There are many underlying forces of energy markets that cannot be known with certainty, such as the speed of technological development, the impact of variations in oil prices, changes in legislation, and impacts of the economy on supply and demand. The USGS resource estimates, on which the production estimates are based, have a sizeable range of uncertainty around them, of which readers should be aware. To allow timely completion of this study, simplifying assumptions were made which add to the uncertainty of the projections. For example, production schedules were postulated without specifying the effect of various levels of oil prices and technology advancements. Rapid technology growth can yield lower costs and faster development, with the reverse effect given slower technology growth.
Oil price is a key factor in determining when production becomes economic.