7 is water filled, but more analysis is needed to confirm the origin of the hydrocarbon shows.
The drillship Ocean Rig Corcovado has also completed the AT2-1 well in the same block, drilled in 1,045 m (3,428 ft) of water, 181 km (112 mi) offshore Nuuk and 46 km (28 mi) from AT7-1. It reached TD at 4,847 m (15,902 ft) in Cretaceous sediments, after encountering minor hydrocarbon shows.
Cairn commissioned a 1,500-sq km (579-sq mi) 3D seismic program on the Pitu block in Baffin Bay, and this is currently being processed with fully migrated results expected next year. Results of shallow borehole geo-chemical analysis confirmed micro seepages of oil and gas close to the main structures identified on previous 2D data. The 3D seismic acquired over parts of southern Greenland is also being processed, with fully migrated results are expected during the first half of 2012.
Cairn plans to review and assess its exploration campaign over the last two years, and is in farm- out discussions over certain areas for future operations.
It could acquire more 3D seismic survey over the Lady Franklin and Atammik region next year, and is also considering further drilling in the West Greenland basins.
Simon Thomson, CEO, said: “The first phase of Cairn’s exploration program in Greenland has encountered oil and gas shows across multiple basins and now reservoir-quality sands in the Atammik block. Whilst we have yet to make a commercial discovery we remain encouraged that all of the ingredients for success are in evidence.”