Russian oil company Zarubezhneft plans to continue drilling in deepwater areas off Cuba "in the next few days," using a Norwegian rig that is on the island, state media reported, citing state-owned Cubapetroleo.

The wells drilled this year in Cuba's offshore exploration areas have not yielded commercially viable quantities of petroleum.

Zarubezhneft has moved the semisubmersible Songa Mercur rig, which is owned by Norway's Songa Offshore, to Cuba's north-central coast, the official Granma newspaper said.

"In this case, it has to do with drilling of the L-01X exploratory well in the referenced zone, an action that will be executed under the framework of an exploration contract with the Russian oil company Zarubezhneft," Cubapetroleo said in a statement.

Drilling is expected to take place for about six months at the "deepest" of the wells drilled so far in Cuban waters, reaching 6,500 meters (21,311 feet), officials said.

The government estimates Cuba's offshore oil reserves at about 20 billion barrels, while other estimates put the figure at between 5 billion and 9 billion barrels.

Russian officials said at meetings held this year that they planned to expand investment in Cuba's energy and electric utility industries.

Zarubezhneft, according to reports, plans to invest $2.9 billion by 2025 in the Cuban fields developed by Soviet-era specialists. EFE