Hydrogeological characterization of shallow-depth zone for CO2 injection and leak test at a CO2 environmental monitoring site in Korea

Abstract:

The main goal of the this study is to evaluate the importance of heterogeneities in controlling the field-scale transport of CO₂ are originated from the CO2 injected at saturated zone below the water table for monitoring and prediction of CO₂ leakage from a reservoir. Hydrogeological and geophysical data are collected to characterize the site, prior to conducting CO₂ injection experiment at the CO₂ environmental monitoring site at Eumseong, Korea. The geophysical data were acquired from borehole electromagnetic flowmeter tests, while the hydraulic data were obtained from pumping tests, slug tests, and falling head permeability tests. Total of 13 wells to perform hydraulic and geophysical test are established along groundwater flow direction in regular sequence, revealed by the results of borehole electromagnetic flowmeter test. The results of geophysical tests indicated that hydraulic gradient is not identical with the topographic gradient. Groundwater flows toward the uphill direction in the study area. Then, the hydraulic tests were conducted to identify the hydraulic properties of the study site. According to the results of pumping and slug tests at the study site, the hydraulic conductivity values show ranges between 4.75 x 10^-5 cm/day and 9.74 x 10^-5 cm/day. In addition, a portable multi-level sampling and monitoring packer device which remains inflated condition for a long period developed and used to isolate designated depths to identify vertical distribution of hydrogeological characteristics. Hydrogeological information obtained from this study will be used to decide the injection test interval of CO₂-infused water and gaseous CO₂.

Acknowledgement: Financial support was provided by "R&D Project on Environmental Mangement of Geologic CO₂ Storage" from the KEITI (Project Number: 2014001810003).