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Seismic Tectono-Stratigraphy Modeling of Deep Marine Oligo-Miocene Siliciclastic Reservoirs in Levant-Cyprus Basin Frontier Zone


After the recent commercial gas fields discoveries in Miocene sandstones in the southern part of the frontier zone of Levant- Cyprus Basin, greatest interests have concerned this area. The Neogene plays are essentially represented by Miocene sandstones turbidites as it was discovered firstly in Aphrodite 1 welll, with gross mean reserve of 16 TCF of biogenic gas, succeeded by Leviathan 1, Dalit 1 and Tamar 1 well discoveries. The source rocks are assured by Jurassic, Cretaceous and Tertiary hemipelagic rich organic marls. The basin tectonic structuring and new seismic sequence stratigraphy study of Oligo-Miocene silicolastic deposits horizons based on the analysis and interpretations of new regional selected E-W and N-S 2D seismic grid acquired in 2008 using new PGS geostreamer technique and calibrated to wells data and outcrops had highlighted the basin configuration and sequence deposits infill nature and distribution of Oligocene and Miocene silicoclastic reservoirs. Geotectonic setting of the basin is marked by NE-SW and N-S deep seated sub vertical strike slip normal and reverse inherited faults around the shelf borders and by NW-SE faults in the centre. This basin dynamics allow to classify the levant basin as a deep water mobile substrate basin characterized by the existence of Deep-water fold belts fed by large rivers. Oligo-Miocene horizons are organized in 3 second order sequences composed by 5 Oligocene, 4 Lower Miocene, and 5 to 7 Middle-Upper Miocene third order seismic sequences. Oligocene and Miocene early lowstand horizons of deposits present downlap prograding sigmoid, oblique and mounded slope fans system tracts and basin floor mounds and large turbidites sheets and lobes, overlain and cutted by late lowstand incised channels, canyons and levees. The size of channels and canyons of Oligocene ranges from 3 to 5, 10 and 15 kilometers width with an average thickness between 100 and 350 meters, sometimes reaching 1500 meters whereas size of channels and canyons of Miocene ranges from 3 to 10 kilometers width and 100 to 300 meters infill thickness. Locally, canyons are bigger and stacked as multistory extending from Oligocene to Lower Miocene. Reconstructed paleogeographic reservoir fair maps highlight three new exploration domains around the Levant basin of sandstone/shale system tracts deposits related to the upper slope, lower slope and basin floor.