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."

BP has the lowest amount of pre-FID (final investment decision) resource, which leads to the weakest future growth rates.

CNPC and Mozambique’s national oil and gas company ENH have signed a cooperation framework agreement under which the two sides will reinforce cooperation in oil and gas exploration and production, and natural gas processing and marketing.

International Energy Agency (IEA) Executive Director Fatih Birol said last month that global upstream investment fell by 24 percent in 2015 and is set to fall by 18 percent in 2016.

Crude oil production fell 7.8 percent from April 2015 to average 8.9 million barrels per day in April, the lowest output level in 20 months. Natural gas liquids (NGL) production, a co-product of natural gas production, rose from prior year. NGL production in April averaged 3.3 million barrels per day, 0.7 percent higher than last year. This was the highest April output level on record.

Crude oil production in June from the seven major US shale regions is expected to fall 113,000 b/d month-over-month to 4.85 million b/d. Gas production from the regions is forecast to fall 464 MMcfd.

The Paris-based agency said global oil stocks will experience a “dramatic reduction” in the second half of the year, but also warned that they will continue to increase in the first half of the year as Iran ramps up its production, adding to the nearly two years of oversupply.

Russian oil and gas condensate production may reach 544.6 million tonnes this year, rising to 565 million tonnes in 2017.