Joint P and P-SV inversion: Application and testing

Robert W. Vestrum, Robert R. Stewart

Stewart (1990) outlined a method of inverting amplitudes of both P-P reflections and converted P-SV reflections to find changes in P and S-wave velocity. A program has been written to perform an inversion on interpreted P and P-SV seismic data and tests have been performed in order to assess the quality of the lithologic prediction and the range of values that will work in the algorithm.

From the error analysis, we find that the inversion should produce accurate results even for large changes in velocity and relatively long offsets. The inversion produces traces of relative changes in Poisson's ratio and a fluid factor in time. The inverted traces show lithologic or fluid changes in the rock which, in this study, matched the model reasonably well.