The Vysokoye-2 inclined ore body belongs to the Kindikansky section of the Irokindinsky gold ore deposit and is mined underground in mountainous area. Mining operations are conducted in complex geological conditions, which determine changes in the natural and man-made stress behavior of the rock mass. To ensure effective management of rock pressure, a set of studies was performed including a comprehensive study of the geomechanical behavior of the rock mass at the lower levels of the ore body. As part of the research, the fracturing parameters of the rock mass were refined, physical and mechanical tests of rock samples were conducted, and the stability of rock exposures in mine workings was assessed. In situ measurements using the method of the Ural Branch of the Russian Academy of Sciences (at slot-discharge stations in workings of the lower levels) made it possible to identify the distribution patterns of natural stresses in the rock mass. The stress distribution pattern within the Vysokoe‑2 ore body was determined as gravitational‑tectonic. To assess the man-made component of the stress behavior, stress calculations around the workings were performed using the finite element method. This work established permissible stress levels for the rocks, as well as formation patterns of destructive stresses along the workings’ contours. The analysis showed that man-made stresses exceed the permissible values, and therefore, measures for stress relief of the mass are required in the zone of stable rocks. Data from visual inspection of the condition of the workings indicate the presence of static rock pressure. Taking into account the results obtained, recommendations have been developed for the safe mining operations at the Vysokoe‑2 ore body.

The article presents a comparative analysis of modern drilling technologies used in the construction of oil and gas wells in tectonically disturbed carbonate reservoirs of Eastern Siberia. The relevance of the study is due to the high frequency of drilling complications associated with intense fracturing, fault-block structures, and heterogeneity of carbonate formations. The purpose of the study is to analyze the advantages, limitations, and areas of effective application of modern drilling technologies for challenging drilling. The study focuses on three main technological approaches: pneumatic hammer drilling, aerated and foam drilling systems, managed pressure drilling technologies. The methodological basis of the study includes comparative analysis and systematization of published domestic and international scientific and technical sources on drilling in challenging geological and technical conditions. It was established that the efficiency of drilling technologies is determined by the degree of rock fracturing, water cut level, borehole wall stability, and hydrodynamic control conditions. Pneumatic hammer drilling is shown to be the most effective when drilling through hard fractured carbonate formations, while aerated systems are efficient when drilling in severe lost circulation intervals, and managed pressure drilling technologies provide the highest efficiency under conditions requiring precise pressure control. It has been concluded that there is no universal drilling technology suitable for all geological conditions in Eastern Siberia. The most effective approach is the adaptive selection of technological solutions considering geological, hydrodynamic, and geomechanical features of a particular field.

The purpose of the study is to examine the pressing issue of drilling waste treatment – namely, spent drilling muds and drilling cuttings – as well as to analyze the shortcomings of the traditional disposal method in sludge storage ponds, which include low environmental reliability and inefficient use of land resources. The study involves a review and comparative analysis of modern treatment methods: physicochemical neutralization, phase separation, thermal treatment, washing, and curing. Based on the comparison of technological, environmental, and economic criteria, it is substantiated that the curing method using mineral and fast-setting binders is the most preferable. Special attention is paid to formulations based on Portland cement, phosphogypsum, and magnesia cement, the use of which at a dosage of 40% or more makes it possible to form a durable, water‑insoluble matrix that almost completely prevents the migration of petroleum products and heavy metals into the environment. The article also examines current trends in technological development, including the combination of mechanical dewatering, chemical modification, and biological remediation, which provides a synergistic effect and reduces specific costs. The potential for producing man-made soils from recycled cuttings, suitable for construction backfill and reclamation of disturbed lands, is analyzed. It is noted that cured soils allow backfilling of pits and site grading using standard construction equipment, which simplifies the implementation of the technology.

The purpose of the conducted research is to solve a typical problem of engineering and geological zoning of the territory of the city of Neryungri based on the complex of effective values of electrophysical characteristics of coal-bearing sedimentary rocks, with the identification of areas favorable and unfavorable for the construction and operation of engineering structures. A zoning solution was derived from remote inductive sounding data using factor analysis (principal component method). The study resulted in the identification of six factors: decompaction, lithology, lithogenic fracturing, tectonic fracturing, material properties (clay content vs. ice content), and temperature. The former (decompaction and lithology) are referred to the main factors with the total contribution to the variance (energy) of variability of electrophysical characteristics equal to 55.53%. They have a significant impact on the attenuation of the harmonic electromagnetic field at the frequencies of 1.125 and 0.281 MHz, as well as on the electrical resistivity and the real part of the complex dielectric permittivity at the frequency of 0.281 MHz. Fracturing factors with the total contribution of 33.05% affect only the anisotropy characteristics (coefficient and azimuth). Based on the complex mean value calculated after weighted summation of all factors, a layout of the above-mentioned zoning was constructed, in which areas with favorable and unfavorable conditions have been distributed over the area with equal probability. Factor analysis provides a mathematically rigorous and substantively sound supplement and elaboration to engineering-geological survey data regarding the complex, heterogeneous tectonic and exogenous-cryogenic structure, as well as the pronounced spatial variability in the strength and moisture-temperature conditions of frozen, unfrozen, and technogenic-anthropogenic thawed coal-bearing sedimentary rocks in the studied central part of the city of Neryungri.