Field Test of in Situ Sensor Technology for Process-based Soil Gas Monitoring

Abstract

Abstract A process-based approach to soil gas monitoring at geologic carbon storage sites may provide an accurate, simple, and cost- effective alternative to other soil gas methods that require lengthy background data collection and complex statistical analysis. However, in order for this method to be implemented on an industrial scale, continuous smart data collection of the necessary parameters for a process-based analysis (e.g. N 2 , CH 4 , CO 2 , O 2 and H 2 O) is required. Commercially-available sensors for CH4, O 2 , relative humidity (RH), and CO 2 were screened and found to possess factory-derived accuracies that meet the desired specifications for implementing the process-based method in the field; however appropriate sensor technology for N2 is not currently available. We report the preliminary results of a field test to develop a method for continuous process-based data collection using commercially-available, automated sensors that measure CO 2 , CH4, O2, temperature, RH, and pressure, and deriving N2 by subtraction.