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| Titel |
Grain-scale deformation in granular materials: time-lapse XCT-imaging of a deforming reservoir sandstone |
| VerfasserIn |
Suzanne Hangx, Benoit Cordonnier, Ronald Pijnenburg, Francois Renard, Christopher Spiers |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250148796
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| Publikation (Nr.) |
 EGU/EGU2017-13086.pdf |
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| Zusammenfassung |
| Relating macroscopic deformation of granular media to grain-scale processes, such as grain
fracturing, has been a focus of many studies. Understanding these processes is key for
predicting surface subsidence and induced seismicity caused by hydrocarbon depletion, the
hydraulic fracturing response of geothermal reservoirs, and post-seismic crustal deformation.
With the development of state-of-the-art techniques, such as time-lapse X-ray tomography
imaging during triaxial deformation, new avenues to investigate the operating mechanisms
have opened up.
As a first step to understanding grain-scale deformation processes, we performed a
deformation experiment on highly porous sandstone, obtained from a depleting gas reservoir,
using a novel small-scale triaxial deformation apparatus coupled to high-resolution 4D X-ray
tomography, available at the European Synchrotron Radiation Facility (ESRF, Grenoble) and
Université Grenoble Alpes. This state-of-the-art apparatus allows for 3D time-lapse imaging
of samples, while deforming at pressure, temperature and fluid flow conditions relevant for
geological reservoirs.
We performed our experiment at relevant in-situ reservoir conditions (T = 100˚ C, 10
MPa pore pressure, 40 MPa effective confining pressure). Axial stress was increased
step-wise until failure occurred, while continuously imaging deformation. This enables us to
monitor progressive grain failure, and strain localisation, during deformation in real-time.
Though the vast amount of data obtained from even a single test poses challenges for data
analysis, this presentation will address the first results obtained from this experiment. |
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