New drilling technologies for shale deposits helped contribute to the gains realized in the United States.
Eni, in its 150-page World Oil and Gas Review, said global natural gas production has increased by 1.8 percent since last year's report. It said Monday the United States "has become the biggest natural gas producer in the world."
Eni's figures for Dec. 31 show the United States was in the No. 5 position behind Turkmenistan, Qatar, Iran and Russia in terms of reserves. With 2.35 trillion cubic feet of natural gas produced as of Dec. 31, the United States leads Russia, which saw production decline 2.5 percent last year.
For oil, Eni said last year production increased overall by 2.9 percent because of an increase from Saudi Arabia and Libya. Libya's oil production collapsed during its civil war in 2011. The Italian energy company said U.S. oil production surged 12 percent last year, "which has more than compensated for shortfalls from other countries, particularly Iran."
Oil consumption increased last year by 1 percent.