Lord Browne: "There are huge reserves and resources for the future."

"Russia is the prime oil and gas province in the world," BP chief executive Lord Browne told the BBC.

The sheer size of Russia's oil industry is enough to make it vital for BP to be involved, Lord Browne believes.

Russia pumps out almost 8m barrels of oil a day, roughly on par with Saudi Arabia, as well as about 10m barrels of gas, he said.

"It does actually put Saudi Arabia in the shade. And, off course, Saudi Arabia puts everybody else in the shade.

"It's the obvious place for the oil and gas industry to be present in."

Leading player

In August, BP completed a $6bn (�3.6bn) deal to set up a 50/50 joint venture with TNK, the third largest oil company in Russia.

BP views Russian actions with "less and less" suspicion

According to BP, the deal made it the world's second largest oil company, and when it was first announced in February it was to be the biggest ever foreign investment in Russia.

Since then it has been overtaken by an even bigger investment in Russia by BP's rival, Shell.

Suspicion

BP's Russian presence may be necessary and desirable, but it has not been comfortable and easy.

Merging BP's and TNK's business cultures has been an uphill struggle, Lord Browne acknowledged.

"The standards [in Russia] have been different, but they are certainly moving," he said.

"Our relationship with our partners started with a massive disagreement and conflict," Lord Browne said.

But since then, things have improved.

"The partnership is developing very well, the political environment is developing very well.

"We less and less view each other's actions with suspicion."

Bright future

Lord Browne stressed that BP is in Russia for the long-term.

"There are huge reserves and resources for the future," he said.

Analysts say BP must crack the technological challenges in Russia

"There are 21bn barrels of oil and gas that we haven't even put into our reserves; it's called resources for the future."

Analysts seemed optimistic about the future too.

"There is clearly upside here, if BP can crack the technological and 'Russian' challenges," wrote Deutsche Bank analyst JJ Traynor in a report.

"BP's new Russian partners [come] across as serious long-term players, and the overall technical programme looks robust," he noted.

Risks

BP's Russian venture represents about 15% of the oil it produces, and the energy giant is keen to make sure this proportion does not rise too fast.

Deutsche Bank's JJ Traynor has warned that already there is a risk that "Russia becomes overplayed in the share price, and absorbs too much management and marketing time".

Deutsche Bank's research quantified the "real Russian risk" as about "3-4% of net income and 2-3% of cashflow".