A sectioned quartz-quartz grain contact revealing a thin clay film (ribbon-like structure). Compaction and shear of these thin clay films has played a key role in controlling compaction of the Groningen gas reservoir to date. Credit: Microstructures were obtained by B.A. Verberne.
Europe's largest gas field, the Groningen field in the Netherlands, is widely known for induced subsidence and seismicity caused by gas pressure depletion and associated compaction of the sandstone reservoir. Whether compaction is elastic or partly inelastic, as implied by recent experiments, is key to forecasting system behavior and seismic hazard.
Interpreting these grains as strain markers, Verberne and colleagues suggest that reservoir compaction involves elastic strain plus inelastic compression of weak clay films within grain contacts.
Idealized volume of reservoir sandstone undergoing vertical compaction with zero horizontal strain, typical of producing gas reservoirs. Note, in this simplification, all grain surfaces are coated with uniform clay films. In a real sandstone reservoir, clay films are discontinuous and locally absent, especially in distal regions of the field (orange--load-supporting quartz framework; blue--sparse feldspar grains; red--clay films). Credit: The conceptual model was developed by B.A. Verberne, S. Hangx, and C. Spiers.
More information:
Berend A. Verberne et al. Drill core from seismically active sandstone gas reservoir yields clues to internal deformation mechanisms, Geology (2020). DOI: 10.1130/G48243.1
Citation:
Gas pressure depletion and seismicity (2021, January 4)
retrieved 16 May 2022
from https://phys.org/news/2021-01-gas-pressure-depletion-seismicity.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.
Let us know if there is a problem with our content
E-mail the story
Gas pressure depletion and seismicity
Your Privacy
This site uses cookies to assist with navigation, analyse your use of our services, collect data for ads personalisation and provide content from third parties.
By using our site, you acknowledge that you have read and understand our Privacy Policy
and Terms of Use.
