ABSTRACT

Oils of the Gulf of Mexico slope typically show higher sulfur contents, higher metal contents, and lower API gravities than do oils of the Gulf shelf. These properties result in increased costs of production, transportation, and refining, thereby diminishing their value. In contrast to shelf oils, many of which are derived from lower Tertiary shale source rocks, the sources of slope oils are thought to be of Mesozoic age. Because deeply buried source rocks have not been encountered during drilling on the slope, we focus on detailed geochemical characterization of the slope oils to infer their origin. Biomarkers suggest variable clasticstarved source facies containing marine kerogen, such as marls and carbonates. Higher sulfur contents and lower API gravities are thought to correlate with increasing carbonate content of the source facies and milder thermal maturity histories. Oils having carbonate sources in the Upper Jurassic Smackover and Lower Cretaceous Sunniland trends show some similarities but are not strong analogs.

End_of_Record - Last_Page 770-------