About This Item
Share This Item
Abstract
Chapter from: M
61: Basin Compartments and Seals
Edited by
Peter J. Ortoleva Author:
John S. Bradley and David E. Powley Methodology and Concepts
Published 1994 as
part of Memoir 61
Copyright © 1994 The American Association of Petroleum
Geologists. All Rights Reserved. |
![](images/indent.JPG) |
---|
![](images/indent.JPG) |
---|
![](images/indent.JPG) |
Chapter 1
*
Pressure Compartments
in Sedimentary Basins: A ReviewJohn S. Bradley
Consultant
Tulsa, Oklahoma, U.S.A.
David E. Powley
Consultant
Tulsa, Oklahoma, U.S.A.
*
ABSTRACT
Pressure compartments are found in sedimentary
basins throughout the world. They are defined primarily by hydraulic potentials
calculated from pressure measurements but may be indicated by differing
brine and hydrocarbon chemistries; by mineralogic differences; by electrical
resistivity, sonic velocity, and density of the shales; and by mud weight
requirements and drilling rate changes.
Pressure compartments are characterized
by an effective seal , in three dimensions, that prevents pressure equilibration
to normal hydrostatic pressure. A pressure seal , as opposed to a capillary
seal , restricts flow of both hydrocarbon and brine and is formed where
the pore throats become effectively closed, i.e., the permeability approaches
zero. A leaking pressure seal , called a "rate seal ," occurs when the pressure
difference caused by subsidence-sedimentation or uplift-erosion or other
pressure source is greater than the seal pressure leakage. When the internal
fluid pressure in the compartment exceeds the fracture pressure of the
seal , the seal will fracture and fluids will escape from the compartment.
The fracture and resealing may occur repeatedly.
Multiple pressure seal origins must be
invoked to explain their geometric and stratigraphic occurrence. Certainly
some pressure seals appear to be stratigraphically controlled with perhaps
more or less diagenetic enhancement. Some seals, particularly those that
cross stratigraphy, appear to be entirely diagenetic. The lateral seals,
which appear to be subvertical to vertical, are possibly due to faulting
and fracturing or to lateral facies changes. An extensive investigation
of seal origin, recognition, and duration is being undertaken by a consortium
of universities under the sponsorship of the Gas Research Institute.
|
---|
Pay-Per-View Purchase Options
The article is available through a document delivery service. Explain these Purchase Options.
Watermarked PDF Document: $14 |
Watermarked Document A Watermarked Document is branded with the name of the original licensed customer to discourage unauthorized users from sharing the document outside the user's organization. The PDF is no longer restricted to one machine, but can be circulated to others in the same company or department. A Watermarked Document also can be printed for hard copy distribution internally but is not authorized for outside distribution nor posting on the internet. Users will not be able to cut-and-paste text or images from one document to another.
|
Open PDF Document: $24 |
Open Document An Open Document is a fully functional PDF that can be circulated (a digital copy or hard-copy printed documents) outside the purchasing organization. Purchase of an Open Document does NOT constitute license for republication in any form, nor does it allow web posting without prior written permission from AAPG/Datapages ([email protected]).
|
GIS Map Publishing Program