Fundamentals of Stratigraphic Interpretation of Seismic Data
Stratigraphic conclusions from seismic data depend on the data being sufficiently free of noise so that the seismic response is predominantly that of the sediments. Thus good recording and processing are essential. Given a reasonably noise-free response, seismic wavelength limits the detail which can be seen in two dimensions: vertical, or the thickness of Stratigraphic units; and horizontal, or the areal size of features.
Most reflection events seen on a seismic section are composites of reflections from individual interfaces. Calculating the waveform from a sequence of interfaces helps in understanding and interpreting waveform shape. This process is called synthetic seismogram construction where the input information is derived from well logs, and modeling where lateral variation is the principal concern. A comparison between synthetic seismograms and well logs illustrates the resolving power of seismic data and the limitations in trying to invert the process and derive logs from seismic data—thus, the seismic log process. The ease with which Stratigraphic significance can be derived from seismic data also depends on the type of display; those which enhance different aspects of data are helpful in appreciating geologic significance.