Modelling dc responses of 3-D complex fracture networks

Beskardes, G. D.; Weiss, Chester J.

doi:10.1093/gji/ggy234

Cited by 14 publications

(2 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The accuracy of the Hi ‐FEM for the Poisson's equation of the geophysical electrostatics has already been benchmarked against the analytical solutions of various models including buried disk, vertical cylinder, and vertical dike (Beskardes & Weiss, 2018; Weiss, 2017), which can be considered as reference for its validation for the steady‐state flow models.…”

Section: Validations and Applicationsmentioning

confidence: 99%

Finite Element Modeling of Diffusion in Fractured Porous Media by Using Hierarchical Material Properties

Beskardes

Weiss

Kuhlman

et al. 2022

Water Resources Research

View full text Add to dashboard Cite

Fractured rocks are the host for many engineered structures related to energy, water, waste, and transportation. For this reason, the functioning of such infrastructure, as well as optimization of its engineering efficiency, critically depends on characterizing, modeling, and monitoring fractured rock sites (National Academies of Sciences, 2015). Yet, modeling fluid flow in fractured porous media is a longstanding challenge due to the extensive numerical discretization and intractable computational cost imposed by discrete fractures and the matrix they are embedded within, where length scales span millimeter-scale fractures to the km-scale regions of the surrounding rock, all while attempting to achieve high model realism and accuracy for the correct management and reliable prediction of hydraulic and thermal behaviors of fractured rock masses. Not surprisingly, there has been a surge of interest on this research problem and it still remains interesting to many researchers due to its importance in a wide scope of applications such as geologic radioactive waste disposal (e.g.,

show abstract

Section: Validations and Applicationsmentioning

confidence: 99%

Finite Element Modeling of Diffusion in Fractured Porous Media by Using Hierarchical Material Properties

Beskardes

Weiss

Kuhlman

et al. 2022

Water Resources Research

View full text Add to dashboard Cite

show abstract

“…The primary reason for this has been the absence of tools for numerically modelling electric current flow in fractured media. Whereas fluid flow can be rather easily examined because the rock matrix is often ignored on the basis that it is effectively impervious (Neuman 2005;Maillot et al 2016;Cvetkovic 2017), this is not the case for the electrical conductivity where the matrix typically plays an important role in the conduction of electric current (Roubinet & Irving 2014;Roubinet et al 2016;Caballero Sanz et al 2017;Beskardes & Weiss 2018). As a result, modelling approaches that explicitly account for both the fractures and matrix, as well as interactions between these domains, are required.…”

Section: Introductionmentioning

confidence: 99%

Comparison of REV size and tensor characteristics for the electrical and hydraulic conductivities in fractured rock

Demirel

Irving

Roubinet

2018

Geophysical Journal International

View full text Add to dashboard Cite

The representative elementary volume (REV) is a critically important concept in fractured rock investigations as it tells us at what scale the fractured domain can be represented by an anisotropic tensor as opposed to requiring the details of each individual fracture for modelling purposes. Whereas the REV size and corresponding tensor characteristics for the hydraulic conductivity (K) in fractured rock have been the subject of numerous previous investigations, no studies to date have focused on the electrical conductivity (σ). This is despite the fact that geoelectrical measurements are arguably the most popular means of geophysically investigating fractured rock, typically via azimuthal resistivity surveying where the observed electrical anisotropy is commonly used to infer hydraulic characteristics. In this paper, we attempt to fill this void and present a systematic numerical study of the impacts of changes in fracturenetwork properties on the REV size and equivalent tensor characteristics for both the electrical and hydraulic conductivities. We employ a combined statistical and numerical approach where the size of the REV is estimated from the conductivity variability observed across multiple stochastic fracture-network realizations for various domain sizes. Two important differences between fluid and electric current flow in fractured media are found to lead to significant differences in the REV size and tensor characteristics for σ and K; these are the greater importance of the matrix in the electrical case and the single power instead of cubic dependence of electric current flow upon aperture. Specifically, the REV for the electrical conductivity will always be smaller than that for the hydraulic conductivity, and the corresponding equivalent tensor will exhibit less anisotropy, often with notably different principal orientations. These findings are of key importance for the eventual interpretation of geoelectrical measurements in fractured rock, where we conclude that extreme caution must be taken when attempting to make the link to hydraulic properties.

show abstract

Electromagnetic Modeling Using Adaptive Grids – Error Estimation and Geometry Representation

Spitzer

2023

Surv Geophys

View full text Add to dashboard Cite

This review paper addresses the development of numerical modeling of electromagnetic fields in geophysics with a focus on recent finite element simulation. It discusses ways of estimating errors of our solutions for a perfectly matched modeling domain and the problems that arise from its insufficient representation. After a brief outline of early methods and modeling approaches, the paper mainly discusses the capabilities of the finite element method formulated on unstructured grids and the advantages of local h-refinement allowing for both a flexible and largely accurate representation of the geometries of the multi-scale geomaterial and an accurate evaluation of the underlying functions representing the physical fields. In summary, the accuracy of the solution depends on the geometric mapping, the choice of the mathematical model, and the spatial discretization. Although the available error estimators do not necessarily provide reliable error bounds for our complex geomodels, they are still useful to guide grid refinement. Therefore, an overview of the most common a posteriori error estimators is given. It will be shown that the sensitivity is the most important function in both guiding the geometric mapping and the local refinement.

show abstract

Modelling dc responses of 3-D complex fracture networks

Cited by 14 publications

References 43 publications

Finite Element Modeling of Diffusion in Fractured Porous Media by Using Hierarchical Material Properties

Finite Element Modeling of Diffusion in Fractured Porous Media by Using Hierarchical Material Properties

Comparison of REV size and tensor characteristics for the electrical and hydraulic conductivities in fractured rock

Electromagnetic Modeling Using Adaptive Grids – Error Estimation and Geometry Representation

Contact Info

Product

Resources

About