BP and Shell will together make record profits of more than US$68 billion ($86.77 billion) this year if the oil price stays at current levels, say City of London forecasters.
Brent crude soared to US$116 a barrel on Friday as BP shut down a key North Sea pipelineahead of industrial action and a strike at Exxon in Nigeria disrupted production.
Oil companies are profiting at a time when motoring and consumer organisations are complaining about the price of petrol, which has hit 5 ($12.65) a gallon.
BP and Shell will this week report record profits for the first quarter thanks to an oil price that has stood at an average of US$110 a barrel since the start of the year.
Richard Griffiths, of broker Evolution Securities, says BP can expect to see extra operating profit of US$400 million for every one-dollar rise in the price of crude.
If the futures market is correct and the oil price remains high, he says a "back-of-the-envelope calculation" will see BP record an annual after-tax profit of US$32 billion, while Shell would notch up US$36 billion.
Oil and gas prices have been driven higher by a two-day strike at Scotland's Grangemouth refinery. The strike has stoked fears of fuel shortages in Scotland and the north of England and there are reports of panic buying by Scottish motorists.
Trade union Unite said its members had received a letter from Grangemouth's owner, Ineos, saying the company's final salary pension scheme would be closed to new members from August. Conciliation talks broke down last week. Union officials accused Ineos of being "incendiary" rather than conciliatory; company officials warned of the effects of a strike on the UK economy.
A strike at Exxon in Nigeria had halted output of 200,000 barrels a day.
