Coupling of diagenetic alterations and mechanical properties of Lower Permian siliciclastic sandstones: a pilot study

Abstract

Initial detrital composition and authigenic alterations during diagenesis of three sandstone types are related to their mechanical properties. Sandstones were prepared for geotechnical standard tests [density, uniaxial compressive strength (UCS), Young’s modulus (E), strain at failure (ε)] and thin sections for petrographic analyses (point counting). UCS ranges from 3 to 62 MPa and positively correlates with density (1.75–2.35 g/cm3) and E (0.3–12.7 GPa). Optical porosity is controlling these mechanical parameters and was linked to diagenetic alterations. Diagenetic alterations affecting porosity reduction are the abundance of clay minerals, and the intensity of mechanical and chemical compaction. The latter is controlled by clay mineral coatings on contacts between detrital grains, and the occurrence of authigenic quartz and dolomite. Horizontal contact lengths of grains normalized to their respective particle diameter (effective contact ratio, ECR) and porosity are identified as a control on the mechanical properties UCS and E, reflected by the rock strength index SR. The results of this pilot study suggest that SR is able to predict UCS and E based on petrographic information obtained from the studied samples. These results enhance the understanding of the coupling between mineralogy and geomechanics and highlight the impact of diagenesis on geomechanical behavior.

Effects of reservoir mechanical properties on induced seismicity during subsurface hydrogen storage

“…North Sea Chalk is the overburden rock for the Britannia and Goldeneye Fields.The properties used in table 3 are derived from the ‘Overall Range’ column herein.References from which each property was extracted were: true0Eres—Monsees et al . [68], Camm et al . [69], Shell [70]; true0Kres—Hillier [71], Camm et al .…”

“…References from which each property was extracted were: true0Eres—Monsees et al . [68], Camm et al . [69], Shell [70]; true0Kres—Hillier [71], Camm et al .…”

“…The properties used in table 3 are derived from the 'Overall Range' column herein. References from which each property was extracted were: E res -Monsees et al[68], Camm et al[69], Shell[70];K res -Hillier[71], Camm et al[69], Shell[72]; ρ b, res -Hillier[71], Camm et al[69], Shell[73]; ν res -Ji et al[74], Dvorkin and Nur[75], Shell[70];…”

Petrographic and geotechnical evaluation of Ogwashi-Asaba ferruginised sandstone, Niger Delta, as aggregates for construction

“…Rakshit et al (2021) while investigating the influence of micromechanical properties of sandstones of Western Indo-Burmese Ranges, Northeast India, opined their strength reduction to be a result of the presence of angular and semi-angular spherical grains. Similarly, Monsees et al (2021) while investigating the relationship between diagenetic alteration and mechanical properties of Permian Siliciclastic sandstones suggested optical porosity which was linked to diagenetic alteration as a significant factor influencing its mechanical properties. Wang et al (2019) who observed the failure modes for three types of sandstones noticed the destruction of the sandstone with the highest strength before the mudstone interface.…”