The paper is aimed at the prediction of oil and gas occurrence of the Upper Permian, Lower Triassic and Lower Jurassic deposits in the Vilyui hemisineclise. The basin modeling research implies the Upper Paleozoic and Mesozoic petroleum system model of the Vilyui hemisineclise. The initial generation time at the bottom of the Permian source rock is 270 Ma. The most intense generation of hydrocarbons is found to be in the late Permian and early Triassic. The generation power of the Permian source rock is 800 trillion m(3). The hydrocarbon losses is up to 90% in consequence of unfavorable seal properties of the Lower Triassic and Lower Jurassic clay formations. All the potential hydrocarbon traps of the Vilyui hemisyneclise are considered to be formed during the Cretaceous stage of development. There is therefore an appropriate environment for the hydrocarbon accumulation to be in progress. The interpretation of geological and geophysical data identifies the areal extent prediction of sand reservoirs and overlying clay interlayers of high quality in the Upper Permian and Lower Triassic seals. The goal of a comprehensive approach to the sedimentary basin research is to divide the territory into oil and gas zones of various prospects in relation to the factors controlling hydrocarbon deposits.

A characteristic of the Upper Paleozoic, Lower Triassic and Jurassic oil and gas bearing complexes (OGC) of the Vilyui hemisineclise was done.After refinement of the geological model of reservoirs of the Upper Peleosoic-Mosozoic complexes, a quantitative assessment of hydrocarbon resources was carried out.

Условия формирования залежей углеводородов в мезозойских и верхнепалеозойских отложениях Вилюйской гемисинеклизы1 Институт нефтегазовой геологии и геофизики им.А. А. Трофимука СО РАН, г.

On the territory of the Vilyui hemisyneclise, the presence of hydrocarbon deposits in the Lower Triassic deposits is determined by the presence and distribution of sandy seams of shallow-water genesis - reservoirs for hydrocarbons, as well as marine clay deposits - tires capable of retaining hydrocarbons. Based on the interpretation of the materials of geophysical studies of wells and seismic exploration, a forecast was made for the distribution of sandy layers of the Lower Triassic deposits of the Vilyui hemisineclise containing gaseous hydrocarbons, as well as clay packs of a local and regional nature, which serve as seals for each of the productive layers.

In the work, a comprehensive interpretation of seismic materials and drilling data was carried out, sets of structural maps and isopach maps of seismogeological complexes were constructed, which served as the basis for structural-tectonic analysis and study of the history of the formation of the Srednetyungsky uplift, which controls gas deposits in the Upper Permian and Lower Triassic deposits. It is concluded that in the relief of the base of the Triassic, the Middle Tyung uplift was formed in the Cretaceous as a result of an increase in tectonic activity in the territory of the entire Vilyui hemisyneclise.

НОВЕЙШИЙ ПРОГНОЗ И АКТУАЛИЗАЦИЯ ОСВОЕНИЯ НЕФТЕГАЗОВЫХ ОБЪЕКТОВ ВИЛЮЙСКОЙ СИНЕКЛИЗЫ

The work is devoted to the petroleum system modeling in the Vilyui hemisyneclise located in the Republic of Sakha (Yakutia). The study identifies the maturity and generation history of organic matter in the Permian coal-bearing rock, compaction history of the seals and areas of prospective hydrocarbon deposits of the Lower Jurassic, Lower Triassic, and Upper Permian rocks.

One-dimensional models of petroleum systems are widely used to reconstruct the process of the source rocks thermal evolution. The paper is aimed at the modeling in a well section of the Andylakh gas condensate field - the Republic of Sakha (Yakutia). Tectonically, it is confined to the central part of the Loglor structure located in the Vilyuy hemisyneclise. The modeling identifies the burial history of the sedimentary section, history of vitrinite reflectance, temperature, and transformation ratio of the source rock kerogen during the Paleozoic, Mesozoic and Cenozoic time, quantitive evaluation of generation power and remaining potential of the source rocks. The Kuonam organic matter is assumed to be overmature. The Permian source rock is found to be in the oil and gas windows at the present time. The Permian source rock is of significant petroleum generation capability. Maximum heat flow and temperature values, rapid subsidence of the sedimentary section and change in organic matter maturity in the Late Permian and Early Triassic imply trap rocks in the sedimentary cover.

We present the interpretation of 2D seismic data in the Vilyui hemisyneclise located in the Republic of Sakha (Yakutia). The model identifies structural and tectonic features and tectonic development history of the Mesozoic deposits in the Vilyui hemisyneclise. Structure contour maps for the reflecting horizons of the Mesozoic are qualitatively the same. Traced faults attenuate at various stratigraphic levels. The structures of the hemisyneclise are known to be formed during the Cretaceous stage of development.

The paper is aimed at the basin and petroleum systems modeling in the Vilyui hemisyneclise located in the Republic of Sakha (Yakutia). The Vilyui hemisyneclise is known to be the deepest depression of the Siberian Platform. The research identifies maturity and temperature history of the Permian source rock in the Mesozoic and Cenozoic, kitchen areas, accumulation balance of hydrocarbons in reservoirs, trapping of gas and gas-condensate deposits in the Upper Permian, Lower Triassic, and Lower Jurassic rocks. Funding: The reported study was funded by RFBR, project number 19-35-90039.