The amount of ultimately recoverable crude oil is found to be 181.1 billion bbl for the conterminous U.S. (including offshore). Inclusion of Alaska raises the total to 217.2 billion bbl. © 1994.
Heffington, W. M., & Brasovan, M. W. (1994). Prediction of U.S. crude oil-production using growth curves. Energy, 19(7), 813–815. https://doi.org/10.1016/0360-5442(94)90020-5