ESTIMATION OF DENSITY INHOMOGENEITIES OF GEODYNAMICALLY ACTIVE ENVIRONMENTS BASED ON TIME GRAVITY VARIATIONS IN THE NORTH-EASTERN PART OF THE PACIFIC OCEAN

(Lygin I.V. Tkachenko N.S. )

The article presents the results of the interpretation of the gravitational field variations obtained during the GRACE satellite mission for two geodynamically active regions: over the Alaskan ridge and the San Andreas fault region and the Utah rift.Using spectral analysis of the data the authors show that two regions are confidently localized in the gravitational field, over which significant amplitude variations (up to 20 µgal) are observed. One region spatially corresponds to the boundary of the transition from frontal subduction to oblique collision, the other is the center of the transform fault and the intracontinental rift.Calculations of parameters of deep sources of anomalies of a field of gravity considering sphericity of the Earth are carried out, compared with data of seismometry, global model LITHO 1,0 and information on earthquakes.As a result of the selection, it was determined that the most likely depths of the sources of gravitational field variations under the Alaskan ridge are 150-270 km, and under the San Andreas fault and Utah rift are 50-200 km, the lateral dimensions of the sources for both regions are about 900 by 900 km, the power is 120-150 km. The density change is about 10-3-10-2 kg/m3. The most likely cause of gravitational field anomalies in the Alaskan ridge and the San Andreas fault and the Utah rift is a change in pressure in the asthenosphere. Calculations have shown that for the specified values of density, depth and size obtained by modeling, the pressure decrease in the asthenosphere under the Alaskan ridge is about 0,5 atmospheres, and under the San Andreas fault and the Utah rift is about 0,3 atmospheres. The proposed technique for analyzing the variations obtained from the Grace gravity mission can be successfully applied to other geodynamically active zones.......

More
  • 2020  № 1, pp. 77-83

GEOPHYSICAL ASPECTS OF INTERPRETATION OF REMOTE OBSERVATIONS IN THE TASKS OF GEOLOGICAL AND GEOECOLOGICAL RESEACHS OF GEODYNAMIC PROCESSES

(Akovetsky V.G. )

The article analyzed the current trends in the development of methods for interpreting remote observations in the tasks of geological and geoecological researches of geodynamic processes. The results of a qualitative and quantitative assessment of visual interpretation technologies for structural indicators of fault tectonics in the search for oil and gas fields are presented. Model of two-stage automatic interpretation of remote observations of geological fault are considered taking into account the geophysical aspects of modulation of electromagnetic radiation by objects of the earth’s surface. The implementation of this model in the developed Lineament software module is shown. The results of practical testing of the program module in the problems of qualitative and quantitative interpretation of the observed indicators of geodynamic processes in the studied territories are presented.......

More
  • 2019  № 6, pp. 2-10

DETERMINATION OF POROPERM PROPERTIES OF SALINE TERRIGENOUS ROCKS - RESERVOIR OF ONE OF THE DEPOSITS OF EASTERN SIBERIA BY CORE DATA AND GIS

(Zoloeva G.M. Kulapova M.V. Karamysheva O.I. Navoyan L.U. Nikulina M.U. )

Changing reservoir poroperm properties of terrigenous rocks of the Vendian-lower Cambrian age of the NEPA-botuoba anteclise analyzed for a vast collection of specimens, shows the impact on the petrophysical properties of rocks, their lithological characteristics and secondary processes such as salinization of the pore space with halite. A salinization technique in wells with limited GIS complex is offered.......

More
  • 2019  № 6, pp. 11-16

LITHOLOGY OF OLIGOCENE AND EOCENE-PALEOCENE ROCKS IN EASTERN CAUCASUS REGION

(Sivalneva O.V. Postnikov A.V. Rakhmatullina A.S. Postnikova O.V. Zueva O.A. Idrisova E.K. )

The article describes the results of the lithological investigations and laboratory analysis that would be a base for characterization of the rocks in Oligocene and Eocene-Paleocene deposits. These investigations include sample, thin sections description, SEM, XRD analysis and pyrolysis. The results have demonstrated that anisotropy changes strictly confined to the structure and mineral composition variations. A clay component increasing causes prevalence of the elongate pores, and a carbonate component increasing causes prevalence of the isometric mesh-shape pores as well as the rock susceptibility to fracturing.......

More
  • 2019  № 6, pp. 17-22

UPSCALING IN LITHOFACIAL MODELING OF RESERVOIR ROCKS OF YARAKTINSKY HORIZON

(Izyurova E.S. Izyurov A.D. )

A detailed lithological analysis of the deposits of the yaraktinsky horizon was carried out. Cyclostratigraphic analysis and typification of well sections were performed based on lithological and geophysical data. Depending on the quantitative ratios and the nature of the distribution in the section of cyclites of silt-clay and sand rocks 10 classes (GIS-facies) are allocated. These classes characterize different facies zones and are clearly reflected in GIS curves. For seismofacial modeling, a technique was developed for the allocation of enlarged section types, which represent a set of GIS facies of all cyclites for the yaraktinsky horizon as a whole.......

More
  • 2019  № 6, pp. 23-30
Счетчики