Oil companies operating in Norway expect to spend 153.2 billion kroner ($18.47 billion) on exploration and production next year, the weakest figure since 2011 and nearly a third below the sector’s all-time high of NOK220.7 billion two years ago. In 2016, they expect to spend NOK165.9 billion on exploration and production, down from NOK195.4 billion a year earlier and 1% below a similar estimate made in February.

Brent futures rose 50 cents to $49.11 a barrel, having closed 26 cents up previously to snap a four-day slide.

Now, under the economic plan known as Vision 2030 promoted by the king’s powerful son, Deputy Crown Prince Mohammed bin Salman, the government is signaling it wants to wean the kingdom’s economy off oil revenue, lessening the need to manage prices.

“But when you sign agreements and create the impression that it’s going to be implemented when no one’s identified the trillions of dollars that it’s going to cost, it’s just not clear that’s going to deliver.”

Speaking from his high-rise office in the capital, Doha, Mohammed bin Saleh al-Sada said a minimum price of $65 a barrel is "badly needed at the moment." He cautioned that the security of future supplies is as risk because of the price slump that has squeezed oil producers since 2014.

"If collectively we find a way to stay within the 2 degree (Celsius limit), we will still need significant investment in oil and gas. I am not talking about a few millions, I am talking about up to a trillion dollars every year that industry has to invest just to stay within 2 degrees in oil and gas," Ben van Beurden said at the company's annual shareholder meeting in The Hague.

The sharp drop in oil prices over the past two years has led companies including Exxon Mobil and Royal Dutch Shell to sharply reduce budgets, particularly for exploration, where spending fell in 2015 to around 95 billion from $168 billion two years earlier, according to Morgan Stanley.

For the United States and Russia, total petroleum and natural gas hydrocarbon production, in energy content terms, is almost evenly split between petroleum and natural gas. Saudi Arabia's production, on the other hand, heavily favors petroleum. Total petroleum production is made up of several different types of liquid fuels, including crude oil and lease condensate, tight oil, extra-heavy oil, and bitumen. In addition, various processes produce natural gas plant liquids (NGPL), biofuels, and refinery processing gain, among other possible liquid fuels.

"Currently, Iran's crude oil exports, excluding gas condensates, have reached 2 million barrels per day (bpd)," Javadi said. "Iran's crude oil export capacity will reach 2.2 million barrels by the middle of summer."

India said Monday it will invest up to $500 million in a deal to develop a strategic port in Iran and both countries planned a number of projects they say are worth hundreds of millions of dollars.