The well penetrated the first of its three reservoir objectives, clipping the edge of a discrete oil accumulation in the Brinsley Abdy Formation, 250m above the field's main Westphalian gas reservoir.

This oil accumulation, was first identified in 1999 when Saltfleetby-3 encountered 12m of good quality net pay, however until now this oil accumulation had been regarded as being beyond seismic resolution and, therefore, it had not been appraised by subsequent wells.

It is estimated that the oil accumulation is stratigraphically entrapped over a 5km area with a gross vertical oil column of about 59m of which towards 14m represents net oil pay. The oil accumulation will now be considered for further appraisal and/or development.

Roc said it is too early to provide a detailed recoverable reserve but an order of magnitude indication is between two and three million barrels.

The oil accumulation is 100% owned and operated by ROC and will now join the company's three other pre-development projects in China, Mauritania and Australia, as a potential addition to the reserve base and source of future production revenue.

"The Saltfleetby-7 results have added a fourth potential development project to ROC's portfolio, placing the Brinsley Abdy oil accumulation at Saltfleetby alongside ROC's other pre-development projects offshore China, Australia and Mauritania," said ROC's chief executive officer Dr John Doran.

"The potential relevance of the Brinsley Abdy accumulation is best illustrated by the fact that if the higher end of the 2 to 3 million barrel estimate of recoverable oil reserves proves to be correct, ROC will book a net increase in reserves not dissimilar to that which it hopes to be able to book if the Chinguetti Oil Field, offshore Mauritania, proves to be commercial."