EARTH CRUST STUDIES USING GEOPHYSICAL METHODS

(Tarantin M.V. Kostitsyn V.I. Prostolupov G.V. Chadaev M.S. Gershanok V.A. )

Earth's crust of the Fennoscandian Shield and the northeastern part of the East European platform (Russian and Pechora plates) was subject to the detailed study. Presented results are obtained in the Vector system, and include depth gravity maps and sections, as well as the Moho map of Tibet. Examples of forecasting the structural inhomogeneities of the lower crust are based on the elevation changes of the Moho boundary. Extended positive anomalies reflect location of the gold-bearing provinces of the Fennoscandian Shield.......

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  • 2020  № 5, pp. 79-83

COMPREHENSIVE USE OF LOGGING AND GEOLOGICAL-TECHNOLOGICAL INFORMATION IN GEONAVIGATION

(Shumilov A.V. Shao CaiRui Yuan Ye Zhai XingYu Zhang QingXun Zhang FuMing )

Geosteering with logging while drilling (LWD) represents the state of the art in directional drilling technology. However, the current China LWD dataset is dominated by non-azimuth gamma ray and resistivity measurements, leading to uncertainty in geosteering results. Consequently, the full use of LWD, logging and drilling data to evaluate and interpret drilled formations in real time becomes a beneficial means to overcome the disadvantages of using LWD data alone. This study presents the technology for integrated 3D and 2D visualization of LWD data, logging and drilling, and presents a method for their integrated use for reservoir assessment, reservoir modeling and geosteering. Practice has shown that the most complete and complex information based on the reservoir model and visualization methods is the key to improving the accuracy of reservoir modeling, optimizing the wellbore trajectory and increasing the drilling success rate. Thanks to active research into geosteering capabilities, reservoir assessment methods and technologies, appropriate software was developed and successfully applied in a number of oil fields, which ultimately increased the competitiveness of geosteering technologies of Chinese companies, balancing the technological level in comparison with multinational companies and breaking the monopoly on the formation of service prices.......

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  • 2020  № 5, pp. 84-92

ACCOUNTING THE EFFECT OF TERRAIN RELIEF DURING AEROMAGNETIC SURVEYING WITHIN LARGE MAGMATIC PROVINCES

(Dolgal A.S. Muravina O.M. Krivolutskaya N.A. Ponomarenko I.A. )

The problem of taking into account the influence of a sharply dissected relief of the earth’s surface during aeromagnetic surveys carried out in areas of intense magmatism is considered. The factors that have a significant effect on the accuracy of magnetic field reduction are listed. An original method is presented for assessing the influence of the upper part of the geological section, composed of intensely magnetized rocks, on the results of field observations. The method uses the decomposition of digital data on the magnetic field and elevations into empirical mode functions, followed by applying to the obtained components of the method of group accounting of arguments. The results of the reduction of medium-scale aeromagnetic survey in Eastern Siberia are presented.......

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  • 2020  № 4, pp. 2-8

BOREHOLE MAGNETOMETRY IN THE STUDY OF THE URAL SUPERDEEP BOREHOLE

(Igolkina G.V. )

Magnetometry studies of the superdeep well of the Ural SG-4 allowed us to obtain data on magnetic fields, magnetization and magnetic susceptibility of rocks at great depths in natural occurrence. The study of the magnetic properties of tuffs and tuffites revealed the relationship of magnetic parameters with their structural and textural features. Studies have made it possible to determine the spatial position of the magnetic bodies illuminated by the well, to calculate their elements of occurrence. It is established that the use of well magnetometry increases the reliability of structural constructions according to geological data and makes possible deep structural forecast.......

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  • 2020  № 4, pp. 9-15

CAPABILITIES OFFERED BY VSP WHEN PROCESSING AND INTERPRETING ONSHORE 2D/3D SEISMIC DATA

(Lensky V.A. Irkabaev D.R. Zhuzhel A.S. )

The fact that VSP is playing an increasingly bigger role during land seismic data processing and interpretation can be explained by the need to reach a new level of data processing and interpretation with more precise and detailed geological results. This level cannot be attained without accounting for certain aspects of wavefield imaging, evaluating its relationship with a geological medium and monitoring how this relationship changes during the processing stage. The methodology of such studies is only now beginning to be developed and capabilities offered by VSP are still not fully addressed by geophysicists working with seismic data. This paper looks at the most pertinent problems that can be solved through VSP to improve the quality of both processing and interpretation of land seismic data. A number of problems requires the elaboration of specialized techniques and practices of borehole observations involving different modifications, including VSP 2D and VSP 3D. The efficiency of utilising VSP data increases with a greater density of studied wells drilled within a seismic survey area. By analysing data areally, we can establish a relationship between variations in velocity characteristics as well as properties of reflections and variations in depositional environments, more thoroughly control the quality of land seismic data processing and substantiate the best possible criteria for structural and dynamic interpretation, which may vary across different parts of the survey area.......

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  • 2020  № 4, pp. 16-24
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