Page 60 - The Petroleum System From Source to Trap

3. Petroleum Systems of the World Involving Upper Jurassic Source Rocks 53

Figure 3.2. North America Upper Jurassic deposition areas, petroleum systems, and Lower-Middle Jurassic source facies
(westem Laurasia sector). (See Figure 3.1 for explanation of symbols.)

petroleum (BOE); and (3) the system's estimated ultimate UPPER JURASSIC SOURCE ROCKS
conventionally recoverable BOE. These estimates have
been accomplished with published data and are subject Present-Day Geography
to more error in frontier basins. However, the calcula­
tions for the petroleum system recovery efficiency are About 80% of the BOE generated from Upper Jurassic
within a magnitude believed to provide the accuracy source rocks comes from sedimentary basins or
needed for the general conclusions of this study. provinces located on or in the interior of continents,
Subsequent to the preparation of this paper, two other while 20% of the BOE comes from basins or provinces
areas of Upper Jurassic source rocks have been docu­ located along continental coastal areas (Table 3.3).
mented: the French Aquitaine basin (Espitalie and Interior basins or provinces contain an estimated 70% of
Drouet, 1992) and the Algoa-Gamtoos basin of South the Upper Jurassic mature source rock area and 56% of
Africa (Malan, 1993). the volume. Continental coastal areas contain 30% of the