Shares in Mosman Oil & Gas more than doubled on Friday after the oil exploration and development company announced an oil discovery at the Petroleum Creek Project in New Zealand.The firm said testing on the Cross Roads-1 well has found "significant" moveable oil for a total potential pay of 17 metres.The Executive Chairman of Mosman, John Barr, said: "We are delighted to get an Oil Discovery in the first half of the first well, so soon after drilling commenced at Cross-Roads 1. "We are now encouraged by the oil shows in the Cobden limestone and look forward to seeing the results from drilling the rest of this well. The results to date appear to be a "proof of concept" for the 22 prospects and leads identified by geophysics at Petroleum Creek in addition to the Crestal area."The group has started detailed planning for the testing and appraisal programme, which will be carried out once the drilling has been completed to around 350-400 metres. The stock was up 241% at 40.45p by 14:43.NR