Published estimates in the US Energy Information Administration’s (EIA) report; US Crude Oil and Natural Gas Proved Reserves, 2011, indicate that proved crude oil additions set a record increase for the second year in a row.
Natural gas proved reserve additions displayed the second largest annual increase since 1977, but fell short of setting a record.
Crude oil reserves rose 15% (approximately 3.8 million bbl) to the highest level since 1985. Natural gas reserves were up approximately 10% (31.2 trillion ft3).
Proved oil reserves increased 29 billion bbl, marking the third consecutive annual increase and highest volume of proved reserves since 1985.
Proved reserves in tight oil plays accounted for 3.6 billion bbl (13%) of total proved reserves of crude oil and lease condensate in 2011.
Texas recorded the largest increase in oil reserves among the states, largely due to continuing development in the Permian Basin and the Eagle Ford formation in the Western Gulf Basin.
North Dakota experienced the second largest increase, due to development activity in the Bakken formation in the Williston Basin.
Natural gas proved reserves increased by approximately 10% in 2011, reaching 348.8 trillion ft3. This rise represented the 13th consecutive annual increase.
Texas and Pennsylvania are responsible for 73% of the net increase. Pennsylvania's proven natural gas reserves more than doubled in 2010, and increased by an additional 12.7 trillion ft3 in 2011.
Proved reserves in shale gas plays accounted for 131.6 trillion ft3 (38%) of total proved reserves of wet natural gas in 2011.
Adapted from a press release by Emma McAleavey.
Read the article online at: https://www.hydrocarbonengineering.com/gas-processing/02082013/us_proved_oil_reserves_up528/