Overpressure - Compression

4DGeoStress can estimate overpressure in areas where the excess pore pressure has deformed relatively impermeable shales to the extent that an over-pressured horizon can be distinguished as a thickened unit within a sequence of otherwise thinning units comprising a growing structure.


The normal pore pressure gradient can then be adjusted stepwise (above left) to provide a reasonable estimate of pore pressure and the structure maps are shaded for relative pore pressure, generally increasing with depth. The structure maps are used to shade the area between the blue pore pressure line and the black SH line. Note stress magnitude generally increases with depth and the mud weight window, between the pore pressure and fracture gradient, may narrow.