HOUSTON — The once mighty oil industry is shrinking quickly around the world, hunkering down in survival mode.

With the coronavirus pandemic all but eliminating travel and commutes, demand for energy is tumbling, and oil companies from Algeria to West Texas are slashing budgets. Refineries are cutting production of gasoline, diesel and jet fuel. Pipeline operators are telling producers that they can ship crude only if there is a buyer willing to take the fuel because storage tanks are filling up fast. And American oil companies are dropping rigs, dismissing fracking crews and beginning to shut down wells.

As much as 20 percent, or 20 million barrels a day, of oil demand may be lost as the global economy slows, according to the International Energy Agency. That is roughly equivalent to eliminating all U.S. consumption. To make matters worse, Saudi Arabia and Russia are increasing oil production to regain market share from American oil companies that increased production and exports in recent years.

The Trump administration has been trying to convince Saudi Arabia and Russia that they should cut production to help stabilize the oil market; President Trump and President Vladimir V. Putin of Russia discussed energy markets in a call on Monday. But the energy demand destroyed by the virus now overshadows anything that Saudi Arabia or Russia could do to reduce exports.