ABSTRACT: Sea Level Controls on Carbonate Facies Associated with Mesozoic and Cenozoic Hydrocarbon Fields

Christopher G. St. C. Kendall, Bruce Bowen, Abdulrahman Alsharhan, David Stoudt

Abundant subsurface data for the Mesozoic and Cenozoic sections of the Gulf Coast of the United States and the Middle East makes it possible to track the relationship of shelf carbonates and evaporites with minor clastics to eustatic sea level. Since sedimentary stratigraphy for both regions was driven by gentle tectonic subsidence punctuated by eustatic sea level variations, the major hydrocarbon fields from these areas can be classified in terms of sea level behavior at the time of the deposition of the reservoir section. With the exception of chalks, most of these carbonate hydrocarbon fields can be related to highstand system tracts and include (1) keep-up plays with sheet-like geometry formed when carbonate accumulation matched sea level rise, aggrading to form shoal ng-upward cycles during sea level highstands; (2) give-up plays in which carbonate accumulation was unable to match sea level rise and catch-up plays in which carbonate accumulation initially was unable to keep pace with the sea level rise, but then aggraded to sea level forming lense-like geometry on drowned shelves downslope from carbonate margins during and following rapid sea level rises; and (3) plays with the prograded discontinuous clinoform geometry of the platform margin, formed during stillstands by carbonate accumulation that not only kept-up with the sea level rise but accumulated in a seaward direction.

Source rocks for these carbonate reservoirs often formed during rapid sea level rises whereas the reservoir seals are usually shales, dense limestones and/or evaporites.

AAPG Search and Discovery Article #91003©1990 AAPG Annual Convention, San Francisco, California, June 3-6, 1990