The companies insist they're trying to find new oil that might help bring down gas prices, but the money they spend on exploration is nothing compared with what they spend on stock buybacks and dividends.
It's good news for shareholders, including mutual funds and retirement plans for millions of Americans, but no help to drivers already making drastic cutbacks to offset the high cost of fuel.
The five biggest international oil companies plowed about 55 percent of the cash they made from their businesses into stock buybacks and dividends last year, up from 30 percent in 2000 and just 1 percent in 1993, according to Rice University's James A. Baker III Institute for Public Policy.
The percentage they spend to find new deposits of fossil fuels has remained flat for years, in the mid-single digits.
The issue has become more sensitive as lawmakers and Americans frustrated by high gas prices have balked at gaudy reports of oil industry profits. ConocoPhillips is scheduled to kick off the latest round of Big Oil earnings reports Wednesday.
Oil prices are set on the open market, not by the oil industry. But that hasn't stopped public protests, a series of congressional grillings for top oil executives, and a failed attempt by lawmakers to slap Big Oil with a windfall profits tax.
In the first three months of this year, Exxon Mobil Corp., the world's biggest publicly traded oil company, shelled out $8.8 billion on stock buybacks alone, compared with $5.5 billion on exploration and other capital projects.
ConocoPhillips has already told investors that its stock buybacks for April to June of this year will come to about $2.5 billion - nine times what it spent on exploration.
Stock buybacks are common throughout corporate America, not just for Big Oil. They shrink the amount of stock on the open market, essentially increasing its value and giving individual shareholders a bigger stake in the company.
But some critics say Big Oil focuses too much on boosting stock prices, in an industry that sometimes ties executive pay to stock price.
And in focusing on buybacks and dividends over exploring for new oil, some critics say, oil companies jeopardize its already dwindling share of world supply.
"If you're not spending your money finding and developing new oil, then there's no new oil," said Amy Myers Jaffe, an energy expert at Rice University who's studied spending patterns of the major oil companies.