For the fifth year in a row, US crude oil proved reserves have increased, while US natural gas proved reserves have increased to an all-time high, according to information released today by the US Energy Information Administration (EIA).
In 2013, the US saw a 9% increase in US proved oil reserves (a net addition of 3.1 billion barrels), and US natural gas proved reserved increased 10% to a record 354 trillion cubic feet (tcf). The increase more than makes up for the 7% decline in natural gas proved reserves seen in 2012, the EIA noted.
While Texas remains the state with the largest proved reserves of oil, North Dakota led in additions of oil reserves (adding almost 2 billion barrels of proved oil reserves in 2013, a 51% increase from 2012) because of development of the Bakken and Three Forks formations in the Williston Basin. North Dakota’s proved oil reserves surpassed those of the federal offshore Gulf of Mexico for the first time in 2013.
Texas had the second largest increase, adding 903 million barrels of proved oil reserves in 2013. Extensions to fields in the liquids-rich section of the Eagle Ford shale play in south-central Texas (Railroad Commission Districts 1 and 2) and to oil fields in the Permian Basin (Districts 7C and 8) provided the largest portion of new Texas proved oil reserves.
Pennsylvania and West Virginia reported the largest net increases in natural gas proved reserves in 2013, driven by continued development of the Marcellus Shale play, the largest US shale gas play based on proved reserves. Combined, these two states added 21.8 tcf of natural gas proved reserves in 2013 (13.5 tcf in Pennsylvania and 8.3 tcf in West Virginia) and were 70% of the net increase in proved natural gas reserves in 2013. US production of both oil and natural gas increased in 2013: Production of crude oil and lease condensate increased 15% (rising from 6.5 to 7.4 million barrels per day), while US production of natural gas increased 2% (rising from 71 to 73 billion cubic feet per day).
EIA's estimates of proved reserves are based on an annual survey of domestic oil and gas well operators.