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If light hydrocarbon effect exists in the invaded zone, this must be removed and then replaced by a set of log values representing the un-invaded reservoir condition.
This is the opposite of the stimulation design problem.
The workflow for log reconstruction requires a competent petrophysical analysis for shale volume, porosity, water saturation, and lithology using as little bad log data as possible.
These results are then "reverse engineered" to calculate what the log "should have read" under the modeled conditions we have imposed.
Some calibration data is required from offset wells to do this reliably.
The reconstructed logs are often called synthetic logs, to distinguish them from the original measured data set.
In seismic modeling in light hydrocarbons, the density does not read low enough and the sonic does not read high enough to represent the undisturbed reservoir.
Unless we fix this, reflection coefficients are too small, inversion models of Poisson's Ratio will not be calibrated, and direct hydrocarbon interpretations will be misleading.
The best and easiest modern method for log reconstruction uses the Log Response Equation.
We call this process log editing, or log repair, or log reconstruction, or log modeling .
We can also create missing log curves by the same reconstruction methods.
Track 2 has density correction (dotted curve), neutron (dashed), original density (red), synthetic density (black).
Track 3 shows the synthetic shear, and original and synthetic compressional sonic log curves.
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