The five mammoth oil firms that together comprise the entity called 'Big Oil' reported massive profits during 2018 despite volatile oil prices and geopolitical uncertainties.

Chevron Corporation, Exxon Mobil Corporation, BP plc, Royal Dutch Shell plc and Total S.A. as a group posted more than $80 billion in net profits last year. Also called 'supermajors', these five firms saw their bottom lines hit levels not seen since crude oil rose above $100 per barrel in 2014.

Thereafter, oil prices the plummeted by half in less than a year in 2015, reaching lows not seen since the Great Recession of 2008 due to the strong U.S. dollar and OPEC refusing to boost prices by limiting production. It's an established fact that when the value of the dollar is strong, the value of commodities falls.

Analysts said higher oil prices towards the end of 2018 helped fuel the revenue and profit surge despite unnerving price volatility. On average, the price of Brent crude in 2018 came to $71 per barrel compared to only $54 in 2017.

Massive cost-cutting aligned with equally severe cuts in investments also helped strengthen Big Oil's profits in 2018. Investments in exploration and production rose seven percent last year to $382 billion, but were still 40 percent below their 2014 peak. Most of these investments are in the U.S.

But maintaining pricing and production discipline will be key to determining if Big Oil can do better this year.

"Total's job is to be profitable and to lower the break-even point no matter what the price of oil is," said CEO Patrick Pouyanne. He expects Big Oil "to maintain discipline" in the market this year.

Unlike 2015, the motive forces behind the rise in crude prices in 2018 was the decision of OPEC + (or OPEC + Russia and others) in early December to reduce supply by 1.2 million barrels a day in the first half of 2019.

Oil industry analysts estimate the production cut announced by OPEC+ will likely be enough to balance the market in the first half of 2019 and prevent inventories from stockpiling and causing a glut.

More worryingly, Saudi Arabia will hit the United States with a huge oil export cut this year. Oil industry sources said the Saudis might ship only 582,000 barrels of crude a day to the U.S. in 2019, which will be lower than the 30-year low set in 2017. Saudi Arabia exported 860,000 barrels a day of crude to the U.S. in 2018.

The Saudis earlier informed U.S.-based oil refiners to expect much lower shipments starting January. Total Saudi exports are estimated to have plunged to 7 million barrels a day in January compared to 8 million barrels a day from November to December 2018.