Oil firm Cairn Energy has got cracking on its West Greenland offshore drilling campaign, with drilling commenced on two wells.The AT-7 well in the Atammik Block, some 160 kilometres offshore of Nuuk, west Greenland, and the LF-7 well in the Lady Franklin Block, about 300 kilometres offshore of Nuuk, have both started operating.The company said the Leiv Eiriksson, a fifth generation semi-submersible ocean rig, and the Ocean Rig Corcovado, a sixth generation drill ship, are to carry out the drilling programme off the coast of Greenland this summer. The AT-7 prospect in the Atammik Block and LF-7 prospect in the Lady Franklin Block are in water depths of 905 and 989 metres respectively. --jh