A spokesperson for Azerbaijan's state-owned oil company Socar said they could not estimate the exact size of the discovery, but added the Japanese consortium would determine the project's potential commercial viability and profitability after further drilling.

The consortium - comprising of the Japanese Petroleum Exploration, Itochu Corp. and INPEX - declined to comment on the latest drilling results.

The consortium decided last June to stop drilling its first offshore test well at Atashkyah due to technical problems and high pressure in the well.

The Japanese Azerbaijan Oil Company holds 50% of the Atashkyah project with Socar holding the other 50%.