Higgins, R. Eric1, Michal Nemcok2, Dian Vangelov3
(1) Vintage Petroleum, Tulsa, OK
(2) Energy and Geoscience Institute, University of Utah, Salt Lake City, UT
(3) Sofia University "St. Kliment Ohridski", Sofia, Bulgaria
ABSTRACT: Paleogene Sedimentation and Deformation in the Buried Offshore Balkanides – Petroleum System Concepts for a Compressional Fold and Thrust Belt in a Subsiding Oceanic Basin, Deep Water Western Black Sea
Initial studies of the Bourgas Deep-Sea Exploration Block, in the deep water Western Black Sea Basin offshore Bulgaria, reveal the presence of a thick Balkanide foreland sedimentary wedge of Paleogene age. More than 4,000 meters of strata were deposited during the Upper Paleocene to Lower Oligocene, into a basin controlled by a complex interaction of regional compression, subsidence and local extension. These strata were deformed by compressional and gravitational forces to form a number of large, anticlinal structures with potential for hydrocarbon charge and trapping.
Major sequence boundaries, interpreted using newly acquired marine seismic data, as well as seismic data from the early 1990s, have been tied to unconformities and correlative conformities in shallow water offshore wells and onshore geologic exposures.
Preliminary burial histories and basin models developed from seismic sequence stratigraphy, and isopach and seismic facies mapping of these data suggest the potential for hydrocarbon generation and expulsion within the gently deformed Paleogene section, and underlying Mesozoic strata. Sandy Eocene turbidites are potential reservoirs within the Eocene-Oligocene growth folds, while deep water fan and channel systems of Oligocene to Miocene age located along synclinal axes offer potential stratigraphic traps. Neogene extensional collapse, accompanied by subsidence and passive margin style sedimentation, resulted in the burial and preservation of these features under a moderately thick sedimentary wedge, enhancing trap preservation and seal potential
AAPG Search and Discovery Article #90026©2004 AAPG Annual Meeting, Dallas, Texas, April 18-21, 2004.