About This Item
Share This Item
Abstract
 |
|---|
|
 |
|---|
|
|---|
|
Importance
of Fabric and Composition on the
Stress Sensitivity of Permeability
in Some Coals, Northern Sydney Basin, Australia: Relevance to
Coalbed Methane Exploitation1R. M. Bustin2 |
|---|
|
|---|
|
 |
|---|
|
|---|
|
| ABSTRACT Fabric and composition of a series of Upper
Permian high-volatile to low-volatile bituminous coals of the Sydney basin
have a marked effect on stress sensitivity of permeability, and thus on
the reservoir characteristics of the coal. The coals vary in composition
from end members of predominantly bright-banded coal comprised mainly of
the microlithotype vitrite and the maceral vitrinite, to dull coal composed
of significant amounts of ash, inertinite group macerals, and the microlithotype
inertite. The brighter coals are more extensively fractured with one or,
more commonly, two or three regularly spaced fracture sets (cleats) spaced
at 5-20 µm. Fusinite and semifusinite, common macerals in the dull
coals, are characterized by phyteral porosity (mainly cell lumens) and
fabric- selective intergranular porosity.
The permeability of tested samples varies
significantly with composition and effective stress. The fabric of the
samples is the most important factor in determining permeability and stress
sensitivity of permeability. Coals with the highest permeability are those
with at least one well-developed, throughgoing fracture set; these samples
generally include abundant vitrite bands. The lowest permeability samples
are nonbanded, with an attrital fabric and significant authigenic mineralization.
At
©Copyright
1997. The American Association of Petroleum Geologists. All rights reserved. 1Manuscript
received April 1, 1996; revised manuscript received December 4, 1996; final
acceptance June 16, 1997.
2Department
of Earth and Ocean Sciences, University of British Columbia, Vancouver,
BC V6T 1Z4, Canada.
This
study was financially supported by a grant from CSIRO (Syndal) and by The
Earth Resources Foundation, University of Sydney. Samples and some data
were provided by Pacific Power Ltd., Sydney. I thank Paul Gamson, formerly
of CSIRO, for overseeing the permeability analyses and facilitating some
of the study. I thank K. Wright of the Earth Resources Foundation, University
of Sydney; J. Enever of CSIRO; J. C. Close of Meridian Oil; and Chris Clarkson
of University of British Columbia for their comments on an earlier draft
of this paper. Reviewers Andrew Scott, Roger Taylor, and W. Ayers are thanked
for their thoughtful comments. |
|
|---|
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]).
|
AAPG Member?
Please login with your Member username and password.
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].
GIS Map Publishing Program
