| The Biot mechanism is treated in a macroscopic framework and the squirt flow is examined at the individual pore level. Biot's theory has been a successful tool for interpreting experimental data, and applied in sciences as diverse as geophysics. However there are many examples of real earth materials for which Biot'theory does not seem to explain the dispersion and attenuation very well. As a matter of fact, Dvorkin and Nur(1993) have shown that the squirt flow mechanism results in much higher and realistic attenuation in saturated rocks than that predicted by the Biot mechanism. The united Biot and squirt flow mechanism model is presented by Dvorkin and Nur(1993). From then on, the BISQ model has been drawing much attenuation. The thesis studies the acoustic field excited by monopole source,dipole source and quadrupole source in fluid-filled borehole surrounded by the transversely isotropic two-phase formation about Biot's theory model and the BISQ model. Not only dispersion and attenuation of mode waves and the full-waveforms are particularly analyzed, but also the propagation mechanism of the critical refracted P-wave and S-wave waves corresponding to the multipole source branch cut integrations are studied. Measurements of dispersion and attenuation of elastic waves in porous media can gain acoustic parameters about porous media, and the studying has been widely cared by physics,mechanics and geophysics et.al, while inverse of permeability has always been cared by well logging field. The thesis studies detailedly the influence of the vertical and the horizontal permeability on the dispersing and attenuation of mode waves. In the two theory model, comparing with the vertical permeability, attenuation of mode waves are more sensitive to the horizontal permeability; attenuation of mode waves are more sensitive to the horizontal permeability and the vertical permeability in BISQ model than in Biot model; the changes of the horizontal permeability and the vertical permeability have some influences on dispersion of stonely wave, but have almost no influence on the dispersion of pseudo-Rayleigh wave,flexural wave and screw wave. Therefore, wo can inverse permeability (specially the horizontal permeability). We study that the influence of the squirt flow mechanism on the dispersion and the attenuation of mode waves. In the transversely isotropic formation, the attenuation's values of stonely wave and flexural wave are bigger in BISQ model than in Biot model, the squirt flow mechanism has the influence on the dispersion of stonely wave while having almost no influence on the dispersion of flexural wave; In the isotropic formation, the attenuation's values of mode waves are bigger in BISQ model than in Biot model. By the full-waveforms and exciting curve of the critical refracted P-wave and S-wave, we can see that the squirt flow mechanism has no influence on the velocity and the attenuation of shear wave but has the influence on the propagation mechanism of P-wave in the isotropic formation. While the squirt flow mechanism has the influence on the propagation mechanism of P-wave and S-wave in the transversely isotropic formation. From full-waveforms we can see that mode wave's amplitude value become smaller including the squirt flow mechanism. We can find that the first resonance frequency values of P-wave and S-wave excited by monopole source are adjacent by P-wave spectrum and S-wave spectrum. The first resonance apexes of P-wave and S-wave excited by dipole source and quadrupole source separate gradually. When the isotropic formation becomes the transversely isotropic formation, the resonance apexes and the resonance frequency values change. Comparing with the isotropic formation, the resonance apexes of P wave move to low frequency and the resonance apexes of S-wave move to high frequency. The thesis studies also the influence of permeability on P-wave spectrum and S-wave spectrum. When the horizontal permeability becomes bigger, the exciting...
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