Assessments regularly change based on our understanding of geology, as well as advances in technology.
As more is learned about the geology of a given formation, both from USGS research and from industry activity, a clearer picture of the potential recoverable oil and gas resources can be created.
In some cases, industry activity can show that a rock formation that was previous thought to have significant quantities of oil and gas does not. In other cases, advances in research techniques and tools can show a rock formation is more likely to have the conditions necessary to produce oil and gas.
A major source of changes in USGS assessments was the advent of production from continuous resource accumulations, such as shale and other “tight” or impermeable formations.
Learn more: USGS Energy Assessments
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- FAQ
How is hydraulic fracturing related to earthquakes and tremors?
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There isn’t really a “typical” fractured well because the amount of water used depends on the rock formation, the operator, whether the well is vertical or horizontal, and the number of portions (or stages) of the well that are fractured. In addition, some water is recycled from fluids produced by the well, so the net consumption might be smaller at sites that recycle.Water use per well can be...
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National assessment of carbon dioxide enhanced oil recovery and associated carbon dioxide retention resources — Summary
IntroductionIn 2020, the U.S. Geological Survey (USGS) completed a probabilistic assessment of the volume of technically recoverable oil resources that might be produced by using current carbon dioxide enhanced oil recovery (CO2-EOR) technologies in amenable conventional oil reservoirs underlying the onshore and State waters areas of the conterminous United States. The assessment also includes estAuthorsPeter D. Warwick, Emil D. Attanasi, Madalyn S. Blondes, Sean T. Brennan, Marc L. Buursink, Steven M. Cahan, Colin A. Doolan, Philip A. Freeman, C. Özgen Karacan, Celeste D. Lohr, Matthew D. Merrill, Ricardo A. Olea, Jenna L. Shelton, Ernie R. Slucher, Brian A. VarelaNational assessment of carbon dioxide enhanced oil recovery and associated carbon dioxide retention resources — Results
In 2020, the U.S. Geological Survey (USGS) completed a probabilistic assessment of the volume of technically recoverable oil resources available if current carbon dioxide enhanced oil recovery (CO2-EOR) technologies were applied to amenable oil reservoirs underlying the onshore and State waters areas of the conterminous United States. The assessment also includes estimates of the mass of CO2 thatAuthorsPeter D. Warwick, Emil D. Attanasi, Madalyn S. Blondes, Sean T. Brennan, Marc L. Buursink, Steven M. Cahan, Colin A. Doolan, Philip A. Freeman, C. Özgen Karacan, Celeste D. Lohr, Matthew D. Merrill, Ricardo A. Olea, Jenna L. Shelton, Ernie R. Slucher, Brian A. VarelaAssessment of undiscovered oil and gas resources in the Cretaceous Nanushuk and Torok Formations, Alaska North Slope, and summary of resource potential of the National Petroleum Reserve in Alaska, 2017
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From 2000 to 2011, the U.S. Geological Survey conducted 139 quantitative assessments of continuous (unconventional) oil and gas accumulations within the United States. This report documents those assessments more fully than previously done by providing detailed documentation of both the assessment input and output. This report also compiles the data into spreadsheet tables that can be more readilyAuthorsAssessment of undiscovered technically recoverable oil and gas resources of Puerto Rico and the Puerto Rico-U.S. Virgin Islands Exclusive Economic Zone, 2013
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The U.S. Geological Survey (USGS) has completed an assessment of the volumes of undiscovered, technically recoverable oil and gas resources in conventional and continuous accumulations in Cook Inlet. The assessment used a geology-based methodology and results from new scientific research by the USGS and the State of Alaska, Department of Natural Resources, Division of Geological and Geophysical SuAuthorsRichard G. Stanley, Brenda S. Pierce, David W. HouseknechtAssessment of Undiscovered Technically Recoverable Oil and Gas Resources of the Bakken Formation, Williston Basin, Montana and North Dakota, 2008
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The U.S. Geological Survey (USGS) recently completed an assessment of the undiscovered conventional oil and gas potential of 128 of the world’s petroleum provinces (U.S. Geological Survey World Energy Assessment Team, 2000). In each province, the USGS defined Total Petroleum Systems, and Assessment Units in each Total Petroleum System, and then quantitatively estimated the undiscovered conventionaAuthorsThomas S. Ahlbrandt, R. M. Pollastro, Christopher J. SchenkUSGS world petroleum assessment 2000; new estimates of undiscovered oil and natural gas, including reserve growth, outside the United States
Oil and natural gas account for approximately 63 percent of the world’s total energy consumption. The U.S. Geological Survey periodically estimates the amount of oil and gas remaining to be found in the world. Since 1981, each of the last four of these assessments has shown a slight increase in the combined volume of identified reserves and undiscovered resources. The latest assessment estimates tAuthors - News