The FINANCIAL — Since production began around 1930, the Buda Limestone has produced 204 million barrels of oil, 10 days’ U.S. consumption at the 2025 rate, and 287 billion cubic feet of gas, three days’ consumption for the United States. The Eagle Ford Group, one of the most abundant sources of U.S. energy, lies above the Buda and is the primary source for its undiscovered oil and gas.
“The U.S. economy and our way of life depend on energy, and USGS oil and gas assessments point to resources that industry hasn’t discovered yet. In this case, the Buda Limestone has little remaining undiscovered oil or gas, indicating a need for new resources,” said USGS Director Ned Mamula.
USGS oil and gas assessments began 50 years ago following an oil embargo against the U.S. that signaled a need to understand the occurrence, distribution and potential volumes of undiscovered resources. The embargo led to a mandate for the USGS to use geologic science and data to assess undiscovered oil and gas resources to help meet the nation’s needs. The work continues today – identifying new resources for domestic production as well as international resources that affect market conditions — an important part of the USGS mission to provide actionable insight to U.S. leaders, other Federal agencies, industry and the public.
USGS energy resource assessments provide information to policy makers on resource potential in areas of the U.S. and the world. For land-management agencies such as the Bureau of Land Management, the results of an energy resources assessment feed into land-use and resource management plans. For the private sector, USGS assessments of undiscovered energy resources provide context for planning detailed exploration.
The USGS Energy Resources Program assesses the potential for undiscovered oil and gas resources in priority geologic provinces in the United States and around the world. Two methodologies are used by the USGS: one for assessing conventional oil and gas resources and one for assessing unconventional (continuous) oil and gas resources (such as shale gas and coalbed gas).
The fact sheet on the Buda Limestone Oil and Gas Assessment is available here.