The company said this figure was determined from an interim assessment of the area, based on drilling results and the re-interpretation of two seismic surveys, of which one was also reprocessed.

The NE2 accumulation is located updip of two earlier wells – Puffin-3, drilled in 1975 and which recovered 40-42 degree API oil but was not flow-tested, and Puffin-4, drilled by BHP in 1988 and recovered a wireline sample with a trace of oil.

“It is essentially an extension of the Late Cretaceous Puffin … Formation, containing Puffin-5 and Puffin-7,” AED said.

“The two areas are separated by a faulted zone and saddle, and as such show different oil-water contacts.”

In addition, AED said that unlike the very flat, “table-top” Puffin-5 structure, seismic shows the updip Puffin-3 structure to be a more anticlinal feature with a larger oil column of up to 43m.

Of the OIIP figure, AED estimates 40-70% would be recoverable.

“This result indicates the attractiveness of the NE2 area, particularly with regard to its close proximity to the production facilities.”

AED plans to initially drill one exploration well on this structure as part of the proposed three-well program planned for the Puffin field later this year, following which a reserve statement for NE2 will be prepared and independently reviewed.

The company said that any reserves attributable to Puffin NE2 would be in addition to the previously announced northeast main field (NE1) P50 recoverable reserve figure of 40 million barrels.

The Puffin-8 development well, in the NE1 area, is due to spud on either Friday or Saturday this week.