US focused oil explorer Nighthawk Energy said that drilling at its Taos 1-10 well at the Smoky Hill project in Colarado has confirmed an oil column, causing shares to surge on Tuesday morning.Taos 1-10 was drilled to a target depth of 8,315 feet and found 35 feet of gross pay interval in the Mississippian Spergen formation, thicker in size but similar to discoveries made at previous wells on Nighthawk's 100%-owned Arikaree Creek oilfield in the Denver-Julesburg Basin.Testing and completion is now underway and work is taking place to expand facilities to accommodate production, Nighthawk said.Meanwhile, the drilling rig has been retained to drill two further appraisal wells nearby. The company is targeting a "considerable" larger structure beyond the south-east fault of the oilfield."This phase of development of the Arikaree Creek oilfield has been very successful. We expect to have three wells producing from the field by mid June and can now follow up that success by establishing the extent of Arikaree Creek to the south," said Chairman Stephen Gutteridge. To finance the next stage of the Arikaree Creek development, the company has issued £3.8m of unsecured convertible loan notes."The objective of this relatively small-scale fund-raising is to deliver two more successful wells, which will not only further increase production and cash generation, but will enable us to establish material 1P and 2P reserves in the field, which would open up a wide range of options for the development of Arikaree Creek and further exploitation of our large acreage position."The stock was up 7.66% at 5.9p by 08:26 on Tuesday.