Deep Basin Compartments of Pressurized Water, Petroleum, and Geothermal Fluids

14 Deep Basin Compartments of Pressurized Water, Petroleum, and Geothermal Fluids 

A large number of articles deal with different aspects of abnormal pressures observed in fluid-containing rock compartments (Martinsen, 1994). Recently, there appeared a comprehensive collection of 30 articles dealing with basin compartments and seals (edited by Ortoleva, 1994). The topic is presented by Ortoleva and Wescott (1994)  

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The size of identified pressurized compartments is reported to vary from small-scale structures, 1-10 km across, to mega-scale compartment complexes of hundreds of kilometers across they have been reported from depths of 2000-5000 m and potentiometric heads were mostly between the local (theoretical) hydrostatic head and the local lithostatic head. Multiple compartments are distributed vertically and laterally. The pressurized compartments are regarded to be closed chemical systems as no through-flow occurs in them. 

Bradley and Powley (1994) suggest, The primary cause of either pressure or flow is epirogenic movement, with erosion or deposition, which changes the temperature, stress, and pore pressure in the system, which in turn, affect the diagenesis in the system.  

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