Brent crude oil was last up 2.1% at $43.82 a barrel, above where it was before talks about a production freeze collapsed over the weekend. Analysts said oil prices drew support on Tuesday from a strike by oil workers in Kuwait, reducing concerns about a global glut of supply.

The Russian camp was locked in negotiations with the Saudis, Qataris and Venezuelans — a core group that had first backed the freeze in February.

Thousands of workers in six oil and petrochemical companies went on strike Sunday to protest proposed government cutbacks.

Now the two sides, buyer and seller, will have to make do without the safety-net the contracts offered: high gas demand translates into high gas prices for the customers, while indexation to low oil prices would have deprived Gazprom of the upside of a temporary supply glitch or a prolonged cold winter.

Some 18 OPEC and non-OPEC countries, including Russia, had been meant to meet on Sunday morning in the Qatari capital of Doha and rubber-stamp a deal - in the making since February - to freeze output at January levels until October 2016.

“A flat output profile for OPEC (excluding Iran) and Russia would tighten global balances by almost 0.5 million barrels a day in the second half relative to our expectations and push the oil market into a deficit in the third quarter,” the U.S. bank wrote in a note on Wednesday. That would “push prices above $50 near term,” it said.

The contango between futures prices in the fourth quarter of 2016 and the average of 2017 has shrunk from $3.75 per barrel in December to $2.50 at the end of February and just $1.65 in recent days.

North Sea Brent crude oil prices averaged $38/barrel (b) in March, a $6/b increase from February. Both Brent and West Texas Intermediate (WTI) crude oil prices are forecast to average $35/b in 2016 and $41/b in 2017. However, the current values of futures and options contracts suggest high uncertainty in the price outlook.

“The oil price is growing. I think everyone is expecting the successful outcome of our work,” Mr Sechin said. “We will need higher price levels than $45 or even $50 a barrel.”

"Now we're seeing reductions in spending on shorter cycle projects, in other words immediate drilling activity," Watson said. "Rig rates in the US are down almost 80%, we're seeing decline in rig rates around the world and we're starting to see the supply response that everyone has expected. So we're seeing the markets come back into better balance [but] it may take more time."

"The level of $45-50 (per barrel) is acceptable from the point of view of market balance: if prices go higher shale oil production could start to recover."

Oil-producing countries can come to an agreement capping crude production at January levels even if Iran doesn’t join the move to help shore up prices.

Oil at $35 a barrel is neither too high nor too low but just right to make shares of U.S. explorers worth buying, according to Goldman Sachs Group Inc.

The cumulative effect suggests that for U.S. growth over the next three years, there's no difference between oil at $30 or $70 per barrel. How the trade balance responds to swings in crude will dictate which path is more desirable.

State-run Saudi Arabian Oil Co. increased its official selling price for May Light, Medium and Heavy sales to U.S. buyers by 40 cents a barrel, the company said in an e-mailed statement Tuesday. Extra Light crude will sell at a premium of $2.60 a barrel to the regional benchmark, 75 cents higher than the differential in April. For the U.S., the benchmark is the Argus Sour Crude Index.