A HIGHLY SENSITIVE REAL-TIME SUBSURFACE SENSOR FOR CO2 LEAKAGE MONITORING

Carbon capture and storage (CCS) is of great importance in reducing greenhouse gases such as carbon dioxide (CO2) that are emitted by industrial processes. In order to establish and maintain a safe and long- lasting CCS state, the subsurface CO2 reservoir’s condition needs to be pre-evaluated and continuously monitored. One of the major concerns with CCS operation is CO2 leakage, as this could potentially result in significant release of CO2 back to the atmosphere, reducing the practical effectiveness of CCS and being very costly to fix, or into the groundwater. At present there are no real-time detection techniques that can reliably quantify CO2 leakage information in a timely manner with highly sensitive signal feedbacks. The successful development of a highly sensitive, real-time and cost-effective sensor system for subsurface CO2 leakage detection will have a significant impact on the CCS operation, reducing their capital and operating costs and increasing their use. In this SBIR program, Bettergy proposes to develop a novel microwave coaxial cable Fabry-Perot interferometric sensor for low concentration CO2 detection with high robustness, high sensitivity, high detection limit and fast response time that suits for CO2 leakage detections in current CCS operations. This technology will involve a new material and a novel sensor concept investigation, with existing analytical methods for fast and accurate signal interpretation. The sensor will be easy to install into downhole wellbores with its “plug-and-play” feature and a small size, while the manufacturing could be simple with a low cost. This novel sensor is well-positioned to meet the long lasting challenges for subsurface condition CO2 detection with a huge potential to be developed as long distance distributed sensor and will fit with the ever growing downhole tool market. CCS is recognized as a powerful tool for addressing CO2 mitigation in the air due to its safe, sustainable and cost-effective nature and there has been tremendous support of research and commercialization efforts led by the DOE and other agencies. However, concerns have been raised, including by the Environmental Protection Agency (EPA), such as subsurface CO2 leakage could potentially harm the underground sources of drinking water and cause health problems to human and animal life in local areas. There is a necessity for fast, accurate and cost-effective detection of CO2 leakage, and as a result, the related “downhole tools” market is predicted to be $5.16 billion by 2026. A real-time, highly sensitive, robust and low cost downhole sensor that can be implemented in a “plug-and- play” manner open up opportunities for us to enter the market and provide new possibilities for sensor concepts that can be used in other applications in which harsh environments will be encountered.