Middle devonian-lower frasnian natural hydrocarbon reservoirs of the Pechora Sea shelf and Timan-Pechora oil and gas province adjacent area

The research is based on the three-layer natural hydrocarbon reservoirs theory, which allocates 3 layers in a natural reservoir – the genuine seal, the productive part and the intermediate layer situated between them - the false seal. The Middle Ordovician-Lower Frasnian terrigenous complex variable in thickness, composition and stratigraphic completeness sub-regional natural reservoir was identified in the northern part of the Timan-Pechora oil and gas province adjacent to the Pechora Sea. It includes several zonal and local natural reservoirs (Middle Ordovician-Lower Devonian, Middle Ordovician-Eiffelian, Zhivetian-Lower Frasnian and others). The distribution areas of these natural reservoirs were extrapolated to the Pechora Sea offshore. The areas with the highest prospects of oil and gas potential of the Pechora Sea offshore were delineated, basing on the Timan-Pechora oil and gas potential analysis. These are the northwest extensions into the Pechora Sea of the Denisov trough, the Kolva megaswell, as well as the Varandei-Adzva structural zone and the Karotaiha depression. Keywords: natural reservoir; genuine seal; false seal; field; pool; hydrocarbons.

Technogenic transformation of the underground hydrosphere of Kazan. Lower Kazanian aquifer complex

Relevance. By the beginning of the XXI century, the growth of cities, population concentration and the revival of industrial production led to an intense technogenic pressure on the underground hydrosphere. In ecological and hydrogeological studies, it becomes necessary to conduct monitoring observations of groundwater based on GIS technologies. Purpose of the work: study of the hydrogeochemical characteristics of underground waters of the aquiferous lower Kazanian carbonate-terrigenous complex to provide Kazan with high-quality drinking water from protected underground sources. Research methodology. Hydrochemical data from geological reports and archival materials for the period from 1960 years to 2019 years were used. Methods of mathematical statistics (basic, cluster and factor analyzes) made it possible to differentiate into natural and man-made components. Geographic information modeling using the “ArcGisMap” package showed the spatial variability of the main components in the waters of the Neogene complex at the turn of the 20th and 21st centuries. Conclusion. The hydrochemical parameters of the aquiferous lower Kazanian complex are assessed as favorable, since practically all the main components do not exceed the MPC values for drinking water.

VOLCANICS IN THE UDYL’ SEGMENT OF THE KISELEVKA-MANOMA ACCRETIONARY TERRANE (SIKHOTE-ALIN): PETROGEOCHEMISTRY, FORMATION CONDITIONS, AND TECTONIC POSITION

New petrogeochemical data were used to determine conditions for the formation of volcanics and their tectonic position in the area of Lake Udyl’. These rocks were correlated with similar rocks in the region. Volcanics of two genetic types were identified in the area of Lake Udyl’: 1) intraplate oceanic volcanics as part of the accretionary volcanic-siliceous complex (Tithonian-Valanginian-Hauterivian-Barremian) similar to accretionary complexes in other segments of the Kiselevka-Manoma Terrane, and 2) suprasubduction-zone volcanics as part of the island-arc volcanogenic-terrigenous complex (Valanginian-Hauterivian-Aptian-Albian-Cenomanian). A conclusion about the tectonic superposition of complexes of different genesis in the Udyl’ segment is based on synthesis of the new geological and petrogeochemical data, as well as geochronological and paleomagnetic data from previous studies.

STRUCTURAL CHARACTERISTICS OF VENDIAN-CAMBRIAN SEDIMENTS WITHIN THE NORTHTUNGUSKA OGR USING SEISMIC 2D DATA IN CONNECTION WITH PETROLEUM POTENTIAL

Complex interpretation of seismic and parametric drilling data is performed. The data for interpretation are obtained within the conjunction zone of the Kureyka syncline and the Anabar anteclise. As a result of complex interpretation the structural maps on the bottom of Vendian and the top of the Kuonamka formation are constructed. Map of the Vendian terrigenous complex was constructed. High prospects of oil and gas potential of the lower-middle Cambrian sediments are shown. Based on the analysis of logging data, core description and detailed correlation of time sections, the litho-acoustic models were compiled for two profiles crossing the barrier-reef system, and two-dimensional synthetic time sections were calculated. Obtained results confirm the correctness of the ideas about the internal structure of the Vendian-Cambrian complexes.