Oil and gas exploration company Petroceltic said testing of an Algerian well had shown a large volume of gas in place.
The Dublin-headquartered company said its AT-2 well on the Ain Tsila field of the Isarene permit flowed gas at 4.9 million standard cubic feet a day, in line with expectations.
Petroceltic said it had filed a discovery declaration with Sonatrach for the well.
"Well AT-2 has successfully demonstrated that the Ain Tsila structure contains a large volume of gas in place, with pressure continuity demonstrated from AT-1 to AT-2," said chief executive Brian O'Cathain.
"It also demonstrated that the lower quality Ordovician sandstone encountered at AT-2, with porosities in the range of 5-10 per cent are capable of flowing gas at commercial rates, even in vertical wells.
"We are now working to integrate well and seismic data, with a view to optimising future development locations on areas of open fractures and/or higher permeability rock."