Abstract

The simulation of offset vertical seismic profiles (VSP) has been effectively accomplished using the discrete frequency-wavenumber method. Surface multiples and peg-leg multiples can be readily incorporated into the calculations. Mode converted arrivals can also be generated with relative ease. The technique is practical in the sense that no rays need to be specified.

A VSP modelling capability not only aids interpretation of VSP field data, but also provides the seismic interpreter with a powerful means to check the effectiveness of the various processing steps. In addition, it can also be used to obtain an optimum field configuration before a VSP survey is carried out. Examples are given for several models with relevance to seismic exploration.

With an appropriate modification of the technique, synthetic VSP seismograms for dipping layers, faulted beds, and deviated-hole VSP can be simulated. The examples are kept simple to aid the tutorial aspect of the paper. With a large number of layers, the waveforms become complex and structural interpretation is difficult.