Crosshole IP imaging for engineering and environmental applications

• Andreas Kemna

  Formerly Deutsche Montan Technologie GmbH, 45307 Essen, Germany; presently Agrosphere Institute (ICG‐IV), Forschungszentrum Jülich, 52425 Jülich, Germany.

• Andrew Binley

  Lancaster University, Department of Environmental Science, Lancaster LA1 4YQ, United Kingdom.

• Lee Slater

  Formerly University of Missouri–Kansas City, Department of Geosciences, Kansas City, Missouri 64110; presently Rutgers University, Department of Earth/Environmental Sciences, 195 College Avenue, Newark, New Jersey 07102.

抄録

Induced polarization (IP) imaging is a promising tool in engineering and environmental studies. Application of this technique for near‐surface investigations has previously been limited by incomplete understanding of the physicochemical controls on the IP response, together with a lack of appropriate methods for data inversion. As laboratory studies have shown, description of IP in terms of complex electrical conductivity enables access to various structural characteristics pertinent to practical issues such as subsurface lithology definition, hydraulic permeability estimation, or hydrocarbon contaminant mapping. In particular, analysis in terms of real and imaginary conductivity components offers improved lithological characterization, since surface polarization effects are separated from electrolytic and surface conduction effects. An Occam‐type IP inversion algorithm based on complex algebra is described which accounts for these advances in IP interpretation by directly solving for complex conductivity. Results from crosshole applications at two case study sites demonstrate the suitability of the IP imaging approach for subsurface characterization. In the first case study, the imaging results correlate with the observed complex sequence of Quaternary sediments at a waste disposal site. Characterization of the polarizability of these sediments offers significant value in lithological differentiation. In the second case study, the results of IP imaging at a hydrocarbon‐contaminated site illustrate the potential of the method in environmental studies. The hydrocarbon location is clearly evident from the IP image, and a markedly different response is observed at an uncontaminated region of the site. By adopting empirical structural–electrical relationships, images of textural and hydraulic properties are estimated as a step toward improved quantitative characterization. The success of the method for these contrasting applications supports further investigation into understanding the physical and chemical processes that control observed IP.

収録刊行物

• GEOPHYSICS

  GEOPHYSICS 69 (1), 97-107, 2004-01

  Society of Exploration Geophysicists

キーワード

• Geochemistry and Petrology
• Geophysics

詳細情報

• CRID: 1363670318410468608
• NII論文ID: 30022775231
• DOI: 10.1190/1.1649379
• ISSN: 19422156
• ISSN: 00168033
• Web Site: https://library.seg.org/doi/pdf/10.1190/1.1649379
• データソース種別:
  • Crossref
  • CiNii Articles