An interesting paper was published by S.H. Mohr, J. Wang , G. Ellem , J. Ward , and D. Giurco in Feb 2015 entitled, Projection of world fossil fuels by country . It updates Steve Mohr’s earlier work in 2010 and can be found at the link below. https://www.researchgate.net/profile/Steve_Mohr The table below is table 2 from page 124 of the paper which summarizes the URR estimates with comparisons to Mohr’s earlier estimates from 2010. The best guess (BG) and High URR estimates both include considerable quantities of kerogen and gas hydrates. Both comments below discuss the high case for oil and natural gas. From page 127 (section 5.2.2): The projection is heavily dependent on the rapid growth in kerogen oil in the USA. Historically kerogen minerals were exploited for synthetic oil production such as in Australia, and kerogen is currently exploited in Estonia as an energy source for power […]