CCS and Power Systems
Carbon Storage - Geologic Storage Technologies and Simulation and Risk Assessment
Maximization of Permanent Trapping of CO2 and Co-Contaminants in the Highest-Porosity Formations of
Performer: University of Wyoming
Project No: FE0004832
The University of Wyoming (UW) is using a combination of past and current research results to further investigate the most promising target for geologic storage of CO2 in the state of Wyoming, the Rock Springs Uplift (RSU). Within the RSU are saline formations, which are the focus of this study. Saline formations are deep sedimentary rock formations that contain brine (groundwater that is not considered potable because it contains more than 10,000 parts per million total dissolved solids) in pore spaces. Saline formations suitable for geologic storage of CO2 are typically overlain by low-permeability rock that prevents upward movement of CO2 by effectively sealing the top of the saline formation. Saline formations are promising geologic storage formations because they are quite extensive throughout North America and represent an enormous potential for CO2 geologic storage. However, due to the lack of characterization data for saline-bearing formations, relatively little is known about them when compared to oil and gas reservoirs and coal seams. Therefore, there is a greater amount of uncertainty regarding the suitability of saline formations for CO2 storage.
The project includes experimental and numerical modeling of the carbon storage process to aid in understanding the migration and storage mechanisms related to injecting mixed supercritical CO2 (mixed scCO2) into the RSU’s saline formations. Mixed scCO2 is CO2 that contains small amounts of other chemicals (sulfur compounds, nitrogen oxides, and hydrochloric acid) and exists at temperatures and pressures that give it the properties of both a gas and liquid. Capturing and storing mixed scCO2 is beneficial because the CO2 stream does not need additional purification to remove co-contaminants, which saves energy and reduces overall costs. The investigation will combine reservoir-condition core flooding experimental studies (Figure 1), numerical pore- and storage formation-scale modeling, and high-performance computing to investigate various large-scale storage schemes with the goal of understanding the permanent trapping characteristics for maximizing CO2 storage in saline formations. The results of the investiga tion are being used to inform reservoir-scale simulations utilizing detailed and realistic geologic models of RSU formations in order to identify schemes that maximize permanent trapping of mixed scCO2 released from Wyoming coal power plants. An existing and unique experimental facility will be used to perform core flooding experiments (Figure 2). The chemical and physical characteristics of injected mixed scCO2 must be understood in order to maximize CO2 storage in saline formations.