Chapter 2 details the differences and similarities among twenty-first-century petroleum resources and distinguishes conventional from unconventional resources. The chapter argues that, while these definitions are muddled, there is value to understanding and parsing unconventional oil and gas. Numerous different oil and gas resources are then surveyed, including shale gas, ultradeep gas, Arctic gas, tight gas, coalbed methane, biogas, acid gas, geopressurized gas, methane hydrates, condensates, light tight oil, extra-heavy oil, ultradeep oil, Arctic oil, depleted oil, kerogen, biofuels, gas-to-liquids, and coal-to-liquids. Estimates are provided of cumulative industry greenhouse gas emissions for conventional versus unconventional oil and gas resources. The chapter concludes with a discussion of hydrogen—the ultimate unconventional resource—and its production pathways.
Assessment of global unconventional oil and gas resources
