Abstract
Abstract Progressive cementation and sealing of fault-localized fractures impact crustal mass transport and the recovery of fault strength following slip events. We use discrete fracture network (DFN) models to examine how fracture sealing during end-member cementation mechanisms (i.e., reaction- versus transported-limited cementation) influences the partitioning of fluid flow through time. DfnWorks was used to generate randomized fracture networks parameterized with fracture orientation data compiled from field studies. Single-phase flow simulations were performed for each network over a series of timesteps, and network parameters were modified to reflect progressive fracture sealing consistent with either reaction- or transport-limited crystal growth. Results show that when fracture cementation is reaction-limited, fluid flow becomes progressively channelized into a smaller number of fractures with larger apertures. When fracture cementation is transport-limited, fluid flow experiences progressive dechannelization, becoming more homogeneously distributed throughout the fracture network. These behaviors are observed regardless of the DFN parameterization, suggesting that the effect is an intrinsic component of all fracture networks subjected to the end-member cementation mechanisms. These results have first-order implications for the spatial distribution of fluid flow in fractured rocks and recovery of permeability and strength during fault/fracture healing in the immediate aftermath of fault slip.
Highlights
Brittle fractures in fault zones exert a first-order control on the hydrological and mechanical properties of the upper crust
When mineral growth in fractures is reaction limited, the locus of fluid flow and cementation becomes increasingly channelized within discrete segments of the fracture networks through time (e.g., [45])
Models were constructed using the software dfnWorks and were parameterized with fracture geometry data from real fault damage zones. We find that these two endmember mechanisms of mineral precipitation have opposite effects on the distribution of fluid flow and cementation in fault-zone fracture networks
Summary
Brittle fractures in fault zones exert a first-order control on the hydrological and mechanical properties of the upper crust. Understanding their distribution, properties, and evolution is essential for a variety of geological applications. Increased fracture-related permeability along faults may provide pathways for the migration and accumulation of hydrocarbons [7,8,9,10]. The occurrence and longevity of fault-related fractures is an active and long-lived area of research with substantial societal implications. Research in this area is complicated; by the fact that fault-zone fracture networks are not static structures in the crust. A variety of rock record, geophysical, and experimental studies indicate that fracture systems are dynamic, repeatedly opening and closing throughout fault history [1, 15, 16, 20,21,22,23,24]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
