Estimating undiscovered oil resources: An engineering approach

This paper is an evaluation of the earlier work of M.K. Hubbert with the aim of more objectively estimating total recoverable (i.e. producible) oil in the United States and Nigeria. The results, based upon an engineering model, indicate that 198 billion barrels are ultimately recoverable in the United States of which 113.8 billion barrels have been produced through 1977. For Nigeria, 19.4 billion barrels are ultimately recoverable of which 6.1 billion barrels have been produced at the end of 1977.