James A. Podruski¹, William R. Jamison¹, Brian A. Jones¹, David J. Birnie¹
(1) Alturas Resources Ltd, Calagary, AB

Abstract: Geology and petroleum accumulations in Western Cuba

Three large fields along the north coast of Western Cuba presently produce ~30,000 barrels per day of immature, heavy, degraded crude, from in-place reserves of ~2 billion barrels. Smaller fields from the north coast to the center of Cuba establish the existence of light and medium gravity oils, but no large accumulations have been discovered to date. Reevaluation of the tectonic history and play concepts from analysis of recently acquired geophysical and geologic data suggest that large accumulations of light and medium oil could occur in Western Cuba.

Western Cuba contains four tectonostratigraphic units: Middle Jurassic Rift Sequence clastics and evaporites; Upper Jurassic to Upper Cretaceous Drift Sequence platform to basinal carbonates; Upper Jurassic to Upper Cretaceous ophiolites and arc volcanics that have been obducted over the carbonates in the Upper Cretaceous; and Upper Cretaceous to Recent Successor Basin clastics and carbonates. The Drift Sequence basinal carbonates are source rocks and principal reservoirs in the heavy oil fields. The Successor Basin coarse clastic rocks are secondary reservoir rocks that often contain light or medium oil. Seal rocks are abundant in most of the geologic section. Oil generation and migration probably occurred from the Eocene to Recent. The present structural fabric is predominantly a product of post-Miocene transpression, which locally reactivates existing basement faults and forms domal fault-bounded fold structures that are petroleum traps.

AAPG Search and Discovery Article #90914©2000 AAPG Annual Convention, New Orleans, Louisiana