The group’s first deep well on the BNG area has detected oil and gas shows at a depth of 4,332 metres, it said.
Once clean-up work is complete, core samples will be taken to determine the size of the oil bearing column.
Roxi chairman Clive Carver said: "We are naturally delighted with these early indications and look forward to quantifying what has been discovered in the coming days and weeks."
The well has a planned total depth of 4,700 metres and the principle target was anticipated a depth of around 4,390 metres, in the middle Carboniferous formation.
On AIM, Roxi shares rose more than 80% in early deals to trade as high as 7.75p.
Roxi has a 58.41% stake in the BNG project.