Using Low-Field Nuclear Magnetic Resonance and X-Ray Computed Microtomography Imaging to Explore Potential of Microbially-Induced Calcium Carbonate Precipitation Treatment to Seal Shale Fractures

Conference · Sun Jun 25 04:00:00 EDT 2023 · 57th U.S. Rock Mechanics/Geomechanics Symposium

DOI:https://doi.org/10.56952/arma-2023-0804· OSTI ID:2478669

Willett, M. R. ^[1]; Seymour, J. D. ^[2]; Bedey, K. ^[2]; Kirkland, C. M. ^[2]; Phillips, A. J. ^[2]; Cunningham, A. B. ^[2]; Dobeck, L. ^[2]; Crandall, D. ^[3]; Rutqvist, J. ^[4]

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1. Montana State University, Bozeman, MT (United States); Montana State University
2. Montana State University, Bozeman, MT (United States)
3. National Energy Technology Laboratory (NETL), Morgantown, WV (United States)
4. Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)

Microbially-induced calcium carbonate precipitation (MICP) is a biological process in which microbially produced urease enzymes convert urea and calcium into solid calcium carbonate (CaCO₃) deposits. Studies have shown that MICP can be used to seal fractures in shale, raising the possibility of applying this technology to restimulate fracking wells by plugging underperforming fractures. For this and other applications to become a reality, non-invasive tools are needed to determine how effectively MICP seals shale fractures under subsurface conditions. In this study, a 2.54 cm wide and 5.08 cm long Marcellus shale core with a single, ~1 mm wide fracture held open by sand "proppant" underwent MICP-treatment at 60°C until reaching three orders of magnitude permeability reduction. Low-field nuclear magnetic resonance (LF-NMR) and X-Ray computed microtomography (μ-CT) techniques were used to assess the extent of biomineralization within the fracture. These tools revealed that while CaCO₃ precipitation occurred throughout the fracture, there was preferential precipitation around proppant, and the core sealed at the effluent end before filling most of the fracture. Both tools were able to independently calculate of the amount of solid biomineral formed inside the fracture. Furthermore, this study found that the distribution of proppant within the shale fracture was an important parameter controlling the degree of biomineralization.

• Research Organization: Montana State University, Bozeman, MT (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: SC0021324
• OSTI ID: 2478669
• Conference Information: Journal Name: 57th U.S. Rock Mechanics/Geomechanics Symposium
• Country of Publication: United States
• Language: English

Related Subjects

clastic rock
complex reservoir
fluid dynamics
fracturing materials
geologist
proppant
sedimentary rock
shale gas
structural geology
united states government