3-D hydromechanical simulation of intersecting faults: Influences on fluid circulation and formation of oriented-orebodies

Khalifa Eldursi and Luc Scholtes and Marianne Conin and Fabrice Golfier and Patrick Ledru and Julien Mercadier and Pauline Collon and Remy Chemillac. ( 2023 )
in: Journal of Structural Geology, 171 (104864)

Abstract

Although intersection zones of two or more fault arrays have been identified as favorable loci of unconformity- related basin-basement mineral deposits in previous studies, their roles in controlling fluid flow patterns related to formation of oriented-, and structurally-controlled mineral deposits remain unclear. In this study, 3-D hydromechanical models were conducted to better understand the response of a natural fault intersected by a hydraulic fault under different stress regimes. A comprehensive parametric study was carried out to assess the roles of fluid pressure, burial depth, basin permeability, intersection angle, and horizontal differential stress on the hydromechanical response of a system containing two intersecting faults. Depending on basin sediment permeability, fault intersection angle, and horizontal differential stress, the fluid flow either stops, crosses, or diverts toward natural fault. Among the tested parameters, the intersection angle, and horizontal differential stress have the most noticeable effect on the fluid flow in the system. The critical intersection angle at which the fluid flow diverts toward the natural fault varies between ≈27° in normal faulting regimes, to ≈55°, in both strike-slip and reverse faulting regimes. Conversely, burial depth and fluid pressure have no significant effect on fluid flow diversion in the intersection zone. The results are in agreement with field observations related to the unconformity-related uranium deposits found in northern Canada

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BibTeX Reference

@article{eldursi:hal-04118370,
 abstract = {Although intersection zones of two or more fault arrays have been identified as favorable loci of unconformity- related basin-basement mineral deposits in previous studies, their roles in controlling fluid flow patterns related to formation of oriented-, and structurally-controlled mineral deposits remain unclear. In this study, 3-D hydromechanical models were conducted to better understand the response of a natural fault intersected by a hydraulic fault under different stress regimes. A comprehensive parametric study was carried out to assess the roles of fluid pressure, burial depth, basin permeability, intersection angle, and horizontal differential stress on the hydromechanical response of a system containing two intersecting faults. Depending on basin sediment permeability, fault intersection angle, and horizontal differential stress, the fluid flow either stops, crosses, or diverts toward natural fault. Among the tested parameters, the intersection angle, and horizontal differential stress have the most noticeable effect on the fluid flow in the system. The critical intersection angle at which the fluid flow diverts toward the natural fault varies between ≈27° in normal faulting regimes, to ≈55°, in both strike-slip and reverse faulting regimes. Conversely, burial depth and fluid pressure have no significant effect on fluid flow diversion in the intersection zone. The results are in agreement with field observations related to the unconformity-related uranium deposits found in northern Canada},
 author = {Eldursi, Khalifa and Scholtes, Luc and Conin, Marianne and Golfier, Fabrice and Ledru, Patrick and Mercadier, Julien and Collon, Pauline and Chemillac, Remy},
 doi = {10.1016/j.jsg.2023.104864},
 hal_id = {hal-04118370},
 hal_version = {v1},
 journal = {{Journal of Structural Geology}},
 keywords = {Fault intersection ; Fault activation ; Structurally-controlled mineral deposits ; 3-D hydromechanical modeling ; Uranium deposits ; Athabasca basin},
 month = {June},
 pages = {104864},
 pdf = {https://hal.univ-lorraine.fr/hal-04118370/file/Eldursi%20et%20al%202023.%20HAL%20Format.pdf},
 publisher = {{Elsevier}},
 title = {{3-D hydromechanical simulation of intersecting faults: Influences on fluid circulation and formation of oriented-orebodies}},
 url = {https://hal.univ-lorraine.fr/hal-04118370},
 volume = {171},
 year = {2023}
}