Modeling Utah FORGE 2022 EGS Hydraulic Stimulations: Tensile Hydraulic Fractures versus Fluid-Induced Dilatant Shear Ruptures

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Brisson, Sylvain, Lecampion, Brice
Natura: Preprint
Pubblicazione: 2026
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866917422364098560
author Brisson, Sylvain
Lecampion, Brice
author_facet Brisson, Sylvain
Lecampion, Brice
contents We investigate two hydraulic stimulation stages performed in April 2022 at the Utah FORGE enhanced geothermal system test site using analytical and numerical models for tensile hydraulic fractures and fluid-induced dilatant shear fractures. The two injection stages differ primarily by the viscosity of the fracturing fluid. Despite similar injection rate schedules and well-head pressure responses, the two stages exhibit markedly different post-shut-in microseismic behavior. The cross-linked gel stage shows sustained microseismic activity for several hours after shut-in, whereas the slickwater stage exhibits an immediate decrease. For the cross-linked gel stage, the located microseismic events reveal the development of a planar radial fracture and allow confident retrieval of the fracture extent evolution with time. We demonstrate that this evolution follows the scalings predicted for viscosity-storage-dominated radial hydraulic fracture by analytical models, providing strong evidence for the development of a planar tensile hydraulic fracture. We further show that leak-off is required to reproduce the fracture extent. In contrast, the immediate arrest observed during the slick-water stage suggests either a transition to a toughness- or leak-off-dominated hydraulic fracture regime, or the development of a fluid-induced shear fracture. We show that the slickwater stage could plausibly correspond to a dilatant shear fracture, provided sufficient dilatancy, whereas this hypothesis is invalidated for the cross-linked gel stage. We confirm these insights using a 3D axisymmetric fully-coupled hydro-mechanical numerical model capable of resolving both tensile and shear failure modes, and including leak-off. Finally, we propagate uncertainties in the in-situ stress state and natural fracture orientations through this numerical model to assess their impact on injection pressures.
format Preprint
id arxiv_https___arxiv_org_abs_2604_17990
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Modeling Utah FORGE 2022 EGS Hydraulic Stimulations: Tensile Hydraulic Fractures versus Fluid-Induced Dilatant Shear Ruptures
Brisson, Sylvain
Lecampion, Brice
Geophysics
We investigate two hydraulic stimulation stages performed in April 2022 at the Utah FORGE enhanced geothermal system test site using analytical and numerical models for tensile hydraulic fractures and fluid-induced dilatant shear fractures. The two injection stages differ primarily by the viscosity of the fracturing fluid. Despite similar injection rate schedules and well-head pressure responses, the two stages exhibit markedly different post-shut-in microseismic behavior. The cross-linked gel stage shows sustained microseismic activity for several hours after shut-in, whereas the slickwater stage exhibits an immediate decrease. For the cross-linked gel stage, the located microseismic events reveal the development of a planar radial fracture and allow confident retrieval of the fracture extent evolution with time. We demonstrate that this evolution follows the scalings predicted for viscosity-storage-dominated radial hydraulic fracture by analytical models, providing strong evidence for the development of a planar tensile hydraulic fracture. We further show that leak-off is required to reproduce the fracture extent. In contrast, the immediate arrest observed during the slick-water stage suggests either a transition to a toughness- or leak-off-dominated hydraulic fracture regime, or the development of a fluid-induced shear fracture. We show that the slickwater stage could plausibly correspond to a dilatant shear fracture, provided sufficient dilatancy, whereas this hypothesis is invalidated for the cross-linked gel stage. We confirm these insights using a 3D axisymmetric fully-coupled hydro-mechanical numerical model capable of resolving both tensile and shear failure modes, and including leak-off. Finally, we propagate uncertainties in the in-situ stress state and natural fracture orientations through this numerical model to assess their impact on injection pressures.
title Modeling Utah FORGE 2022 EGS Hydraulic Stimulations: Tensile Hydraulic Fractures versus Fluid-Induced Dilatant Shear Ruptures
topic Geophysics
url https://arxiv.org/abs/2604.17990