The U.S. Department of Energy said on Feb. 8 it will sell 10 million barrels (MMbbl) of oil from the government's emergency crude reserve in late February.

The sale from the Strategic Petroleum Reserve (SPR) was required by a law passed in 2016 as a way to help increase funding for medical research. The law mandated sales of 25 MMbbl from the SPR over three years, starting with the sale of 10 MMbbl in 2017.

The SPR, which is a series of heavily guarded underground salt caverns along the coasts of Texas and Louisiana, currently holds about 690 MMbbl of mostly sour oil, a type containing high sulfur that many U.S. refineries can process.

This will be the second sale of oil from the emergency stash in 2017--in January., Shell bought 6.2 MMbbl from the reserve and Phillips 66 bought 200 Mbbl.

The federal government held that sale to fund a modernization of the SPR. More sales are expected be held in coming years to fund up to $2 billion for the revamp.