Deconvolution: Problems and Approaches in Reflection Seismics

Abstract

In homogeneous and isotropic media, the shape of a seismic wavelet remains unchanged as it propagates. There is only a decrease in amplitude, due to geometric spreading of the wavefront. At interfaces between layers, part of the energy of the signal is reflected and the rest is transmitted. If the seismic source were a pulse, a seismogram of sharp primary and multiple reflections (in this book called an impulse seismogram of the medium) would be recorded for such a homogeneous and isotropic, layered medium. In reality the situation is considerably more complicated:

• • The source signal is band-limited and not a delta function.

• • Near-surface layers produce reverberations that can mask later arrivals of reflections.

• • The source signal changes its shape due to absorption as it propagates.

• • Geophone and recording equipment modify the signal.

• • Noise components are superimposed on the reflected wavefield.