Specific features of deep structure and tectonics of the Magadan and West Kamchatka shelves in the Sea of Okhotsk and adjacent area of the Kamchatka Peninsula were verified by geological and geophysical modelling. The investigations aimed at studying the localization pattern of hydrocarbon fields on the northern flank of the Okhotsk oil and gas province are based on results of regional and medium-scale geological surveys and prognostic and prospecting studies, geophysical survey data (gravity anomaly field Δg in the Bouguer reduction with an intermediate layer density 2.67 g/cm3, anomalous magnetic field ΔTа, regional seismic lines and the results of their generalizations), and petrophysical well survey materials. Different algorithms for solving the direct and inverse problems as well as pattern recognition with and without training were used in processing and interpretation of potential geophysical fields. The studies showed that the specific features of deep structure and tectonics of the region are determined by the sequence and nature of manifestation of Mesozoic and Cenozoic orogenic processes at the boundaries of the Eurasian and Okhotsk Sea lithospheric paleoplates. The study of regional shear zones developing along the Okhotsk-Chukotka suture zone and the Okhotsk-West Kamchatka Block demonstrated their vital influence on the morphology of sedimentary basins. Thus, the tectonic activity in the Okhotsk-Chukotka shear zone extending subparallel to the Eurasian coast, led to formation of an extensive network of feather dislocations and basins of two types: large longitudinal shear depressions (sedimentary basins that form due to extersion along strike-slip faults) and shear-pull-apart basins oriented at an angle to the axis of the main shear. Mapping of horst uplifts makes it possible to confirm the position of oil and gas formations prioritized for exploration according to the structural criterion.

The use of the zonal-block model of the earth's crust for the construction of regional tectonic schemes and sections of the earth's crust based on a complex of geological and geophysical data makes it possible to consider the resulting maps and sections as tectonic models. The main elements of such models are blocks with an ancient continental base and interblock zones formed by complexes of island arcs, an accretionary prism, or oceanic crust. The developed geotectonic model of the Sea of Okhotsk region reflects the features of the deep structure, tectonics, and geodynamics. The Cimmerian Novosibirsk-Chukotka, Verkhoyansk-Kolyma, Kolyma-Omolon, and Amur folded regions and the Alpides of the Koryak-Kamchatka and Sakhalin-Sikhote-Alin folded regions are developed along the northern, western, and southern boundaries of the Sea of Okhotsk megablock with a continental crust type. From the east, the megablock is limited by oceanic basins and island arcs.

Advancement in the production of potassium fertilizers is an important strategic task of Russian agricultural industry. Given annually growing production rates, the reserves of discovered potassium-magnesium salt deposits are noticeably decreasing, which creates the need to ensure stable replenishment of the resource base through both the discovery of new deposits and the exploitation of deep-lying production horizons of the deposits that are already under development. In most cases, deposits of potassium-magnesium salts are developed by underground mining. The main problem for any salt deposit is water. Dry salt workings do not require any additional reinforcement and can easily withstand rock pressure, but with an inflow of water they begin to collapse intensively – hence, special attention is paid to mine waterproofing. Determination of spatial location, physical and mechanical properties of the aquifer and water-blocking stratum in the geological section represent an important stage in the exploration of a salt deposit. The results of these studies allow to validate an optimal system of deposit development that will minimize environmental and economic risks. On the territory of Russia, there is a deposit of potassium-magnesium salts with a unique geological structure – its production horizon lies at a considerable depth and is capped by a regional aquifer, which imposes significant limitations on the development process. To estimate parameters of the studied object, we analyzed the data from CDP seismic reflection survey and a suite of methods of radioactive and acoustic well logging, supplemented with high-frequency induction logging isoparametric sounding (VIKIZ) data. As a result of performed analysis, we identified location of the water-bearing stratum, estimated average thickness of the aquifers and possible water-blocking strata. Based on research results, we proposed methods for increasing operational reliability of the main shaft in the designed mine that will minimize the risks of water breakthrough into the mine shaft.