CCS and Power Systems
Carbon Storage - Geologic Storage Technologies and Simulation and Risk Assessment
Area 1: Influence of Local Capillary Trapping on Containment System Effectiveness
Performer: University of Texas at Austin
Project No: FE0004956
Program Background and Project Benefits
The overall goal of the Department of Energy’s (DOE) Carbon Storage Program is to develop and advance technologies that will significantly improve the effectiveness of geologic carbon storage, reduce the cost of implementation, and prepare for widespread commercial deployment between 2020 and 2030. Research conducted to develop these technologies will ensure safe and permanent storage of carbon dioxide (CO2) to reduce greenhouse gas (GHG) emissions without adversely affecting energy use or hindering economic growth.
Geologic carbon storage involves the injection of CO2 into underground formations that have the ability to securely contain the CO2 permanently. Technologies being developed for geologic carbon storage are focused on five storage types: oil and gas reservoirs, saline formations, unmineable coal seams, basalts, and organic-rich shales. Technologies being developed will work towards meeting carbon storage programmatic goals of (1) estimating CO2 storage capacity +/- 30 percent in geologic formations; (2) ensuring 99 percent storage permanence; (3) improving efficiency of storage operations; and (4) developing Best Practices Manuals. These technologies will lead to future CO2 management for coal-based electric power generating facilities and other industrial ization of CO2 in all storage types. CO2 emitters by enabling the storage and utilization of CO2 in all storage types.
The DOE Carbon Storage Program encompasses five Technology Areas: (1) Geologic Storage and Simulation and Risk Assessment (GSRA), (2) Monitoring, Verification, Accounting (MVA) and Assessment, (3) CO2 Use and Re-Use, (4) Regional Carbon Sequestration Partnerships (RCSP), and (5) Focus Area for Sequestration Science. The first three Technology Areas comprise the Core Research and Development (R&D) that includes studies ranging from applied laboratory to pilot-scale research focused on developing new technologies and systems for GHG mitigation through carbon storage. This project is part of the Core R&D GSRA Technology Area and works to develop technologies and simulation tools to ensure secure geologic storage of CO2. It is critical that these technologies are available to aid in characterizing geologic formations before CO2-injection takes place in order to predict the CO2 storage resource and develop CO2 injection techniques that achieve optimal use of the pore space in the reservoir and avoid fracturing the confining zone (caprock). The program’s R&D strategy includes adapting and applying existing technologies that can be utilized in the next five years, while concurrently developing innovative and advanced technologies that will be deployed in the decade beyond. For this project, researchers are conducting computer simulations and laboratory experiments to establish the feasibility of a new technique for assessing capillary trapping in geologic formations.
The proposed simulation and experiments will systematically establish proof-of-feasibility of a novel concept, namely the long-term security of CO2 that fills local (small-scale) capillary traps in heterogeneous storage formations. The outcome will be a geologically grounded method for quantifying the extent of such trapping. The method can be implemented with simulation capabilities already being used to predict storage security. The impact will be a potential reduction in risks associated with long-term storage security, achieved simply by considering the physical implications of geologic heterogeneity. This research supports the Carbon Storage Programmatic goal of demonstrating 99 percent storage permanence.
The overall goal of this project is to obtain a high-quality assessment of the amount and extent of local capillary trapping expected to occur in typical geologic storage formations. The goal is being accomplished by addressing several key project objectives that include: (1) quantifying the influence of key geologic and petrophysical parameters on the structure of local capillary barriers in a heterogeneous formation, and hence on the potential number and volume of local capillary traps; (2) determining what fraction of these traps is filled during prototypical CO2 emplacement operations (injection followed by buoyancy-driven migration) by simulation and laboratory experimentation; and (3) simulation and experimentation to quantify what fraction of the filled local capillary traps retains CO2 if the top seal of the storage formation loses integrity and allows CO2 to leak. In order to complete the overall project objectives, researchers will conduct the following research efforts:
Characterizing petrophysical and geologic controls on the number and volume of potential local capillary traps.
Determining the degree to which potential local capillary traps are filled in anticipated geologic storage schemes.
Quantifying the extent of immobilization persisting after loss of integrity of the seal overlying the geologic storage formation.
Incorporating the results into a functional form which can be easily integrated into existing reservoir simulation packages.
Conducting lab-scale experiments to validate simulation modeling.