For many years, interpreters have attempted to further analyze seismic traces by studying their character and by trying to relate waveform variations to stratigraphic changes apparent on well logs, using synthetic seismograms to simulate possible responses. Because this method relies on the comparison of shapes on complex signals, it lacks accuracy and does not go beyond an empirical evaluation. However, direct modeling through interactive well log editing becomes a matter of simple modifications to the sonic and density logs to yield a better correlation between seismic data and acoustic impedance derived from edited logs.

Geologic boundaries can be more precisely interpreted from the resulting logs, and the final model can better match the seismic line with the possibility of varying porosity, inserting new logs, or modifying the depth model and/or variation of lithology to simulate onlap, erosional surfaces, or mixed type of sedimentation. In addition, the interactive package includes such features as wavelet processing and stratigraphic deconvolution to optimize the modeling result. This method of interactive interpretation is illustrated by an example with sandy reservoirs deposited in a deltaic environment.

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