Kazakhstan-focused oil & gas group Roxi Petroleum said the successful drilling announced last week on its flagship BNG project has unearthed more oil.The AIM-listed company said on 5 August that oil and gas shows at Well A5 were detected at a depth of 4,332 metres over the a 12-metres core range.On Monday, the company revealed that a further core of 18 metres was taken at a greater depth of 4,347 and 4,365 metres, meaning that the aggregate thickness of the gross oil-bearing interval is at least 33 metres.Chairman Clive Carver said he remains "excited by the potential of the deep horizons" at BNG.The company will now work towards a third core sample at depths between 4,365 and 4,383 metres."Once the depth of the oil bearing interval has been fully established the next step would be testing flow rates of the oil encountered," said analyst Brendan D'Souza from WH Ireland."We are highly encouraged by today's core sample results, which significantly increases the gross oil bearing region by nearly three times to 33 metres," he said.The stock was up 8.5% at 16p by 11:25 and now stands up nearly 43% over the last week.BC