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  • Comparative Studies. Non-European Languages/Literatures  (2)
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  • Comparative Studies. Non-European Languages/Literatures  (2)
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  • 1
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2012
    In:  The Journal of the Acoustical Society of America Vol. 131, No. 4_Supplement ( 2012-04-01), p. 3370-3370
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 131, No. 4_Supplement ( 2012-04-01), p. 3370-3370
    Abstract: The flexural wave in fluid-filled borehole excited by dipole sources is dispersive wave. To obtain the phase slowness of dispersive waves, firstly we made several small-scaled model wells, and then measured the acoustical field excited by dipole sources. We researched three kinds of formation, including hard formation (aluminum well models), soft formation (nylon well models) and anisotropy formation (bakelite well models). For hard formation, the flexural mode is the main propagation wave mode in the measured waveforms, and the extracted dispersion curves are well agreed with theory curves. For soft formation, the measured dispersion curves do not well agree with theory curves due to the existence of stoneley wave mode. We drilled seven holes in the anisotropic media with different dip angles. This paper only studied the 7th borehole, whose axis is perpendicular to the symmetry's in this media, which is also called HTI formation model. For the HTI formation model, we observed that the dispersion curve of the slow flexural wave is obviously higher than that of fast flexural wave at the frequency plotted, which is consistent with the theory that the dispersion curves of slow and fast flexural wave arrays for intrinsic anisotropy formation are uncrossed.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2012
    detail.hit.zdb_id: 1461063-2
    Location Call Number Limitation Availability
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  • 2
    Online Resource
    Online Resource
    Acoustical Society of America (ASA) ; 2012
    In:  The Journal of the Acoustical Society of America Vol. 131, No. 4_Supplement ( 2012-04-01), p. 3370-3370
    In: The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 131, No. 4_Supplement ( 2012-04-01), p. 3370-3370
    Abstract: The anisotropy parameters extracted from 4-component dipole waveforms are always affected by dispersion of mode waves, the distribution of stress, the invasion zone and so on. It is impossible to extract the real anisotropy parameters in time domain process. In this paper, we develop a phase spectrum correlation method (PCM) to extract the anisotropic parameters in frequency domain. The PCM searches the real slowness difference of fast and slow flexural waves by comparing the coherence of phase spectra of the fast wave and slow wave. Contrast to the traditional time domain method, this method offers not only the normal shear anisotropy parameters but also an anisotropic map, an anisotropic monitor curve and so on, which can make the interpretation conclusion more reliable. The PCM is verified by both synthesized multi-pole array waveforms and experiment data. The results show that this method is fast and stable for anisotropy analysis.
    Type of Medium: Online Resource
    ISSN: 0001-4966 , 1520-8524
    RVK:
    Language: English
    Publisher: Acoustical Society of America (ASA)
    Publication Date: 2012
    detail.hit.zdb_id: 1461063-2
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
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