Seismic simulations of experimental strata

Experimental strata formed in the new Experimental Earthscape (XES) basin at the St. Anthony Falls Laboratory of the University of Minnesota offer a realistic model for simulating the seismic response of natural strata and thus for advancing understanding of the geologic information that can be extracted from seismic data. A new method is presented here for using digital photos of the experimental strata to generate synthetic seismic data at the length scales and frequencies relevant to oil and gas exploration. In the method, the digital photos are transformed into models of acoustic velocity and bulk density, which are then input into algorithms that generate synthetic seismic data. Three such algorithms are used to demonstrate the approach: a convolutional algorithm, which produces the equivalent of ideal, poststack, time-migrated seismic data; an exploding-reflector algorithm, which produces unmigrated, poststack seismic data; and a full-wave equation algorithm, which we use to produce a synthetic version of prestack, unmigrated, multichannel seismic data. Data generated by the latter two algorithms are processed to compare their information content against both the experimental strata and the ideal seismic data derived from the convolutional algorithm. The qualitative comparison nicely illustrates the filtering of geologic information in seismic data and its further degradation by wave-propagation phenomena, such as diffractions, multiples, and interbed reverberations.

Duke Scholars

Author Lincoln F. Pratson Earth and Climate Sciences