Pressure-Depth Graphs

The stress volume created from the seismic reflection mapping (above right) contains the 3D direction and magnitude of each of the three principle, mutually perpendicular stresses SH, Sh and SV. These can be plotted quantitatively with depth and stratigraphy (centre), plus SHD, resulting in a well planning chart for any well (vertical and/or multi directional inclined) displaying the frac gradient (Sh) for low tensile strength rocks, the load (SV) and the compressive stress (SH). The Anderson and PSI extended stress states which combine these stress components, are also plotted.


In many instances, PSI’s 4DGeoStress software can detect and give a good estimation of overpressure (left), also plotted on the PDG.