P- wave and S- wave quality factors (Q P and Q S ) can provide valuable information for identifying the type of ﬂuid in reservoir space. The results calculated by rock physics attenuation model suggest that P- wave and S- wave velocities (V P and V S ) and quality factors vary with frequency, which also induce the reﬂection amplitude variation with frequency. However, the variation of velocities with frequency is small within the seismic frequency range, which can be ignored in the approximation of PP- wave and PSV- wave reﬂection coefﬁcients. Our research begins with the rock physics numerical modeling to verify the reliability of ignoring the inﬂuence of frequency on velocities. The reﬂection coefﬁcient approximate formulas of PP- wave and PSV- wave are derived using scattering function, and these formulas can be applied in the inversion of seismic data for elastic properties (P-wave and S- wave impedances and density) and quality factors. PP- wave and PSV- wave are employed in our approach to estimate quality factors, which can help to improve the accuracy of the inversion. Singular value decomposition (SVD) algorithm is used to solve the inversion problem, and initial models are utilized to constraint the inversion. Synthetic tests show the P- wave and S- wave impedances, density and inverse quality factors can be estimated reasonably even in the case that signal-to-noise ratio (SNR) is 2.
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