Attenuation can be extremely valuable in characterizing gas sands. In fractured reservoirs, anisotropy can provide additional information about the distribution of fractures. Here, we apply a layer-stripping approach to wide-azimuth P-wave data acquired over a gas reservoir in the Coronation Field, Alberta. The main processing steps involve estimation of traveltimes from the top and bottom of the target layer followed by computation of the interval attenuation using the spectral-ratio method.

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... e vertical attenuation coefficient shows a reasonable correspondence with existing gas-producing well locations and serves as an indicator of gas accumulation in pore spaces. Based on the attenuation information, we infer that the lower half of the survey area has significant gas reserves. In these areas, the estimated azimuthal anisotropy can be used to plan horizontal wells oriented orthogonal to the fracture direction.