About This Item
- Full TextFull Text(subscription required)
- Pay-Per-View PurchasePay-Per-View
Purchase Options Explain
Share This Item
Evaluation of the aquathermal mechanism proposed by Barker indicates that this process cannot produce geopressures in clays or sediments with even negligible permeabilities. It is suggested that, because the amount of fluid expansion is very small with temperature increase, typical hydraulic conductivities of clay rocks can accommodate the removal of this excess fluid in the time span available; thus it would appear that expansion of waters cannot contribute to the geopressure generating process.
Lithologies of effectively zero permeabilities, however, may provide adequate sealing of contained pore fluids so that pressures increase with increasing temperature. The subsequent rupturing of the matrix, as pore pressures reach overburden pressures (particularly rapidly at shallow depths), produces fractures which may later provide routes for hydrocarbon migration.
As a pressure transition zone cannot exist due to the necessary "isolation" of pore fluids, current geopressure evaluation techniques are limited in their application such that only flowline temperature interpretation may indicate subsequent penetration of an aquathermally generated geopressure. If a transition zone does exist above a geopressured interval, then some process other than aquathermal pressuring must have been instrumental.
Pay-Per-View Purchase Options
The article is available through a document delivery service. Explain these Purchase Options.
|Protected Document: $10|
|Internal PDF Document: $14|
|Open PDF Document: $24|
Members of AAPG receive access to the full AAPG Bulletin Archives as part of their membership. For more information, contact the AAPG Membership Department at [email protected].