Accurate modeling and inversion of electrical resistivity data in the presence of metallic infrastructure with known location and dimension
Abstract
Electrical resistivity tomography (ERT) has been widely used in environmental applications to study processes associated with subsurface contaminants and contaminant remediation. Anthropogenic alterations in subsurface electrical conductivity associated with contamination often originate from highly industrialized areas with significant amounts of buried metallic infrastructure. The deleterious influence of such infrastructure on imaging results generally limits the utility of ERT where it might otherwise prove useful for subsurface investigation and monitoring. In this manuscript we present a method of accurately modeling the effects of buried conductive infrastructure within the forward modeling algorithm, thereby removing them from the inversion results. The method is implemented in parallel using immersed interface boundary conditions, whereby the global solution is reconstructed from a series of well-conditioned partial solutions. Forward modeling accuracy is demonstrated by comparison with analytic solutions. Synthetic imaging examples are used to investigate imaging capabilities within a subsurface containing electrically conductive buried tanks, transfer piping, and well casing, using both well casings and vertical electrode arrays as current sources and potential measurement electrodes. Results show that, although accurate infrastructure modeling removes the dominating influence of buried metallic features, the presence of metallic infrastructure degrades imaging resolution compared to standard ERT imaging. However, accurate imaging resultsmore »
- Authors:
- Publication Date:
- Research Org.:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Org.:
- USDOE
- OSTI Identifier:
- 1208736
- Report Number(s):
- PNNL-SA-104673
830403000
- DOE Contract Number:
- AC05-76RL01830
- Resource Type:
- Journal Article
- Journal Name:
- Geophysical Journal International, 202(2):1096-1108
- Additional Journal Information:
- Journal Name: Geophysical Journal International, 202(2):1096-1108
- Country of Publication:
- United States
- Language:
- English
- Subject:
- resistivity; tomography; imaging; inversion; numerical solutions; parallel computing
Citation Formats
Johnson, Timothy C., and Wellman, Dawn M. Accurate modeling and inversion of electrical resistivity data in the presence of metallic infrastructure with known location and dimension. United States: N. p., 2015.
Web. doi:10.1093/gji/ggv206.
Johnson, Timothy C., & Wellman, Dawn M. Accurate modeling and inversion of electrical resistivity data in the presence of metallic infrastructure with known location and dimension. United States. https://doi.org/10.1093/gji/ggv206
Johnson, Timothy C., and Wellman, Dawn M. 2015.
"Accurate modeling and inversion of electrical resistivity data in the presence of metallic infrastructure with known location and dimension". United States. https://doi.org/10.1093/gji/ggv206.
@article{osti_1208736,
title = {Accurate modeling and inversion of electrical resistivity data in the presence of metallic infrastructure with known location and dimension},
author = {Johnson, Timothy C. and Wellman, Dawn M.},
abstractNote = {Electrical resistivity tomography (ERT) has been widely used in environmental applications to study processes associated with subsurface contaminants and contaminant remediation. Anthropogenic alterations in subsurface electrical conductivity associated with contamination often originate from highly industrialized areas with significant amounts of buried metallic infrastructure. The deleterious influence of such infrastructure on imaging results generally limits the utility of ERT where it might otherwise prove useful for subsurface investigation and monitoring. In this manuscript we present a method of accurately modeling the effects of buried conductive infrastructure within the forward modeling algorithm, thereby removing them from the inversion results. The method is implemented in parallel using immersed interface boundary conditions, whereby the global solution is reconstructed from a series of well-conditioned partial solutions. Forward modeling accuracy is demonstrated by comparison with analytic solutions. Synthetic imaging examples are used to investigate imaging capabilities within a subsurface containing electrically conductive buried tanks, transfer piping, and well casing, using both well casings and vertical electrode arrays as current sources and potential measurement electrodes. Results show that, although accurate infrastructure modeling removes the dominating influence of buried metallic features, the presence of metallic infrastructure degrades imaging resolution compared to standard ERT imaging. However, accurate imaging results may be obtained if electrodes are appropriately located.},
doi = {10.1093/gji/ggv206},
url = {https://www.osti.gov/biblio/1208736},
journal = {Geophysical Journal International, 202(2):1096-1108},
number = ,
volume = ,
place = {United States},
year = {Fri Jun 26 00:00:00 EDT 2015},
month = {Fri Jun 26 00:00:00 EDT 2015}
}