Seismic exploration of underground formations - with treatment of seismic data to remove or reduce organised noise or other parasitic signals

摘要

In the seismic exploration of a medium by the known technique of sending mechanical waves into the medium, detecting the reflected and/or refracted waves at least one point on the surface and est. the signals which are representative of amplitude. variations with time of the detected waves, the so-called seismic traces, for the formation of a set off such traces, i.e a seismogram, which is processed to give the seismic cross section, the further improvement comprises (a) a seismogram contains a statistically large number of seismic traces, in which the interval between two successive traces corresponds to a ground distance at least equal to the inverse of double the max. frequency of the fixed waves, (b) an analysis of the characteristics of the spatial frequencies of the seismogram is carried out in the treatment of the seismogram for the production of the seismic cross section, (c) the seismogram is thereafter subjected to a filtration to remove from the spatial frequencies these frequencies corresponding to parasitic phenomena, partic. organised noise and determined by the spatial frequency analysis. Enables to organised noise or other undesired parasitic phenomena to be identified, so that they can be filtered out or attenuated and their disadvantageous effects on the analysis of the seismic data eliminated.