Abstract

Crude oil originally in place in the United States and adjoining continental shelf is estimated at 1,600 billion barrels. One thousand billion barrels of this oil will be found by exploration, and 400 billion barrels will be economically producible. The remaining 1,200 billion barrels is in undiscovered pools too costly to find or is residual oil in proved reservoirs.

The estimate of the amount of oil originally in place is based on: a) exploratory footage already drilled, together with past production and proved reserves; b) the fraction of the total volume of sedimentary rocks that has been explored; and c) the relative attractiveness of the explored rocks to those as yet unexplored.

It is emphasized that these figures are for resources and not for reserves. In order for the oil that constitutes these resources to be promoted to the status of reserves, about 6 billion feet of additional exploratory drilling must be done and the economics of production of the oil must be consistent with demand.