Abstract：Normal and tangential weaknesses are sensitive to fluid type in fractured reservoirs. In order to make the best use of AVOZ information included in seismic data, we discuss normal and tangential weaknesses direct inversion method based on azimuthal elastic inversion, which can be used to guide fluid identification in fractured reservoirs. Firstly, using the relationship among anisotropic rock physics parameters, we build an azimuthal elastic impedance equation based on the anisotropic weaknesses. Then, aimed at the instability of extracted anisotropic parameters, we put forward a stable normal and tangential weaknesses extracting method, which can improve the inversion accuracy of normal and tangential weaknesses. Finally, fracture weaknesses parameters obtained from the inversion are used for fluid identification in fractured reservoirs. Model and real data tests indicate that the proposed method can efficiently identify fractured gas reservoirs.
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