Deep-Water Traction Current in Upper Carboniferous Stratigraphic Succession of Moscow Stage, Southeastern Pre-Caspian Basin

Deep-water currents are geographically widespread and represent important tight-oil and -gas reservoirs. However, identifying deep-water traction current deposits is challenging work. The main objectives of this research were to identify a new type of reservoir deposited in deep-water traction currents. Based on high-quality 3D seismic data and drilling data (logging data and lithology), the sedimentary characteristics of the MKT Formation of the upper Carboniferous Moscow Stage, southeastern Pre-Caspian Basin, were determined. The MKT Formation of the upper Carboniferous Moscow Stage is mainly composed of mudstone and some thin-bedded siltstone. This formation contains a series of “reversal foresets” dipping west (early paleo–high provenance during the depositional stage). Based on the seismic data and drilling logging data, lithology, paleo-geographic position, seismic facies, and form and scale, deep-water traction current deposits were identified in the M block. The discovery of deep-water traction current deposits in the M block not only provides a precious example for research on Paleozoic deep-water traction current deposits, and enriches our knowledge of basin sedimentary types, but also proves that the M block had complex fluid features and unveils a new domain for petroleum exploration in the basin.