Структура и эволюция углеводородных систем окраинных морей Северного Ледовитого океана (Восточная Арктика)

Abstract

The article presents the results of studying the structure and evolution of hydrocarbon systems in the marginal seas of the Eastern Arctic — the Chukchi, East Siberian and Laptev Seas. The authors assess the hydrocarbon potential of the studied water areas basing on the results of the basin analysis and numerical modeling. Three promising sedimentary complexes Aptian–Upper Cretaceous, Paleocene–Eocene, and Oligocene–Lower Miocene are predicted in the composition of the sedimentary cover. It is shown that the development of hydrocarbon systems is determined mainly by the rate of sinking of the basins and the thickness of the formed overburden complexes. The main centers of hydrocarbon generation of the Aptian–Upper Cretaceous perspective complex are located in the North Chukchi trough, while those of the Paleocene–Eocene and Oligocene–Lower Miocene complex are located in the Laptev Sea basin. The most likely areas of hydrocarbon accumulation in the reservoirs of the Aptian–Upper Cretaceous complex are the marginal parts of the North Chukchi and East Siberian basins, where deposits are expected at a depth of ~5 km. In the Laptev Sea basin, in addition to the marginal zones, there is a large accumulation area in its central part with deposits predicted at a depth of ≥5 km. In the Paleogene (Paleocene–Eocene) complex, hydrocarbon accumulations are predicted mainly in the central parts of the studied basins and, to a lesser extent, in the near-side parts. The occurrence depths of promising objects vary from 5–6 km in the central parts to 2–3 km in the near-side ones. In the Oligocene-Lower Miocene complex, hydrocarbon accumulations are expected mainly within the Laptev Sea basin at depths of 3–5 km. Significant hydrocarbon potential may be associated with Paleogene clinoform deposits.