Grantee Research Project Results
2012 Progress Report: A Hierarchical Modeling Framework for Geological Storage of Carbon Dioxide
EPA Grant Number: R834385Title: A Hierarchical Modeling Framework for Geological Storage of Carbon Dioxide
Investigators: Celia, Michael A.
Institution: Princeton University
EPA Project Officer: Aja, Hayley
Project Period: December 1, 2009 through November 30, 2013
Project Period Covered by this Report: December 1, 2011 through November 30,2012
Project Amount: $870,009
RFA: Integrated Design, Modeling, and Monitoring of Geologic Sequestration of Anthropogenic Carbon Dioxide to Safeguard Sources of Drinking Water (2009) RFA Text | Recipients Lists
Research Category: Drinking Water , Water
Objective:
The project has four general goals and objectives: (1) to develop and enhance a set of analytical and numerical computational tools for simulation of CO2 injection, migration, and possible leakage; (2) to develop a ‘hierarchical modeling framework’ within which different computational tools can be combined to produce effective hybrid models; (3) to provide guidance on level of model complexity for different scenarios; and (4) to provide simple-to-use web-based interfaces for different versions of the codes we develop. During the third year of the project, we have made progress on all four of these objectives.
Progress Summary:
Objectives 1 and 2:
We continue to expand our "simplified" models to include additional processes. In 2012, we published a paper (Gasda, et al., 2012) in which we moved away from the assumption of a sharp interface separating the CO2 and brine and allowed a finite-thickness capillary transition zone. When coupled with our earlier inclusion of large-scale dissolution, enhanced by convective mixing (Gasda, et al., 2011), our current model includes all significant physical processes, with the only major assumption being vertical equilibrium. The example calculations in Gasda, et al. (2012) show the relative importance of large-scale two-phase flow of CO2 and brine, residual (capillary) trapping of CO2, dissolution trapping of CO2, and the impacts of a non-zero capillary transition zone. These results allow us to quantify the “storage security” as a function of time, because the model tracks the fractions of injected CO2 mass held in the reservoir by structural trapping, capillary trapping, and dissolution trapping (see Figures 9 and 10 in Gasda, et al., 2012).
We also continued our work on leakage potential with a focus on leakage along old wells. In Nogues, et al. (2012), we developed practical guidance for how well leakage might be analyzed when specific maximum leakage targets are identified. The results in that paper showed what kinds of statistics the effective permeability along old wells must satisfy in order to meet target leakage criteria. We also have continued to develop our local-scale solution for leakage along fault zones, although this problem has turned out to be much more challenging than expected. We now have both analytical solutions and a number of detailed numerical solutions that we are comparing to understand the leakage behavior along faults and fractures. Finally, we have begun to develop “simplified” models that remove the assumption of vertical equilibrium (VE), while still maintaining the reduction of dimensionality that allows for computational simplifications in the VE models. This is described below in the “New Areas of Study” section.
Objective 3:
The paper of Court, et al. (2012a) analyzes the conditions under which we can reasonably assume vertical equilibrium (VE) as well as a macroscopic sharp interface. The VE assumption requires that the time required for the two fluids to segregate by buoyancy is small relative to the simulation times. This criterion depends on density differences, vertical permeability, and some details of the multi-phase fluid properties. The assumption of a sharp interface depends strongly on the functional form of the local capillary pressure function. Both of these assumptions, and the associated requirements for them to be valid, are explained in detail in the paper. The results of this analysis led us to develop methods that would allow both of these assumptions to be relaxed without losing computational efficiencies. We believe this will fill in a major gap in the complexity spectrum for CO2 modeling, while answering criticisms of the vertical equilibrium assumption.
We also published two papers (Bandilla, et al., 2012, 2013) in which we examined the large-scale impacts of basin-wide injections into the Mt Simon aquifer. The extensive overlap of the Areas of Review led to exploration of brine production as a method of pressure control. This subsequently led us to consider the CCUS (carbon capture, utilization, and storage) more broadly, which has led to some new explorations looking at potential synergies between geothermal energy production and CO2 injection – see, for example, Elliot et al. (2013).
