Calculating Sigmalog pore pressure

The final steps for calculating the Sigmalog pore pressure are performed on the Sigmalog Pore Pressure form (1D Model > Pore Pressure > Sigmalog Pore Pressure). With the Sigmalog Pore Pressure view open as a result of filtering the Corrected Sigmalogs, you can complete the drawing of your lines, calculate and then visualize the resulting non-shale and shale pore pressure logs for QC. After fine-tuning the interpretation, the Merged Sigmalog PP is calculated, which represents the combination of both of the previously calculated curves. For each of the calculated curves, you can also use the boxcar window option, which produces a cleaner, less polluted curve.

To calculate the final Sigmalog pore pressure

1. The Sigmalog Pore Pressure view should be open as a result of the filtering operation. If not, return to the Sigmalog Filtering form and open the view.
2. Prior to performing the interpretation, you can choose to view both full and boxcar logs in the view or select just one to be displayed. With the display option set, click into the tracks to begin your drawing the lines. When the view was opened, use the Editing Tools button to turn on the Custom trend mode, which will allow you to draw the trend lines of your interpretation.
3. When finished with the interpretation, click (Re)Calculate to calculate the Shale Sigmalog PP and Non-Shale Sigmalog PP logs. When calculated, you can click Show to add the two logs, along with their mud weight equivalents and the boxcar filtering, to the Sigmalog Pore Pressure view. Alternatively, you can choose to visualize the logs in the Pore Pressure Prediction view by clicking Show on PP View.
4. After QC of the resulting Shale and Non-Shale Sigmalogs, click (Re)Calculate in the Merge Sigmalog PP section to calculate the final pore pressure as the Merged Sigmalog Pore Pressure.