Kyung Won Chang
Ph.D., Earth science, The University of Texas at Austin, expected 2013
- Computational Geosciences
Kyung Won aims to understand the dynamics of multiphase flow in geological porous media. He started his academic career with engineering minds, a BS in geotechnical engineering and a MS in petroleum engineering. He is continuing his ph.D in geological sciences. Kyung Won believes that his multidiscipline background will allow him be a smart bridge between geo-engineers and geo-scientists.
Graduate Research Grant
- Geological Society of America (GSA) (2012)
Ronald K. DeFord Field Scholarship
- The University of Texas at Austin (2012)
- The University of Texas at Austin (2010)
Graduate Research Grant
- American Association of Petroleum Geologists (AAPG) (2010)
- The University of Texas at Austin (2005)
Overpressure dissipation into ambient mudrocks
The evaluation of the reservoir capacity for geological CO2 storage is essential for the site selection as well as the feasibility of the overall technology. Our study shows that small, but finite, permeability and high storativity of ambient mudrocks induce a significant dissipation of injection-induced overpressure into the mudrock. This significantly increases the storage capacity and reduces the radius of review. The variability in mudrock properties may cause large uncertainty in the estimate of the storage capacity and therefore the careful site characterization is required to reduce this uncertainty.
Exchange flow through porous media
A layered reservoir intersected by a conductive fault can have an exchange flow across the fault if the upper reservoir contains denser fluid. The large reservoir volume relative to the fault will allow a quasi-steady exchange flow across the fault before the fluid densities are equalized. We aim to quantify the exchange rate as a function of the fault properties and geometry and the fluid properties, and the type of fluid bypassing. Three limiting modes of such bypassing are possible: 1) countercurrent flows in quasi 1D fault, 2) fingering of fluids in 2D high-angle planar fault and 3) gravity segregation in 3D low-angle fault. Different types of fluid bypassing will give rise to large differences in exchange rates across the fault. In this experimental and numerical study we will quantify the quasi-steady exchange rate as a function of fault and fluid properties leading to a regime diagram that indicates the dominant dynamical regime controlling the exchange rate.
Effects of faults on CO2 plume dynamics
The injected CO2 in a target formation can continue to migrate through permeable pathways due to geological heterogeneity as well as buoyancy. This movement drives a countercurrent flow of brine leading to increased residual phase trapping. The purpose of this simulation study is to understand the effects of geological structures, especially faults, on the dynamic behavior of the buoyancy-driven CO2 plume and the amount of residual trapping. We studied the behavior of CO2 plumes (speed, direction, saturation at displacement front, residual phase trapping) in 2D and 3D formations with a range of fault properties (conductive vs. sealing, angle relative to dip, distance from initial plume location).
Before CO2 plumes enter the fault-influenced region of the aquifer, the reservoir properties determine the plume behavior. If the plume encounters a fault within the reservoir, the fault can create new virtual source (CO2 build-up at the plume/fault intersection) for migration. It also leads