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Impact of Petrographical Attributes on Geomechanics in a Sandstone Reservoir for CO2 Storage - Ketzin, Germany
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 75th EAGE Conference & Exhibition incorporating SPE EUROPEC 2013, Jun 2013, cp-348-00181
- ISBN: 978-90-73834-48-4
Abstract
Reservoir geomechanics is essential to assess reliable candidate reservoirs for CO2 storage. Geomechanical models are necessary to understands zones of stress localization and failure due to injection related pressure increase and require rock mechanical parameterization. Sandstone aquifers of fluvial origin, however, exhibit a very heterogeneous setting of geomechanical parameters. To enhance the understanding of the anisotropic distribution of geomechanical parameters in heterogeneous sandstone, petrographical attributes are correlated with geomechanical tests for uniaxial compressive strength, tensile strength and friction angle. Tests were undertaken on cores from different wells drilled at the CO2 pilot site Ketzin in the North German Basin. Petrographical attributes are determined on thin sections. Our results indicate a strong correlation between grain size and cement type on geomechanical parameters. Anhydritically cemented segments of the Upper Triassic sandstone reservoir represent the strongest parts of the aquifer rock with highest E-modules. High differential stresses would be necessary to induce failure of the reservoir rock top segments whereas siltstone succession within the reservoir centre are close to failure under estimated in situ stress conditions. The delineation of geomechanical facies as provided by our study help to enhance sedimentologically based geomechanical models of sandstone reservoirs for CO2 storage.