Moscow (Platts)--27Jan2010/845 am EST/1345 GMT

Russia's biggest oil producer Rosneft has discovered a major oil field in East Siberian Irkutsk region, with the reserves estimated at 160.2 million mt (1.17 billion barrels) of crude, Russia's natural resources ministry said Wednesday.

"We can announce that the Sevastyanovo [or Savostyanovo according to Rosneft] field with reserves over 150 million mt of crude has been discovered," the natural resources minister Yuri Trutnev told Russia's Prime Minister Vladimir Putin, according to a script posted on the government website.

"This is a [so-called] strategic field," Trutnev said.

The field's C1 and C2 reserves are estimated at 160.2 million mt under Russian classification, a spokeswoman with the ministry said.

Russia's C1 and C2 category mainly correlate to probable reserves under international standards but do not correspond to it in full.

A spokesman with Rosneft said that discovery was made within the Mogdinsky licensed area in 2009.

The company has submitted documents on the discovery to Russia's commission on licensing, he said.

The spokesman, however, declined to say when the company expects to book the newly discovered reserves.

RUSSIA FULLY REPLACES OIL PRODUCTION WITH RESERVES IN 2009

At a meeting with Putin, Trutnev also said that Russia had explored 620 million mt of crude in new reserves in 2009, with the country's crude production amounting to 490 million mt in the period.

"This is a good result," he said.

Trutnev added that his ministry has aimed for similar results in replacement of the country's production with reserves this year.

Russia considers hydrocarbon fields with reserves of 70 million mt (511 million barrels) of oil and 50 billion cubic meters of gas as well as offshore fields as "strategic."

Under the law on foreign investments approved in mid-2008, only state-controlled companies--in which Russia has more than 50% stake--are allowed to develop such reserves.

--Nadia Rodova, nadia_rodova@platts.com