Estimating broad trend of acoustic impedance profile from observed seismic reflection data using first principles only

Estimation of broad features from the low-frequency part of acoustic impedance from conventional reflection data is an essential yet challenging step, which currently is performed by assuming either an initial impedance model or statistical restrictions on such a model. We have formulated a set of linear equations to do this from first principles that are then solved for an unknown reflection co-efficient using singular value decomposition (SVD) approach with time sampled seismic trace as the input data. The present work demonstrates the effectiveness of reconstructing a broad and smooth impedance profile from first principles and also illustrates the method’s success with real data, while determining in one go the unknown scale factor linking the true and the relative seismic amplitudes, and the smallest singular value to be retained in the solution from only the knowledge of the average value of the acoustic impedance over the depth range in question. This approximate impedance profile can serve as a reliable initial input for more refined inversion or geologic interpretation.

 

Citation

 

Animesh Mandal and Santi Kumar Ghosh; Journal of Geophysics and Engineering (2020) 17, 475–483; doi:10.1093/jge/gxaa006