Paleogeographic Conditions for the Evolution of Sedimentary Cover in the Lapev Sea Based on Seismic Facies Analysis

The Laptev Sea is an area of active exploration for hydrocarbons; however, estimations of its hydrocarbon potential vary significantly, both in terms of total hydrocarbon quantities and their phase composition. This variability is due to the absence of a unified geological framework and, consequently, the use of different analogous basins in calculations. Based on a comprehensive interpretation of geological and geophysical data, as well as seismic facies analysis, a reliable geological model was created. Paleogeographic conditions for the formation of major sedimentary cover complexes were reconstructed, including the Aptian-Upper Cretaceous, Paleocene-Eocene, Oligocene, and Miocene-Quaternary periods. It was shown that, within the modern shelf of the Laptev Sea, a marine basin existed since the second half of the Cretaceous, the boundaries of which are determined based on outcrop data from adjacent islands and onshore, wells, and seismic patterns. The main factors controlling the formation of the sedimentary cover and the change of paleogeographic conditions along the modern Laptev Sea continental margin were global tectonic events, including the opening of the Makarov-Podvodnikov Basin, rifting, and post-rift subsidence in the Eurasian Basin.