60-47 Geomechanical Investigation of Caprock Systems in the Michigan Basin: A Scratch Test Study of the Glenwood and St. Peter Formations

Session: 2YC and 4YCU Geoscience Student Research Poster Showcase

Poster Booth No.: 47

Presenting Author:

Cailey Treece

Authors:

Treece, Cailey¹, Zakharova, Natalia², Kim, Boyoung³, Burns, Moira⁴, Scott, Ashley⁵, Haagsma, Autumn⁶, Conner, Amber⁷, Kaczmarek, Stephen E.⁸, Harrison, William⁹

Abstract:

Carbon capture, utilization, and storage (CCUS) continues to gain traction as a cornerstone strategy for reducing atmospheric CO₂ concentrations. In the Michigan Basin, effective implementation depends on understanding the integrity and behavior of reservoir-caprock systems under subsurface injection conditions. This study focuses on two key Cambrian-Ordovician formations: the Glenwood Formation, evaluated as a confining unit, and the St. Peter Sandstone, targeted as a potential reservoir.

To overcome limitations posed by sparse legacy datasets and conventional petrophysical approaches, this project utilizes the scratch test: a continuous mechanical profiling technique capable of measuring unconfined compressive strength and elastic properties with high resolution. By applying this method to core samples from both formations, the study aims at a more comprehensive geomechanical characterization than traditional methods normally allow and without compromising the structural integrity of the core.

Preliminary results of the Glenwood Formation display considerable heterogeneity in strength and stiffness, with localized zones of reduced integrity that may pose challenges to long-term containment. Variations in grain fabric, mineralogical composition, and diagenetic alteration contribute to this mechanical variability, stressing the need for site-specific evaluations of seal performance. Meanwhile, the St. Peter Sandstone demonstrates more uniform geomechanical properties, although spatial heterogeneity should be further evaluated by comparison to other locations.

Through integration of scratch test data, mineralogical analyses, and refined stratigraphic correlations, this research enhances our understanding of spatial variability and controls on mechanical properties of caprock formations. The findings provide a critical foundation for future CCUS site selection within the Michigan Basin, supporting broader efforts to achieve net-zero emissions through secure geological storage of CO₂.

This project is funded by the U.S. Department of Energy (DOE) under DE-FE0032368 and 2025 Undergraduate Summer Program for Arts and Research at Central Michigan University.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-9934

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