Oil giant Shell has completed a stage of oil and gas exploration in the Silistar offshore block, in Bulgaria's Black Sea zone.

Shell Exploration & Development will analyze the result of seismic studies to decide whether or not to drill into the seabed, Capital.bg reports.

Progress in the neighbouring block in Turkish waters, where Shell is looking for gas together with Turkish Petroleum, is a source of optimism after a sucessful drilling.

With a surface of 7000 square kilometers, Silistar is available to Shell for exploration for a period of five years, with the option of two extensions by two years each.

Last year, Total announced oil had been found in the nearby Khan Asparuh block, where the French company is looking for fossil fuels alongside OMV and Repsol.