Issues of the journals Геофизика 2014 y. issue 3

Energy filtering geophysical fields

(Nikitin A.A. )

Practical possibilities of optimum energy filtration are considerd for potential and wave fields. The identy of energy filter and principle component analisys is estabished Multiattridute energy filterung algorithm for integrated data processing is suggested This algorithm takes into account correlation befween fields and fheir attributes on survey area or the plane of tine sections.

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  • 2014  № 3, pp. 2-13

Seismic waves changes due to the gas presence in porous rocks

(Nikolaevskii V.N. )

Because of deformation type differences in gas-oil reservoirs under pores saturation (> 90%) by liquids, only fast wave Р, is propagating but in gas layers this wave attenuates and only slow wave P is observed. This fact explains a seismic shadow beneath of gas horizons for waves Р,. Positive results of low frequency seismic waves are explained by changes of P-waves types. Dominant frequencies of passive seismic and active (vibrate) action corresponds to different resonant wavelengths. The equation of own layer oscillations is derived that contains the intervals of negative damping for dominant frequencies. According observations and recommended equations random disturbances are strengthening the useful signals at dominant frequencies. Waves P of dominant frequency at active action are penetrating into the shadow of wave Р and give more detailed picture of rock saturation with oil. They are useful for AVO methods. Oil layer full with gas bubbles and compressed by depth rock pressure is oscillating as a whole body under external seismic action.......

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  • 2014  № 3, pp. 14-20

The rules for reservoir differentiation using longitudinal and shear wave velocities

(Sidorov V.K. Tarantin M.V. )

We present a new method for revealing zones where rocks do fulfill the known average time equation using acoustic log-data. Such rocks are shale-less fluid-saturated porous ones with solid matrix; they have a distinct correlation between porosity factor and permeability. The rule for separation is closeness (coincidences) in such zones of profiles of porosity parameters being calculated by longitudinal and shear waves velocities using given equations. Exceeding the porosity factor calculated from longitudinal wave velocities by that from shear wave velocities reflects a shale rate of a zone.......

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  • 2014  № 3, pp. 21-24

Progress in theory and interpretation of pulsed neutron logging

(Poliachenko A.L. Poliachenko L.B. )

Presented are results of research and solutions of a wide range of problems being urgent for the practice of integral Pulsed Neutron Logging (PNL) mostly of the theoretical, computing, methodical and interpretation character. These results and solutions are related to applying the Pulsed Neutron Logging method in oil-and-gas and uranium borehole geophysics and could be considered as the up-to-date stage in the advancement of the PNL method.......

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  • 2014  № 3, pp. 32-40
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