Poland-focused San Leon Energy has uncovered rock formations at a Polish exploration well that are akin to the bounteous Bakken Formation in North America. A successful stimulation test on the Czaslaw-1 well in the Nowa Sol licence in Poland indicated that the rock formation would yield hydrocarbons from 'fracking' drill techniques. Aim-listed San Leon's Executive Chairman Oisin Fanning said: "Results of these tests have been as good as we could have expected and go a long way to building what could be regarded as a Bakken-type resource play."There is a huge amount of oil in place in the Main Dolomite and we are committed to unlocking both the conventional and unconventional potential of the petroleum system." During a four-day stimulation test, small amounts of hydrocarbon gas were produced and flared along with burnt acid and small amounts of oil. The company said that analysis of the downhole pressure measurements showed "satisfactory" reservoir pressure of 129 bar, with "pressure transient analysis indicating encouraging system permeability of 0.01-0.1 measured depth, which is in line with that of the Bakken Formation in North America". Fanning said: "Successful further stimulation of this well, and the drilling and stimulation of a number of appraisal wells, would be required to establish this as a developable resource, but any such success would have a material positive impact upon both San Leon and Poland."San Leon's Polish team are now working on a plan for the well with US stimulation experts, any further operations expected this summer, subject to permissions and equipment availability. Shares in San Leon Energy were up 2.1% to 7.3p at 11:45 on Thursday. OH