EIA: “In 2011, oil and gas exploration and production companies operating in the United States added almost 3.8 billion barrels of crude oil and lease condensate proved reserves, an increase of 15 percent, and the greatest volume increase since the U.S. Energy Information Administration (EIA) began publishing proved reserves estimates in 1977. Proved reserves of crude oil and lease condensate increased by 2.9 billion barrels in 2010, the previous record. Proved reserves of U.S. wet natural gas rose by 31.2 trillion cubic feet in 2011 to a new record high of 348.8 trillion cubic feet. Though this increase was lower than the 33.8 trillion cubic feet (Tcf) added in 2010, it was only the second year since 1977 that natural gas net reserves additions surpassed 30 Tcf.”