f Drilling Results 2007 – 2009 in the Western Black Sea Targeted on Neogene Deep and Shallow Water Sediments

Prior to 2007 the only drilling in the West Balck sea ( west of Istanbu) were the Karadeniz-1(1970), Igneada-1(1971), and Limankoy 1 and 2 (1999). The resuslts of all of these wells were negative . Despite this, during the period 2006 to 2009 Toreador Turkey embarked upon an exploration campaign in the western Black Sea. Well Karaburun-1(2007) was located adjacent to the Kırklareli area to the Southwest of the previously drilled wells İgneada-1 and Karadeniz-1, The Karaburun-1 well location was defined by seismic surveys conducted during 2007. Karaburun targeted a basement high structure thought to be overlain by Sogucak reefal carbonates. This premise was found to be false and the well finished in volcanics of Yemislicay with no resrvoir potential being encountered. Durusu-1 well was identified by a 1500 km 2D marine seismic survey which was acquired in 2006. Tertiary sediments cover the basement rocks of Istrandja Massif and the Paleozoic istanbul Unit in Thrace Area. Basement rocks are overlain by different stratigraphic units from Early – Middle Eocene to Miocene – Pliocene rock associations.The main and secondary aims of Durusu-1 were to test the hydrocarbon possibilities of the Middle-Late Oligocene aged deltaic Osmancık Sandstones and Late Oligocene-Early Miocene aged Danismen deltaic sandstones. The Osmancık Sandstones together with Ergene and Danismen Sandstones were encountered in Durusu-1 at the expected depths. No DST’s were performed. No core was taken in the well. Drilling was continued down to 2510 m and Durusu-1 exploration well was completed as a dry well on 27.08.2009. Structural and stratigraphic evaluations of 2D seismic data laid the ground for a consistent regional framework. Seismic attributes and sequence stratigraphy indicated that the main Osmancik reservoir interval is part of a large lowstand submarine fan system. Analogies with recent successes in West Africa were noted. The well results are thought to confirm the sedimentological model but unfortunately a source and migration combination were missing.