To access the cross-correlation window, select the Cross Correlation tab in the Well-to-Seismic Calibration window (Synthetics Utility).

In the well-to-seismic synthetics utility calibration workflow (Section view), you can work with the 4D correlation window. The correlation module is a tool that supports choosing the parameters in order to obtain the best match between the synthetic seismogram and seismic trace at the well location.

4D Correlation in Well-to-Seismic Calibration

Cross Correlation calculates all possible combinations of time shift and phase rotation pairs. The tool also calculates the cross correlation between the synthetic seismogram and the seismic trace for each of the pairs. The correlation result is displayed on a color map, where the X axis represents the time shift and the Y axis represents the phase shift.

Cross Correlation in 2D Mode – Time Shift Phase are the default selections.

The map color bar is related to the correlation values. The values which are closer to red indicate low correlation; the values closer to blue are highly correlated.

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Author: Kamila Gonçalves, Geophysicist

Best correlation point selection.

The maximum correlation point is indicated in the Tested Location Max Cor. Coef. table.

The Update Current State tool is used to apply the parameters in the synthetic calculation.

When you apply the parameters of the Cross Correlation 4D window, the synthetic seismogram is interactively updated in the Section window.

In the correlation map you can select the best correlation point between time shift and phase shift for use in calculating the synthetic. The map shows three elements:

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Display of the synthetic seismogram after selecting the point of highest correlation in Cross Correlation window.

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When the user clicks anywhere on the map, the synthetic seismogram display is updated simultaneously, but the parameters are not applied. By clicking on the point of highest correlation (white circle), and selecting the Update Current State option, parameters are applied in the synthetic seismogram calculation.

Map correlation elements

Selected by the user.

The purple circle indicates the current status. It represents the "Current State in Wavelet tab".

The white circle indicates a better location, i.e. the point of maximum correlation.