Discontinuities in effective permeability due to fracture percolation
Abstract
Motivated by a triaxial coreflood experiment with a sample of Utica shale where an abrupt jump in permeability was observed, possibly due to the creation of a percolating fracture network through the sample, we perform numerical simulations based on the experiment to characterize how the effective permeability of otherwise lowpermeability porous media depends on fracture formation, connectivity, and the contrast between the fracture and matrix permeabilities. While a change in effective permeability due to fracture formation is expected, the dependence of its magnitude upon the contrast between the matrix permeability and fracture permeability and the fracture network structure is poorly characterized. We use two different highfidelity fracture network models to characterize how effective permeability changes as percolation occurs. The first is a dynamic twodimensional fracture propagation model designed to mimic the laboratory settings of the experiment. The second is a static threedimensional discrete fracture network (DFN) model, whose fracture and network statistics are based on the fractured sample of Utica shale. Once the network connects the inflow and outflow boundaries, the effective permeability increases nonlinearly with network density. In most networks considered, a jump in the effective permeability was observed when the embedded fracture network percolated. We characterize how themore »
 Authors:
 Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
 Publication Date:
 Research Org.:
 Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
 Sponsoring Org.:
 USDOE Laboratory Directed Research and Development (LDRD) Program
 OSTI Identifier:
 1419753
 Report Number(s):
 LAUR1723142
Journal ID: ISSN 01676636
 Grant/Contract Number:
 AC5206NA25396
 Resource Type:
 Journal Article: Accepted Manuscript
 Journal Name:
 Mechanics of Materials
 Additional Journal Information:
 Journal Volume: 119; Journal Issue: C; Journal ID: ISSN 01676636
 Publisher:
 Elsevier
 Country of Publication:
 United States
 Language:
 English
 Subject:
 36 MATERIALS SCIENCE; Computer Science; Earth Sciences; Energy Sciences; Mathematics; Flow in porous media; Discrete fracture networks; Percolation
Citation Formats
Hyman, Jeffrey De'Haven, Karra, Satish, Carey, James William, Gable, Carl Walter, Viswanathan, Hari S., Rougier, Esteban, and Lei, Zhou. Discontinuities in effective permeability due to fracture percolation. United States: N. p., 2018.
Web. doi:10.1016/j.mechmat.2018.01.005.
Hyman, Jeffrey De'Haven, Karra, Satish, Carey, James William, Gable, Carl Walter, Viswanathan, Hari S., Rougier, Esteban, & Lei, Zhou. Discontinuities in effective permeability due to fracture percolation. United States. doi:10.1016/j.mechmat.2018.01.005.
Hyman, Jeffrey De'Haven, Karra, Satish, Carey, James William, Gable, Carl Walter, Viswanathan, Hari S., Rougier, Esteban, and Lei, Zhou. 2018.
"Discontinuities in effective permeability due to fracture percolation". United States.
doi:10.1016/j.mechmat.2018.01.005.
@article{osti_1419753,
title = {Discontinuities in effective permeability due to fracture percolation},
author = {Hyman, Jeffrey De'Haven and Karra, Satish and Carey, James William and Gable, Carl Walter and Viswanathan, Hari S. and Rougier, Esteban and Lei, Zhou},
abstractNote = {Motivated by a triaxial coreflood experiment with a sample of Utica shale where an abrupt jump in permeability was observed, possibly due to the creation of a percolating fracture network through the sample, we perform numerical simulations based on the experiment to characterize how the effective permeability of otherwise lowpermeability porous media depends on fracture formation, connectivity, and the contrast between the fracture and matrix permeabilities. While a change in effective permeability due to fracture formation is expected, the dependence of its magnitude upon the contrast between the matrix permeability and fracture permeability and the fracture network structure is poorly characterized. We use two different highfidelity fracture network models to characterize how effective permeability changes as percolation occurs. The first is a dynamic twodimensional fracture propagation model designed to mimic the laboratory settings of the experiment. The second is a static threedimensional discrete fracture network (DFN) model, whose fracture and network statistics are based on the fractured sample of Utica shale. Once the network connects the inflow and outflow boundaries, the effective permeability increases nonlinearly with network density. In most networks considered, a jump in the effective permeability was observed when the embedded fracture network percolated. We characterize how the magnitude of the jump, should it occur, depends on the contrast between the fracture and matrix permeabilities. For small contrasts between the matrix and fracture permeabilities the change is insignificant. However, for larger contrasts, there is a substantial jump whose magnitude depends nonlinearly on the difference between matrix and fracture permeabilities. A powerlaw relationship between the size of the jump and the difference between the matrix and fracture permeabilities is observed. In conclusion, the presented results underscore the importance of fracture network topology on the upscaled properties of the porous medium in which it is embedded.},
doi = {10.1016/j.mechmat.2018.01.005},
journal = {Mechanics of Materials},
number = C,
volume = 119,
place = {United States},
year = 2018,
month = 1
}

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