US oil & gas producer Nostra Terra reported good drilling results from a well in Oklahoma but said another one fell short of hopes, hitting its shares.Nostra said production rates from its CT15 well topped management's expectations. The group owns an 11.62% stake in the well, the third largest in its Chisholm Trail portfolio.But Nostra said initial production from its CT11 well, in which it has a 3.55% interest, failed to match management's expectations after it found a blockage, which may need cleaning out if it is to increase production from the well.Another well in which Nostra has a 20% stake, CT14, has been drilled and the group plans to announce its production rates when they have stabilised.Chief Executive Matt Lofgran said: "Production from CT15 and CT11 is expected to add another $45,000 a month to the company's income and we look forward to results from CT14."With the repeated success in this prospect, we will continue to participate in additional wells as proposals are made."Shares in Nostra fell 0.04p or 12.9% to 0.27p by 16:15 in London.PW