Hydrocarbon Habitat of the Azov-Kuban Basin, Ukraine and Russian Federation

Klett, Timothy R.¹
(1)U.S. Geological Survey, Denver, CO.

The Azov-Kuban Basin is located along the northeast margin of the Black Sea, encompassing approximately 160,660 km². The basin developed on the continental Scythian block, which accreted onto the Eurasian continent near the end of the Paleozoic. Back-arc extension starting in the Triassic and continuing throughout the Mesozoic formed the basin. The basin margin was stable throughout most of the Mesozoic-Cenozoic, but was converted into a foreland basin during the late Cenozoic.

Major source rocks are mudstones within the middle-upper Eocene and Oligocene-lower Miocene stratigraphic section. Potential source rocks include Lower Cretaceous and Lower to Middle Jurassic mudstones, and possibly Upper Jurassic subsalt black mudstones. Cenozoic source rocks are presently in the oil window; maturation was probably reached in late Miocene to Pliocene when the greatest amount of sediment was deposited. Older source rocks are presently overmature with respect to oil generation having matured in the Late Cretaceous to Paleogene. Most known recoverable crude oil was discovered in Paleogene-Neogene reservoirs and most of the known recoverable natural gas was discovered in Cretaceous reservoirs, although Cenozoic reservoirs also contain significant quantities of natural gas. Seal rocks include Oligocene-Miocene mudstones, intraformational mudstones, and Upper Jurassic evaporites, as well as tar in shallow accumulations. Identified traps are formed by structures associated with mud diapirs, compressional structures (faults and anticlines), basement-related anticlines, and with drapes over basement highs and inverted Triassic rifts. Jurassic and Cretaceous reef facies also provide traps.

The future potential for undiscovered oil and gas accumulations are in structures associated with mud diapirs, deep (>3.5 km) compressional and basement-related structural traps, and stratigraphic traps, which previously have not been fully exploited. Potential stratigraphic traps include Upper Paleogene-Neogene slope and basin gravity-flow deposits, upper Neogene fluvial deposits, and reefs and reef facies in Cretaceous-lower Paleogene and Upper Jurassic subsalt intervals. Offshore areas are less explored than onshore.

AAPG Search and Discovery Article #90135©2011 AAPG International Conference and Exhibition, Milan, Italy, 23-26 October 2011.