Abstract: Stratigraphic Distribution of Undiscovered Oil and Gas Resources in the California Outer Continental Shelf

DUNKEL, CATHERINE, Minerals Management Service, Camarillo, CA

Approximately 10.4 billion barrels of undiscovered oil and 16.6 trillion cubic feet of undiscovered gas (risked mean values) are estimated to exist in the California Outer Continental Shelf. These resources, which can be recovered with conventional extraction techniques, are estimated to exist in petroleum reservoir rocks that range in age from Cretaceous to Pleistocene and whose predominant lithology is either clastic (e.g., sandstone and siltstone) or fractured siliceous (e.g., chert and siliceous shale). The reservoir rocks can be subdivided into three stratigraphic groups on the basis of their age and lithology, and have different petroleum potential. Neogene fractured siliceous rocks have the greatest oil potential, and are estimated to contain more than one half of the undiscovered oil and more than one third of the undiscovered gas. Neogene clastic rocks have the greatest gas potential, and are estimated to contain nearly one half of the undiscovered gas and nearly one third of the undiscovered oil. Paleogene-Cretaceous clastic rocks have appreciably less oil and gas potential than the Neogene rocks; however, the relative proportion of gas to oil in these rocks is generally greater than in the Neogene rocks.

AAPG Search and Discovery Article #90911©2000 AAPG Pacific Section and Western Region Society of Petroleum Engineers, Long Beach, California