Generally, carbon dioxide storage and sequestration projects require long term, but cost-effective monitoring, measuring, and verification (MMV) protocols for the duration of the combined injection and monitoring periods to be successful. MMV requires instrumentation and experimentation spanning several operational years and possibly decades. Few in situ instruments are capable of sustained multi-year deployments in such hostile subsurface environments. As a result, appropriate sensors for high resolution monitoring of carbon dioxide movement and resulting changes within the reservoir remain undeveloped.
In the oil and gas industry, the practice of temporarily lowering gravimetric sensors into boreholes to measure the rock and fluid properties of a geologic formation is well-known and referred to as well logging or borehole logging. However, as mentioned, well logging does not provide for long term monitoring, is temporary, and will fail to detect small conditional changes in a plume of carbon dioxide unless the well logging is performed at the proper time and proper depth. To ensure proper detection of carbon dioxide, well logging would have to be performed almost continuously.
Other methods are known that call for taking gravimetric measurements at the surface of a geographical formation and then creating a model to project vertically and predict the subsurface conditions. No known methods include taking subsurface gravimetric measurements and using them to project inter-sensor lateral and vertical movements of subsurface plumes.
USPTO Backgrounds
USPTO Backgrounds