History of deepwater exploration in the Black Sea and an overview of deepwater petroleum play types

Deepwater hydrocarbon exploration drilling only began in the Black Sea less than 20 years ago, primarily because of the economical/technological challenges associated with mobilizing suitable rigs through the Bosporus. However, to date (end 2017), c. 20 deepwater wells have now been drilled, targeting a large variety of plays in this underexplored basin. The deepwater wells drilled to date are categorized by their main play objectives, within either the sag/post-rift or syn-rift basin fill of the Black Sea. The sag/post-rift play types have proven to be more successful, finding either biogenic gas in Miocene to Pliocene reservoirs associated with the Paleo-Danube and Paleo-Dnieper/Dniester or oil in Oligocene deepwater siliciclastic systems. Syn-rift or early post-rift plays, in contrast, assumed mostly shallow water carbonate reservoir targets. Only one well targeted pre-rift stratigraphy. Most of the exploration failures to date are directly related to the lack of reservoir at the targeted stratigraphic levels. However, the recent discoveries have underlined the presence of at least two active and effective petroleum systems that cover large parts of the deepwater Black Sea Basin.