Issues of the journals Геофизика 2008 y. issue 6

Seismic Reciprocity Justification for Layered Media. Part 4

(Denisov M.S. )

Several formulations of the seismic reciprocity principle are given. Reciprocical conditions of wave emission and registration are demonstrated. It is concluded that according to one of the formulations the seismic reciprocity principle holds true for both monotype and converted waves in a layered earth. Another formulation, under some conditions, might be incorrect, but holds “approximately”.......

  • 2008  № 6, pp. 3-13

Dominant Mechanism of Seismic Waves Attenuation

(Fayzullin I.S. Faizullin T.I. )

Based on known results of modeling and laboratory measurements and theoretical analysis it is demonstrated that a dominant mechanism of attenuation of elastic seismoacoustic waves in consolidated rocks is owed to scattering by heterogeneities presented by fractures and grain boundaries. Thus it is possible to qualitatively estimate the fractured porosity of limestone and dolomite from measured attenuation of transmitted waves. A related approximation formula is presented.......

  • 2008  № 6, pp. 18-20

Seismic Efficiency of Shock Source in Soft Soils. Experimental Approach

(Polozov S.S. Yushin V.I. )

The measurement of seismic waves energy experiment was carried on. Seismic waves were generated by calibrated sledgehammer ground surface impact. Geophones were buried in the borehole at different depths. The detailed observation grid within investigated medium was realized by moving the seismic source along the land surface. Evaluation of energy was carried on by integration offlux density vector on some cylindrical referential surfaces of different radius. It is founded out that in a closest source zone at the surface with about half wavelength radius observed less than 0,6% of mechanical (kinetic) energy of impact. Decreasing of energy is approximately corresponds with theoretical Rayleigh waves absorption.......

  • 2008  № 6, pp. 21-26

Multi-Wave Well Studies of Polarized-Wave VSP in the Kuzbass Methane-Bearing Coal Thickness

(Zemtsova D.P. Pogosyan A.G. )

This paper discusses integrated approach towards VSPpolarization and CMP data interpretation to produce geological section within in the vicinity of a single well in the Kuzbass area. Joint analysis of these data, along with wide-band acoustic logging, produced reservoir rock elasticity/deformation characteristics in the borehole vicinity, which helped to locate methane accumulations.......

  • 2008  № 6, pp. 27-38