Tracers are used to tag the injected carbon dioxide (CO2) for verification of the storage performance and containment in geosequestration. Yet the characterization of the transport behavior of a chemical tracer in two-phase flow system has not been fully investigated. We present experimental observations together with numerical results for both homogeneous and heterogeneous media from core scale to field scale. The key features of the breakthrough curves (BTCs) that include the tracer arrival time, peak concentration, and tailing pattern were examined. We identify distinct differences in BTCs depending on whether the formation was previously swept by CO2. When the tracer is released before CO2 sweeps the formation, the tracer transports at the front of gas-liquid interfaces with a narrow tracer plume distribution and the BTCs reflect the effect of local heterogeneity. Furthermore, a series of tracer pulse can be used to identify whether new pathways have been developed during CO2 injection.
Bibliographical noteFunding Information:
This research was supported by the Basic Research Project of the Korea Institute of Geoscience and Mineral Resources (KIGAM) funded by the Ministry of Science and ICT, as well as the Korea Environment Industry & Technology Institute (KEITI) through the Subsurface Environment Management (SEM) Project, funded by the Ministry of Environment (MOE) (2018002440004). We thank Dr. Susan Hovorka and one anonymous reviewer, whose constructive comments helped greatly improve the quality of the paper.
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All Science Journal Classification (ASJC) codes
- Earth and Planetary Sciences(all)