Experimental study for visualizing CO-dissolved water plume migration under hydraulic gradient conditions and implication for field monitoring data.

Investigating the possible direction of a CO-dissolved water plume migration near the potential CO leakage area is a significant task because it helps estimate the spatial and temporal monitoring scale to detect the signal of released CO from the storage. Accordingly, the Korea CO Storage Environmental Management (K-COSEM) research center tried to develop an intensive monitoring system and applied it to the artificial CO release test in the actual field. Monitoring data from the field tests depicted the horizontal movement of the CO-dissolved water plume along the direction of the groundwater flow.

A modified and rapid method for the single-well push-pull (SWPP) test using SF, Kr, and uranine tracers.

In the present study, a single-well push-pull (SWPP) test was conducted with multi-component tracers, including inert gas (SF and Kr) and uranine (conservative), to understand the volatile/semi-volatile component transport characteristics in the groundwater system. In an SWPP test, it is essential to obtain an initial breakthrough curve (BTC) of the inert gas concentration at the beginning of the pulling stage to analyze the hydraulic properties of the groundwater system. As a result of the SWPP test using a proposed method in this study, physicochemical parameters of the groundwater and BTC of gas tracers and uranine were acquired simultaneously and successfully.

Constraining the effectiveness of inherent tracers of captured CO for tracing CO leakage: Demonstration in a controlled release site.

Geological storage of carbon dioxide (CO) is an integral component of cost-effective greenhouse gas emissions reduction scenarios. However, a robust monitoring regime is necessary for public and regulatory assurance that any leakage from a storage site can be detected. Here, we present the results from a controlled CO release experiment undertaken at the K-COSEM test site (South Korea) with the aim of demonstrating the effectiveness of the inherent tracer fingerprints (noble gases, δC) in monitoring CO leakage.

Reproducing natural variations in CO concentration in vadose zone wells with observed atmospheric pressure and groundwater data.

Continuous CO gas monitoring was performed to understand the natural variations of the gas concentration in the vadose zone wells. The monitoring results demonstrated sudden rise and fall signals, which posed a possibility of error in interpreting the CO leaking signal from the sequestrating reservoir or evaluating the quantity of removed VOCs at a contaminated site. Based on the monitoring data, conceptual models were established and three cases were numerically simulated to determine whether or not reproducing the natural variations of gas concentration is possible.

Real-time multi-level CO concentration monitoring in vadose zone wells and the implication for detecting leakage events.

Multi-level wells screened at different depths in the vadose zone were installed and used for CO and carbon isotope monitoring. Well CO time series data were collected along with subsurface and atmospheric parameters such as air pressure, temperature, wind speed, and moisture content. Our aim was to determine the natural factors affecting the variation of CO concentration and how the influence of these factors varies with time of day and seasons of the year.