Royal Dutch Shell wants to expand its Russian operations and add a third big project, despite a huge cost overrun at its Sakhalin Energy venture.
The firm's Russia chairman Chris Finlayson said: "I'm looking for a substantive increase in the size of the business, both in Sakhalin and in west Siberia and potentially a third platform.
"I think it will be a platform which is based on remote areas, strong technology input, probably Arctic, but a range of different options."
Shell is still smarting from ballooning costs at Sakhalin, a huge liquefied natural gas project off Russia's Pacific coast.
It doubled the Sakhalin cost estimate from $10 billion (£5.7 billion) to $20 billion (£11.5 billion) last July, dismaying shareholders and angering the Russian government, which says it will now have to wait much longer before it sees any share of the profit.
Shell has sent "truckloads" of documents to the Russian agency investigating the cost overrun, which Mr Finlayson said was caused by booming prices for inputs such as steel, the strength of the rouble and the project's complexity.
Another extra will be $300 million (£173 million) to re-route pipelines to avoid harming rare grey whales, a decision taken last year.
But Mr Finlayson said revised calculations carried out by top Rus-sian experts showed Sakhalin remained a very good deal for Russia even at a conservative oil price, and he expected the cost negotiations to end during the third quarter of the year.
The cost hike also jeopardised Shell's plan to swap 25 per cent of Sakhalin - out of its total 55 per cent
holding - for a half share of the massive deep deposits of Zapolyarnoye gas field, owned by Russian gas giant Gazprom.
Mr Finlayson did not put a figure on Zapo's gas and condensate reserves, which Shell wants to market in Europe, but indicated there was more in its deposits than Shell has in Sakhalin.
"We are not going to be doing deals which reduce our reserves," he said.
With the value of Sakhalin Energy slashed by the cost overrun, Shell and Gazprom will spend months haggling over the two sides of the swap.
Mr Finlayson said the firms' confidential memorandum of under-standing included a way of adjusting the value of the swap in case there was a difference in value.
One adjustment will be for Shell's minority partners in Sakhalin Energy, Japan's Mitsui and Mitsubishi, to give up some of their equity in the project, in which they hold 25 per cent and 20 per cent respectively.
"I think it's an excellent illustration of the strong alignment of the current shareholders in wanting to have Gazprom in this project," said Mr Finlayson.
It is not clear what the Japanese firms will get in return.
Despite the cost overrun and a delayed first delivery date, Sakhalin Energy has sold virtually all its production capacity and is looking to expand. Its infrastructure would allow four LNG production trains instead of the current two.
Mr Finlayson said: "Whilst clearly the company must focus on delivering the first two trains of this massive project, you don't sit and wait until that's completely finished before you start thinking about more than that."
Aside from Sakhalin, Shell is also looking for oil production opportunities, possibly expanding its west Siberian oil production joint venture, Salym Petroleum Development.
"We certainly have an aspiration to grow that position in west Siberia.
"Our preferred route is new field development rather than the purchase of mature assets. So we're on the lookout for more."
Salym, which is set to be producing around 165,000 barrels of oil per day by the end of the decade, is jointly owned by London-listed Sibir Energy, but Mr Finlayson said Shell had no plans to buy out its joint venture partner.
Much of Russia's oil production growth in the last 15 years has come from using technology to eke more out of existing fields, but Mr Finlayson said that trend would soon have to end.
"There are lots of undeveloped resources in Russia and the time is rapidly coming when attention will have to be paid to changing that exploration acreage into new development.
"That's where we're focusing at the moment," he said.
Shell was looking at the "whole periphery", including new areas of west Siberia, the undeveloped but remote fields of east Siberia and the Arctic, where changes in the sea ice were making the coast much more accessible and a likely home for another LNG terminal in the future, he said.
"We are keen on growing new positions over the short to medium term and starting to develop a third major platform in Russia. There are a number of things being looked at," he said.