Source: U.S. Energy Information Administration,

Note: Crude oil production includes lease condensate. U.S. Energy Information Administration, Petroleum Supply Monthly Crude oil production includes lease condensate.

U.S. crude oil production exceeded an average 7 million barrels per day (bbl/d) in November and December 2012, the highest volume since December 1992. The end-of-year data were reported on February 27 in EIA's Petroleum Supply Monthly.

Increasing oil production in North Dakota and onshore Texas drove the increase in U.S. crude oil production over the last several months (although crude oil production in North Dakota took a dip in November, before increasing again in December). Much of the increase in crude oil production is coming from shale and other tight (very low permeability) formations.

Initial estimates for production in November were below 7 million bbl/d, but revisions based on additional data indicate that production exceeded 7 million bbl/d in November 2012. That was followed by December production estimated to be more than 7 million bbl/d.

Because of time constraints in publishing monthly petroleum supply statistics, EIA uses an estimate of production for the most recent month. This estimate is derived from actual data reported by federal and state agencies that supply the information in time for EIA's publication. For remaining states, EIA estimates crude oil production using the latest available data from those states. As reported data become available, EIA revises the estimated production data with actual production data. The revised data appear in the historical data series on EIA's website. In the future, EIA is proposing to collect crude oil production data directly from companies in the top-producing states in order to provide a more accurate and timely assessment of U.S. crude oil production volumes.