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Deriving a Heterogeneous Q Model in Depth Domain Using Seismic Reflection Data and Image Ray: An Example from Daqing Oil
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 80th EAGE Conference and Exhibition 2018, Jun 2018, Volume 2018, p.1 - 5
Abstract
Summary
Anelasticity of the subsurface medium, which is quantified by the quality factor Q, causes dissipation of seismic energy. Because absorption increases with frequency, waveforms are reshaped as they propagate. This absorption and dispersion of the seismic wave requires suitable treatment for imaging the reflectivity of the subsurface with better resolution. However, it is challenging to directly derive an interval Q model in depth domain in the absence of VSP data and cross-well data when we only use the surface reflection seismic data. In this paper, we propose a two-step workflow to derive the background Q model using surface reflection data starting from introducing an effective Q parameter, then we convert the effective Q model to Dix domain. The effective Q model can be estimated using scanning technology at selected CDP locations to avoid the difficulties of determining a reference event and the thin-bed tuning effect in the conventional spectrum ratio or centroid frequency method. This time domain Q model is then converted to depth domain using the image ray. Finally, we validate the heterogeneous Q model using Q-PSDM and obtain an optimal compensation result with better resolution and wider bandwidth.
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