CO2 leakage detection in the near-surface above natural CO2-rich water aquifer using soil gas monitoring

Jihyun Kim, Soonyoung Yu, Seong Taek Yun, Kyoung Ho Kim, Ji Hoon Kim, Young Jae Shinn, Gitak Chae

Research output: Contribution to journalArticlepeer-review

20 Citations (Scopus)


Conventional soil gas monitoring methods were applied above a natural low-level CO2 reservoir to locate natural CO2 leakage and assess effectiveness in monitoring geological carbon storage sites. The concentrations of the soil gas (N2, O2, and CO2) and carbon-13 isotopes of soil CO213CCO2) were determined for ninety-four soil gas samples that were collected at a depth of ∼60 cm. The CO2 flux was also measured at the same sampling locations. The 93 soil gas samples were divided into two groups: Group A with low soil CO2 concentrations and high δ13CCO2, which was influenced by the atmospheric air, and Group B with high soil CO2 concentrations and low δ13CCO2, which originated from microbial processes. Sample M17, which was close to a CO2-rich water well, had an exceptionally high soil CO2 (36.0% v/v), δ13CCO2 (-5.7‰), and flux (546.2 g/m2/d), indicating geogenic CO2 inflow to the soil layer and discharge through the surface. This study shows that conventional soil gas monitoring methods are useful for locating CO2 leakage. A dense grid soil CO2 sampling near wells and periodic investigations are crucial for further understanding of the CO2 flow paths in the soil layer.

Original languageEnglish
Pages (from-to)261-271
Number of pages11
JournalInternational Journal of Greenhouse Gas Control
Publication statusPublished - 2019 Sept


  • CO leakage
  • Carbon-13 isotope
  • Geological CO storage
  • Natural analogue
  • Near-surface geochemical monitoring

ASJC Scopus subject areas

  • Pollution
  • Energy(all)
  • Management, Monitoring, Policy and Law
  • Industrial and Manufacturing Engineering


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