Distributed Sensors for Dissolved Carbon Dioxide

Reliable and cost-effective monitoring is important to making storage of industrially generated carbon dioxide in deep geologic reservoirs safe and acceptable. Sequestration sites must be monitored before injection, during injection, in the closure phase, and in the post-closure phase (when ongoing monitoring must demonstrate that the storage project is performing as expected). Contamination of shallow water above the carbon dioxide reservoir is a risk if there is a gas leak. Timely detection of chemical changes produced by carbon dioxide solubilization in aquifers provides not only information about the migration path of the gas, but an alarm to start remediation, especially if potable water is affected. For near-surface monitoring and ground water monitoring, sampling of water near the surface for basic chemical analysis is one the methods under consideration. However, sampling followed by laboratory analysis is far too costly and labor-intensive for long term monitoring of large areas. Improvements over current techniques are needed by organizations performing carbon dioxide sequestration. To overcome current limitations, Intelligent Optical Systems, Inc. (IOS) proposes to develop the world's first truly distributed dissolved carbon dioxide sensors, based on optical fibers coated with doped polymers, for spatially resolved shallow water monitoring of carbon dioxide during and after geological sequestration. New carbon dioxide sensitive materials incorporating fluorescent indicators will be developed, building on and improving the technology used in single point optical sensors of dissolved carbon dioxide. This system will monitor for gas leaks, but more importantly, will quantify the effect of the carbon dioxide leaked into aquifers, key information required to start remediation. Commercial Applications and Other Benefits: Carbon dioxide geological sequestration is expected to be widely used in the near future. Governments and private sector entities (especially in the gas industry) are investing and will increase resources for this technology for carbon dioxide emission mitigation. Several commercial and demonstration projects already require improved monitoring technologies. The unique fully-distributed sensor we propose to develop is ideally suited for monitoring carbon dioxide in large-scale geological and hydrological structures, so the commercial opportunity is ripe in this growing field. Monitoring of storage locations is required not only before and during injection but long after the closure phase, creating a secondary commercial opportunity linked to post-sale support.