Three companies eye deepwater gas drilling off Bulgaria

SOFIA, June 21 (Reuters) - Three oil and gas companies have filed bids in a tender to explore for a deepwater gas field off Bulgaria's Black Sea coast, after a successful gas discovery in a nearby site in Romanian waters, the energy minister said on Thursday.

The Balkan country, almost fully dependent on Russian natural gas supplies, is seeking ways to diversify its gas routes and sources to cuts costs and boost its energy security.

British-based Melrose Resources, already developing a number of smaller gas fields in the Black Sea shelf, and French group Total have placed bids, Delyan Dobrev told an energy forum.

U.S. operator Exxon Mobil, which had already announced a huge gas find at an offshore Black Sea well in Romanian waters together with Austrian peer OMV, also filed an offer to carry out exploration works at Khan Asparuh field, close to the Romanian field.

Dobrev said the ministry will pick a winner by the end of the month. Gas production could start in 3-4 years provided the exploration activities point to substantial gas reserves.

"Our hopes for a serious find are very high, as just 15 kilometres off the north border of our field, in Romanian waters, between 40 to 80 billion cubic metres (bcm) of gas were discovered," Dobrev said.

"If have a similar discovery, Bulgaria's domestic gas needs for 15-20 years will be fully covered," he said.

In February, OMV said it had discovered what could be up to 84 bcm of gas in the Neptun block, the biggest find in its history.

Bulgaria's Khan Asparuh block spans 15,000 square kilometres in the Black Sea. The waters are deep and the site is hard to explore.

Bulgaria consumer about 3 bcm of gas annually. (Reporting by Tsvetelia Tsolova; Editing by Dan Lalor)