The United States hold a strategic reserve of oil.

https://www.energy.gov/fe/services/petroleum-reserves/strategic-petroleum-reserve/spr-storage-sites

America began setting aside emergency reserves of crude oil, the largest in the world, after the 1973 oil embargo by Arab members of the Organization of Petroleum Exporting Countries, or OPEC, triggered an oil crisis and sent the U.S. economy into recession. President Gerald Ford signed legislation in 1975 to establish a strategic reserve that would hold up to 1 billion barrels of oil to mitigate the damage from any future shortages in global supply. The Strategic Petroleum Reserve currently has about 645 million barrels of crude stored deep across four underground caverns created in salt domes along the Texas and Louisiana Gulf Coasts. Maintained by the Department of Energy, the caverns can hold up to 727 million barrels of crude. The stockpile is sufficient to cover “the equivalent of 143 days of import protection.”

What is the value of this crude ?

Today, crude trades are $68.78  a barrel.

So, what is the value of the current inventory of the US Strategic Petroleum Reserve ?

$68.78 a barrel x  645,000,000 = $44,363,100,000

That is $44bn.