Here are the 3 key times the U.S. tapped into its massive...

Here are the 3 key times the U.S. tapped into its massive emergency oil reserves

Trump has authorized release in wake of Saudi attack; Perry says it’s still ‘premature’

The weekend attack on major crude-oil facilities in Saudi Arabia could prompt an occurrence that has come about only three times in the past: an emergency release from the U.S. Strategic Petroleum Reserve.

President Donald Trump said he’d authorized tapping the so-called SPR in response to the attack, “if needed,” to keep oil markets CLV19, -1.69% BRNX19, -1.45% supplied and to moderate a price spike that could harm consumers and corporations.

Energy Secretary Rick Perry, speaking Monday on CNBC, said it was premature to discuss using the reserve, which now holds about 645 million barrels of oil, according to the Energy Department. The U.S. stockpile of crude is believed to be the largest such reserve in the world.

While there have been sales and exchanges for nonemergency reasons, the SPR, set up in the mid-1970s amid the Arab oil embargo, has been used for emergency purposes only three times, in 1991, 2005 and 2011.

Here’s a look at each one of those actions:

Now see: Why Saudi Arabia’s output hit won’t lead to shocking prices at the gas pump.

www.marketwatch.com