In an annual reserves update, Gaffney Cline and Associates determined that 1P reserves were 34% higher at 853,000 barrels, while 2P reserves were down 50% to just over 7 million barrels.

Carnarvon said most of the 2P reserves related to the Wichian Buri field.

“The 2006 proven reserves saw a nominal increase,” it said.

“Probable reserves were negatively impacted by the structural complexity of the Wichian Buri and POE-6 fault blocks revealed on the newly acquired 3D seismic.”

As a result, some of these probable reserves were moved into the “possible” category, requiring further appraisal and development drilling before they could be moved back into the 1P and 2P classifications.

The estimates also included a small amount of 2P reserves for the Na Sanun East field surrounding the well bore of POE-9.

But Carnarvon said the figures were limited by the lack of well production history, core data and an undefined field oil-water contact.

“We consider that the methodology applied by Gaffney Cline for the 2006 reserve estimates is considerably stricter than that applied in previous years and we believe they are very conservative as commented on in their report,” Carnarvon chief executive Ted Jacobson said.

“The need for further drilling to appraise and develop the area is recognised and a very intensive drilling program of up to 37 wells has commenced, with the first well NS-3 currently being prepared for flow testing.

“Once several key wells are completed, the reserve estimates for our Thailand permits will be revisited later this year.”