The Impact of Recent Data on the Interpretation of the Geologic Evolution and Petroleum System of the Eastern Black Sea Basin, Offshore Georgia

Ryan J. Wilson, Neil Mountford, Paul Maguire, and Richard Hedley
Anadarko Algeria Corporation, Uxbridge, United Kingdom

The genesis and sediment-fill history of the Eastern Black Sea Basin, offshore Georgia has been largely understudied with little new data being acquired since the Soviet Era. However, recent data acquired demonstrate the existence of a Tertiary petroleum system.
The Oligo-Miocene Maykop Formation is a widespread source rock that extends from Romania to Turkmenistan. It has been identified as the source of the hydrocarbons in the giant fields of the South Caspian and the accumulations in both the western and eastern onshore basins in Georgia. In addition, oils collected and analyzed from active seeps offshore Georgia, directly above mapped structural culminations, confirms the presence of a generative Maykop in the Eastern Black Sea Basin.
Offshore Georgia can be subdivided into three tectonic provinces, one of which is characterised by high-amplitude anticlines that strike in a southwest-northeast direction as a result of shortening from the Middle Miocene to present day. These fold and thrust anticlines range from classic box folds to overturned folds, with a common decollment within the Maykop.
The primary reservoir sands are believed to be of Middle Miocene age, and based on 3D seismic data, the sandstones were deposited in deepwater channel-levee systems that originated from the north. Late Miocene to present day depositional systems have a south-easterly provenance of volcanic/lithic origins.
In 2005, the first deepwater well in the Eastern Black Sea Basin was drilled offshore Turkey but did not penetrate the northerly-sourced reservoir system. Consequently, the offshore Georgia petroleum system, with billion barrel opportunities, remains untested.

AAPG Search and Discovery Article #90072 © 2007 AAPG and AAPG European Region Conference, Athens, Greece