Tracey J. Mercier Phuong A. Le Andrea D. Cicero Ronald M. Drake II Thomas M. Finn Sarah E. Gelman Jane S. Hearon Benjamin G. Johnson Jenny H. Lagesse Heidi M. Leathers-Miller Kira K. Timm Christopher J. Schenk 2025 <p>Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 34.3 billion barrels of oil and 320 trillion cubic feet of gas in the Greater Caspian area.</p> application/pdf 10.3133/fs20243047 en U.S. Geological Survey Assessment of undiscovered conventional oil and gas resources of the Greater Caspian area, 2022 reports