Exxon cuts 3 bn barrels from oil reserves

Exxon Mobil cut its proved oil reserves by three billion barrels to 20 billion barrels at the end of 2016, the company announced Wednesday.

"As a result of very low prices during 2016, certain quantities of liquids and natural gas no longer qualified as proved reserves under SEC guidelines," the company said in a statement.

In an earnings report in October, the oil giant warned that a reserve cut might be coming, and Wednesday's announcement confirmed the reduction included "the entire 3.5 billion barrels of bitumen at Kearl in Alberta, Canada."

The reductions were partially offset by additions of oil and natural gas equivalent to about a billion barrels of oil in the United States, Kazakhstan, Papua New Guinea, Indonesia and Norway.

"These revisions are not expected to affect the operation of the underlying projects or to alter the company's outlook for future production volumes," the company said.