A method for estimating apparent displacement vectors from time-lapse seismic images

Reliable estimates of vertical, inline and crossline components of apparent displacements in time-lapse seismic images are difficult to obtain for two reasons. First, features in 3-D seismic images tend to be locally planar, and components of displacement within the planes of such features are poorly resolved. Second, searching directly for peaks in 3-D cross-correlations is less robust, more complicated, and computationally more costly than searching for peaks of 1-D cross-correlations. We estimate all three components of displacement with a process designed to mitigate these two problems. We address the first problem by computing for each image sample a local phase-correlation instead of a local cross-correlation. We address the second problem with a cyclic sequence of searches for peaks of correlations computed for lags constrained to one of the three axes of our images.