Portable Mid-Infrared Sensor System for Monitoring CO2 and CH4 at High Pressure in Geosequestration Scenarios

Abstract

A portable infrared attenuated total reflection (IR-ATR) spectrometer was developed for analyzing CO2 and CH4 in geosequestration scenarios. This infrared-based online sensor system is suitable for monitoring, detecting, and differentiating carbon dioxide and methane at different pressures (i.e., up to 11 MPa) in saline aquifer and/or synthetic brine environments. The design of the sensor system eliminates the present problems in such measurement scenarios of either portability or capability operating at harsh conditions, and especially at elevated pressures for in-field deployment of current available IR systems. It is demonstrated that the detection and quantification of dissolved CO2 and CH4 at pressurized conditions is feasible at relevant saline downhole conditions present within the piping of the present injection wells serving as an online/in-line monitoring tool.