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DOE OSTI · 2478670

Developing Methods to Assess Changes in Mechanical Properties of Shale Modified by Engineered Mineral Precipitation

Bedey, K.·Cunningham, A. B.·Phillips, A. J.·Kirkland, C. M.·Willett, M. R.·Dobeck, L.·Eldring, J.·Crandall, D.·Rutqvist, J.
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Abstract

Fractures in subsurface shale formations serve multiple purposes, for example, in the recovery of resources in hydraulic fracturing or as potential harmful leakage passages through caprocks that may contribute undesired fluids to the atmosphere or functional groundwater aquifers. A proposed method to seal or influence fracture properties is Ureolysis-Induced Calcium Carbonate Precipitation (UICP), a bio-mineralization technology driven by the enzymatic hydrolysis of urea, resulting in the formation of calcium carbonate. The resulting calcium carbonate can bridge the gaps in fractured shale and reduce fluid flow through fractures. This study represents the first step toward determining the influence of UICP treatment on shale material and its subsequent mechanical strength properties. The goal of this preliminary work is twofold: first, we aim to identify a method to test tensile strength along a core axis and second, we seek to assess the effect of temperature on the tensile strength of intact, unfractured shale cores (2.54 cm (1 in) diameter, 5.08 cm (2 in) long for comparison with future fractured and UICP-treated cores. A modified Brazilian indirect tensile strength test successfully measured splitting tensile strength of shale cores from Eagle Ford and Wolfcamp formations at room temperature and 60°C.

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clastic rockcomplex reservoirhydraulic fracturingrock typesedimentary rockshale gastensile strengthunited states governmentupstream oil & gaswellbore design

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Bedey, K., Cunningham, A. B., Phillips, A. J., Kirkland, C. M., Willett, M. R., Dobeck, L., Eldring, J., Crandall, D., Rutqvist, J.. 2023-06-25. Developing Methods to Assess Changes in Mechanical Properties of Shale Modified by Engineered Mineral Precipitation. https://doi.org/10.56952/arma-2023-0807

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