The estimate was reached after operator Unigeo remapped and re-evaluated the Ja-11 prospect and completed reprocessing of seismic.

The results are extremely encouraging, Carpathian said.

Drilling tenders have been issued, closing at the end of the month, and spudding of the Ja11 well is expected to start late August, taking 14 days.

The well is located about 1.5 kilometres north-west of the 2004 Ja-3a gas discovery.

The operator has also said the base gas price received by local producers has reached US$5.20 per thousand cubic feet with potential for increases during the northern hemisphere winter.

Carpathian said the rise in potential reserves following the study, together with the gas price, suggest its 60% interest in the well could provide significant returns in the event of a discovery.

The company also said its Krasna-7 and 8 wells started production in early May, following their winter shutdown, and are producing about 60 barrels of oil per day.

Carpathian has a 75% interest in the Krasna field, also in the republic, before payout, and a 50% interest afterwards.