Potential for the Use of Wireless Sensor Networks for Monitoring of CO2 Leakage Risks

Abstract:

Storage of supercritical CO₂ in deep saline geologic formation is under study as a means to mitigate potential global climate change from green house gas loading to the atmosphere. Leakage of CO₂ from these formations poses risk to the storage permanence goal of 99% of injected CO₂ remaining sequestered from the atmosphere,. Leaked CO₂ that migrates into overlying groundwater aquifers may cause changes in groundwater quality that pose risks to environmental and human health. For these reasons, technologies for monitoring, measuring and accounting of injected CO₂ are necessary for permitting of CO₂ sequestration projects under EPA’s class VI CO₂ injection well regulations. While the probability of leakage related to CO₂ injection is thought to be small at characterized and permitted sites, it is still very important to protect the groundwater resources and develop methods that can efficiently and accurately detect CO₂ leakage. Methods that have been proposed for leakage detection include remote sensing, soil gas monitoring, geophysical techniques, pressure monitoring, vegetation stress and eddy covariance measurements. We have demonstrated the use of wireless sensor networks (WSN) for monitoring of subsurface contaminant plumes. The adaptability of this technology for leakage monitoring of CO₂ through geochemical changes in the shallow subsurface is explored. For this technology to be viable, it is necessary to identify geochemical indicators such as pH or electrical conductivity that have high potential for significant change in groundwater in the event of CO₂ leakage. This talk presents a conceptual approach to use WSNs for CO₂ leakage monitoring. Based on our past work on the use of WSN for subsurface monitoring, some of the challenges that need to be over come for this technology to be viable for leakage detection will be discussed.