Powered by OpenAIRE graph
Found an issue? Give us feedback
addClaim

The estimation method of anisotropy coefficient of shear wave velocities

The estimation method of anisotropy coefficient of shear wave velocities

Abstract

© SGEM2018. Cross-dipole acoustic logging traditionally uses to study the anisotropy of the formation acoustic properties. The method is based on comparing the velocities of fast and slow shear waves and calculating the anisotropy coefficient. In the anisotropic formation, the flexural wave is splitting into two modes. The amplitude of cross-components XY and YX will be non-zero and significant in the anisotropic zones of the formation. There are several approaches to assessing the presence of anisotropy in a formation. As a criterion can be used: the difference in the energy of the cross-components (minimum and maximum), the difference in arrival times of fast and slow waves, and the value of the anisotropy coefficient as well. The purpose of the research was the development of the processing method for the anisotropy coefficient estimating using the four-component waveform data. Alford rotation was used to calculating the projecting of source waveform data to the needed angle and get fast and slow waveforms. The base of the offering method is the calculation of the time shift magnitude between each separate channel of waveforms. The increase in the amount of displacement with increasing channel number was obtained. This indicates that the fast and slow waves have different speeds. The slope of the hodograph, constructed from the magnitude of the shift, makes it possible to estimate indirectly the difference between the velocities of the two waves, i.e. identify zones with anisotropy. The results obtained are in good agreement with the traditional method of calculating the anisotropy coefficient using slowness (or velocities) of fast and slow shear waves. This technique can be used for anisotropy zones presence estimation and does not require knowledge of the velocity values.

Keywords

Sonic logging, Anisotropy coefficient, Fast and slow shear waves

  • BIP!
    Impact byBIP!
    selected citations
    These citations are derived from selected sources.
    This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
    0
    popularity
    This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.
    Average
    influence
    This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
    Average
    impulse
    This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.
    Average
Powered by OpenAIRE graph
Found an issue? Give us feedback
selected citations
These citations are derived from selected sources.
This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
BIP!Citations provided by BIP!
popularity
This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.
BIP!Popularity provided by BIP!
influence
This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
BIP!Influence provided by BIP!
impulse
This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.
BIP!Impulse provided by BIP!
0
Average
Average
Average
Upload OA version
Are you the author of this publication? Upload your Open Access version to Zenodo!
It’s fast and easy, just two clicks!