RUDAT, JUHANI, C. J. BANKS, and A. G. ROBINSON, BP Exploration, Uxbridge, Middlesex, England

ABSTRACT: Regional Hydrocarbon Potential of the Black Sea

The Black Sea is a lightly explored enclosed sea, 420,000 sq km in area. Opening of this deep water basin resulted from a period of back-arc extension during the Cretaceous, above the north dipping subducting Tethyan plate, in a region otherwise dominated by compression. The Western Black Sea, underlain by oceanic basement, started to open in mid-Cretaceous time, allowing the subsequent rifting of the Eastern Black Sea. Stratigraphic correlation matches the Moesian platform in Romania with the Western Pontides in Turkey. The Mid Black Sea High which separates the two Black Sea sub-basins, is tentatively correlated with the Shatsky Ridge and the south flank of the Caucasus.

Hydrocarbon source rocks occur in the late Eocene or early Oligocene at the base of the prograding "Maykop" sequence. Airborne Laser Fluorescence surveys recorded fluors indicative of sea-surface hydrocarbon films over the Andrusov Ridge of the mid-Black Sea High.

Geological investigations and acquisition and reprocessing of 23,000 km of seismic data help define the hydrocarbon provinces of the Black Sea. These are: (1) The Southwest shelf in Turkey and Bulgaria with Eocene clastics in diapiric and strike-slip traps. (2) The Romaina/Ukraine shelf with Cretaceous sands and Paleocene limestone reservoirs in tilted fault blocks and inversion anticlines. (3) The Shatsky Ridge, extending some 500 km in front of the Caucasus in Russia and Georgia, with possible Jurassic sandstones and Cretaceous limestones in domal culminations. (4) The Andrusov Ridge, in which extensional tilted fault blocks have been indentified with total closure as much as 3000 sq km. Reservoirs may occur in the pre-rift section or in syn-rift Cretaceous sandstones.

AAPG Search and Discovery Article #90987©1993 AAPG Annual Convention, New Orleans, Louisiana, April 25-28, 1993.