Changes

==Local pressure compartments==

==Local pressure compartments==

[[file:formation-fluid-pressure-and-its-application_fig5-27.png|400px|thumb|{{figure number|3}}See text for explanation.]]

[[file:formation-fluid-pressure-and-its-application_fig5-27.png|400px|thumb|{{figure number|3}}Porous bioherm completely encased in shale.]]

The fluids in a [[Porosity#Carbonate pore systems|porous]] [[bioherm]] completely encased in shale (as shown in [[:file:formation-fluid-pressure-and-its-application_fig5-27.png|Figure 3]]) are virtually isolated from the nearby fluid systems outside the bioherm. The bioherm, then, is a pressure compartment that may or may not be abnormally pressured. Other geological features that may form local pressure compartments are fault blocks, sand lenses, and sand wedges developed in [[growth fault]]s.

The fluids in a [[Porosity#Carbonate pore systems|porous]] [[bioherm]] completely encased in shale (as shown in [[:file:formation-fluid-pressure-and-its-application_fig5-27.png|Figure 3]]) are virtually isolated from the nearby fluid systems outside the bioherm. The bioherm, then, is a pressure compartment that may or may not be abnormally pressured. Other geological features that may form local pressure compartments are fault blocks, sand lenses, and sand wedges developed in [[growth fault]]s.