About This Item
Share This Item
Abstract
|
---|
|
|
|
|
|
Klusman,
R. W., and M. A. Saeed, 1996, Comparison of light hydrocarbon microseepage
mechanisms, in D. Schumacher and M. A. Abrams, eds., Hydrocarbon
migration and its near-surface expression: AAPG Memoir 66, p. 157-168. |
|
---|
|
---|
|
|
|
|
|
|
|
|
Chapter
12
|
|
---|
|
---|
|
|
|
Comparison
of Light Hydrocarbon Microseepage Mechanisms |
|
---|
|
---|
|
|
|
|
Ronald W.
Klusman
Department of Chemistry
and Geochemistry
Colorado School of Mines
Golden, Colorado, U.S.A.
|
|
Mahyoub A.
Saeed
Faculty of Science
University of Sana'a
Sana'a, Republic of Yemen |
|
|
---|
|
---|
|
|
Abstract
Surface geochemistry
applied to hydrocarbon exploration has gained little acceptance due to
the lack of a satisfactory mechanism for vertical migration that is plausible
and explains all observations. Acceptance of surface geochemistry is also
hampered by a widely held belief that reservoirs do not leak. A satisfactory
mechanism must apply in a wide variety of geologic environments and must
be verified by laboratory and field observations. Three mechanisms are
proposed for vertical migration of light hydrocarbons: diffusion, transport
in aqueous solution, and buoyancy of microbubbles.
Diffusion fails to explain
the rapid disappearance of surface anomalies after production from a reservoir
begins. Diffusion is sufficiently rapid to dissipate gas reservoirs quickly
in the geologic sense. As a vertical migration mechanism, it also cannot
account for the resolution observed in surface anomalies. Diffusion as
a mechanism for primary migration of hydrocarbons from source rocks and
as a transport mechanism in the near-surface unsaturated zone have been
demonstrated. Solubilities of light hydrocarbons in water are low at ambient
temperatures, but increase dramatically with increasing temperatures at
depth in basins. Transport with water, either in solution or as a separate
hydrocarbon phase, is important in secondary migration. Computer modeling
of the process using finite-difference techniques fails to explain the
observed resolution and rapid disappearance of surface anomalies.
We favor the vertical migration
mechanism of displacing water by ascending gas bubbles, that is, the "buoyancy
of microbubbles." Computer modeling of this mechanism does explain surface
observations. The close correspondence of surface anomalies with surface
projections of a reservoir and the rapidly disappearing surface anomalies
after the start of production are predicted by this model. |
---|
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