1.
n. [Geology]
The
pressure within the Earth, or
formation pressure. The common
oilfield usage, however, is to indicate
anomalous subsurface
pore pressure that is higher or lower than the normal, predicted hydrostatic pressure for a given depth, or the pressure exerted per unit area by a column of
fresh water from sea level to a given depth. Abnormally low pore pressure might occur in areas where fluids have been drained, such as a depleted
hydrocarbon reservoir. Abnormally high pore pressure might occur in areas where burial of water-filled sediments by an
impermeable sediment such as
clay was so rapid that fluids could not escape and the pore pressure increased with deeper burial.