GEOPHYSICAL SENSING FOR CO2 SEQUESTRATION AND EOR

This paper reports a study proposing the use of geophysical testing techniques to monitor the effects of carbon dioxide (CO2) in a test well in the Citronelle Oil Field in Mobile, Alabama. This mature and water-flooded oil reservoir is ideal for both CO2 sequestration and enhanced oil recovery (EOR) due to its structural features. Both the site characterization tests before the CO2 injection and the monitoring after injection will be conducted using surface and downhole seismic tests to detect and observe wave propagations and reflections through the soil medium. Spectral analysis of various wave propagations will be conducted in order to delineate wave components. The success of CO2 migration monitoring in the oil reservoir can prevent possible leakage of CO2 back into the atmosphere, hence reduce its environmental impacts. Since the Citronelle Oil Field is located in the vicinity of a concentrated population, innovative seismic measurement techniques that can reduce disturbance to the neighborhoods are to be explored. Ultra-sensitive transducers must be used, including geophones, wireless accelerometer and wired sensors. Other challenges may also include strategies in data management and processing, as well as keeping track of sensor operation for both anthropogenic impact and ambient excitation.