A Study of the Seismic Signatures of Sedimentation Models Using Synthetic Seismograms*

Abstract

In modern exploration for hydrocarbons there is a great emphasis on the location of stratigraphic traps and estimation of lithologic information like sand‐shale ratios from seismic data. In order to investigate the possibilities of success in this endeavour we have studied the synthetic seismograms for wave form and spectral characteristic for four basic sedimentation models: (I) interbedded sand‐shale model representing the sediments of generally fluviatile origin, (2) interbedded coal‐shale model representing deltaic deposits, (3) sedimentary models representing transgression and regression of shore lines, and (4) a basal sand model. The results have shown that for the first two models a change in the sand‐shale or coal‐shale ratio results in a characteristically different seismogram. The nature of the seismogram, however, is also strongly dependent on how the sand‐shale or coal shale layers are arranged to ultimately give the same number of total layers, thus implying the same coal‐shale or sand‐shale ratios. The transgression, regression, and basal sand models also produce characteristically different seismic signatures. The spectra of these seismograms show attendant characteristic changes. However, it seems that in the case of real data which are disturbed by noise and the effects of overlying layers these characteristic features may not always be distinguishable.

Characterization of complex fluvio–deltaic deposits in Northeast China using multi-modal machine learning fusion

“…Before interpreting seismic data, the data must be sufficiently free of noise. This is to ensure that the seismic response mainly reflects the sedimentary strata in the area of interest 40 . Although a good signal-to-noise ratio (SNR) depends heavily on careful acquisition and processing of seismic data, remnants of noise can mask the subsurface characteristics of the processed sections.…”

Spectral properties of the earth’s contribution to seismic resolution

“…These zero-or low-amplitude notches between the amplitude bands indicate that even a two-interface sequence such as a thin layer will inherently be missing certain frequencies. Geologic sequences with more than two interfaces will have more complex spectral signatures that must be examined case-by-case (e.g., Berzon, 1969;Khattri and Gir, 1976;Khattri et al, 1979;Bilgeri and Carlini, 1981;Walden and Kosken, 1985;Gochioco, 1992).…”

Seismic Modeling of Complex Geological Structures

“…Model building techniques developed significantly over the past decades. Khattri & Gir (1976) used a series of lithological elements through a cyclic succession (for example sand and shale) to create different 1D seismic models. The seismic response of such models have been predicted using ray theory approach.…”