{3D} {Modelling} of {Fluid} {Leakage} in a {Clay}-{Rich} {Fault} {Zone} {Using} {Geological} {Data}, {Borehole} {Imagery}, {Active} {Seismic} {Imaging}, and {DAS} {Fiber} {Optics}: {A} {Case} {Study} from the {Mont} {Terri} {Fault} {Activation} {Experimen

@inproceedings{Lannes2026RM,
 abstract = {This study investigates the three-dimensional architecture of the Main Fault at the Mont Terri Underground Rock Laboratory using a workflow that combines structural analysis of fault-core markers identified as “scaly clay” shear zones (i.e., a network of polished, anastomosing shear surfaces that form millimetric to centimetric scales), stochastic correlation of these markers using a graph-based approach, and implicit geological modelling using Aspen SKUA software, supplemented by the RINGToolKit research plug-in. Scaly clay interval orientation and thickness were measured on borehole optical logs and on cores. Then, their patterns were analysed to assess the internal organization and spatial segmentation of the fault zone. The results show that deformation is distributed across a several-meter-thick fault zone rather than localized along a single fault plane. Statistical analysis indicates a consistent direction of shear zones but significant variability in dip angles, suggesting that deformation was accommodated along multiple structures, including bedding-parallel to slip surfaces. Application of a graph-theory-based correlation method demonstrates that the observed fault markers cannot be reconciled within a single continuous fault surface. Instead, the most plausible scenarios involve at least three-to-four interconnected fault segments. Three-dimensional implicit models constructed from these scenarios reproduce the main structural families observed at Mont Terri. The resulting segmented fault zone architecture may explain hydraulic observations indicating compartmentalized fluid flow and strain variations within the fault zone during fluid injection experiments. These findings highlight the impact of fault-zone hydromechanical heterogeneity on fluid migration and rupture activation. Building a three-dimensional GOCAD geomodel through graph-theory-based correlation of geological datasets, and subsequently comparing it with geophysical data, appears as a promising way to provide probabilistic structural frameworks for fault zone characterization.},
 author = {Lannes, Emma and Guglielmi, Yves and Viseur, Sophie and Fratani, Amandine and Glubokovskikh, Stanislas and Nusbbaum, Christophe},
 booktitle = {2026 {RING} meeting},
 language = {en},
 pages = {131--138},
 publisher = {ASGA},
 title = {{3D} {Modelling} of {Fluid} {Leakage} in a {Clay}-{Rich} {Fault} {Zone} {Using} {Geological} {Data}, {Borehole} {Imagery}, {Active} {Seismic} {Imaging}, and {DAS} {Fiber} {Optics}: {A} {Case} {Study} from the {Mont} {Terri} {Fault} {Activation} {Experiment}.},
 year = {2026}
}