This paper presents the key results concerning oil and gas discovery functions derived from comprehensive computer-supported analyses of the exploration histories of the main producing provinces of the conterminous U.S. To permit meaningful comparison between different geologic regions and/or horizons, the discovery functions are expressed as relationships between exploratory drilling density (in ft/mi³ of sediment) and hydrocarbon content (in bbl discovered/mi³ of sediment). The discovery functions obtained for each basin as a whole are compared to those of the individual depth zones in the basin (the depth zones being defined on the basis of uniform levels of drilling density and/or stratigraphic characteristics). The striking finding of these comp risons is that the discovery functions of the individual (homogeneously explored) depth zones are inherently much more angular or "flat shaped" than those obtained for each basin as a whole. The implications of this finding are discussed in relation to: (a) the theoretical considerations underlying the concept of (negative-exponential-type) discovery functions; and (b) the practical application of discovery functions to the projection of future oil and gas discoveries.

End_of_Article - Last_Page 538------------