Coloured Inversion: Log Calibration
The sonic and density logs are one of the essential datasets used in this coloured inversion package. The impedance log which is the product of velocity log and density log is used to calculate its spectral trend in the frequency domain from which an inversion operator can be derived.
However before being used, the logs have to be calibrated with seismic data. This is because the resolution of the sonic log can be measured in centimetres whereas that of the seismic data is typically between 10 to 50 m. The log data must be averaged for the comparison between logs and seismic to be made.