Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Web of Science (4) Citing Articles via Google Scholar Google Scholar Articles by Cartwright, J. Articles by Aplin, A. Search for Related Content GeoRef GeoRef Citation

Seal bypass systems

¹ 3DLab, School of Earth, Ocean and Planetary Sciences, Cardiff University, Cardiff CF10 3YE, United Kingdom; joe{at}ocean.cf.ac.uk
² 3DLab, School of Earth, Ocean and Planetary Sciences, Cardiff University, Cardiff CF10 3YE, United Kingdom; present address: Department of Geology and Petroleum Geology, University of Aberdeen, Aberdeen AB24 3UE, United Kingdom; m.huuse{at}abdn.ac.uk
³ NRG, School of Civil Engineering and Geosciences, University of Newcastle, Newcastle upon Tyne NE1 7RU, United Kingdom; a.c.aplin{at}ncl.ac.uk

Joe Cartwright received his B.A. degree and his D.Phil. in geology from Oxford University. He is a research professor of geophysics and director of the 3DLab at Cardiff University. His research interests focus on three-dimensional seismic interpretation in basin analysis, with special emphasis on seal integrity analysis, the genesis of polygonal faults, the emplacement of sandstone and igneous intrusions, and silica diagenesis.

Mads Huuse received his Ph.D. from the University of Aarhus in 1999. In 1999–2005, he was a postdoctoral researcher, first at the University of Aarhus, then at the University of Aberdeen, working on injected sands, and finally, at Cardiff University, working on cap rocks. Currently, he is lecturer of geophysics at the University of Aberdeen. His special interest is in the seismic imaging of fluid-flow features, glacial deposits, and cool-water carbonates.

Andrew Aplin received his Ph.D. from Imperial College in 1983. He was a Royal Society European Fellow at Centre de Recherches Pétrographiques et Géochimiques Nancy from 1983 to 1984 and worked at BP as a research geochemist from 1984 to 1990. Since 1990, he has worked at the University of Newcastle, where he is currently professor of petroleum geoscience. His main research interests are in the physical and fluid-flow properties of fine-grained sediments.

We present an interpretational framework for the analysis of a diverse set of geological structures that breach sealing sequences and allow fluids to flow vertically or subvertically across the seal. In so doing, they act as seal bypass systems (SBS). We define SBS as seismically resolvable geological features embedded within sealing sequences that promote cross-stratal fluid migration and allow fluids to bypass the pore network. If such bypass systems exist within a given seal sequence, then predictions of sealing capacity based exclusively on the flow properties (capillary entry pressure and hydraulic conductivity) of the bulk rock can potentially be negated by the capacity of the bypass system to breach the grain and pore network. We present a range of examples of SBS affecting contrasting types of sealing sequences using three-dimensional (3-D) seismic data. These examples show direct evidence of highly focused vertical or subvertical fluid flow from subsurface reservoirs up through the seal sequence, with leakage internally at higher levels or to the surface as seeps.

We classify SBS into three main groups based on seismic interpretational criteria: (1) fault related, (2) intrusion related, and (3) pipe related. We show how each group exhibits different modes of behavior with different scaling relationships between flux and dimensions and different short- and long-term impacts on seal behavior.