Objective 4:
We continue to offer a publically available web interface where simple calculations for CO2 plume evolution, pressure response, and potential leakage along an old well can be investigated. We are in the process of updating and improving the website and hope to have those improvements implemented by the end of the current year of the project. The two senior researchers on the project, Prof. Celia and Dr. Bandilla, attended the EPA STAR workshop in Washington, D.C., in January 2013 to present the progress on our project and to interact with other PIs as well as EPA personnel. Among other things, this led to productive discussions about how our approaches to CO2 modeling might be useful to analyze practical questions about fracking and shale gas, especially questions related to leakage of gas and fracking fluids.
New Areas of Study:
One of the major advantages of the vertical equilibrium assumption is the associated integration, in the vertical direction, of the governing three-dimensional equations. This leads to two-dimensional equations that are significantly easier to solve. Based on our observations about the limitations of the VE assumption, we now have begun to develop new algorithms that will allow us to maintain the simplifications and efficiencies associated with vertical integration of the governing equations while allowing the VE assumption to be relaxed or eliminated. The idea is based on our development of the VE equations in a multi-scale framework, which led us to think about the vertical profile of pressure and saturation as a so-called reconstruction operator. Within this framework, we now are developing dynamic reconstruction operators that allow for vertical dynamics in the system while maintaining the overall integrated structure of the equations. Initial tests have been promising, but we still have significant work to do to understand the behavior of the algorithm and to identify its limitations.
We also have begun to interact with EPA personnel on issues associated with fracking and production of unconventional oil and gas, with a focus on how our models might be useful to investigate specific questions about leakage. Members of our research group plan to attend an EPA workshop in Research Triangle Park, NC, in April 2013, where the topics for discussion will include potential leakage of fluids along wellbores. We will investigate how our CO2 models may be useful for problems associated with unconventional oil and gas.
Significance of Results to Date:
A summary of results has been provided in this annual report. Here we highlight the most significant accomplishments to date on this project: (1) We now have a simplified vertical equilibrium model that can simulate multi-phase flows, dissolution including convective mixing, capillary trapping, and leakage. Application to realistic injection sites shows its utility.
(2) We have identified conditions under which the assumption of vertical equilibrium is appropriate, based on time-scale analysis. We also have identified the conditions under which the sharp-interface assumption is appropriate, based on length-scale analysis associated with the capillary transition zone. We also have shown that when these assumptions are valid, there is excellent match between our models and full three-dimensional models like the industry standard Eclipse.
(3) We have expanded our studies to include active management of brine in injection formations, motivated in part by the need to control pressure buildup in the formation. Corollary benefits include reduction in potential leakage for both CO2 and brine, and possible surface use of water and/or heat associated with the extracted brine.
(4) We have developed a first algorithm that uses the vertically integrated equations associated with vertical equilibrium but relaxes the actual assumption of vertical equilibrium. This is based on the idea of dynamic reconstruction, in the context of a multi-scale framework for the governing equations in the CO2 system. This method is promising but requires further testing. If successful, it will fill a significant gap in the spectrum of model complexity, between VE models and traditional full three-dimensional simulators.
(5) We have begun to investigate how our models for CO2 migration and leakage might be applied to issues associated with hydraulic fracturing and unconventional oil and gas production. This is motivated by discussions we have had with EPA personnel, beginning with the EPA workshop in Washington, D.C., held in January 2013.
Future Activities:
We will continue to work on all four objectives, with the overall objective being completion of the project at the end of the no-cost extension period and within the project budget. We also will continue to pursue new and interesting directions as they arise, including the recently initiated discussions with EPA personnel about how our approaches for CO2 modeling might be used to help answer important questions about leakage associated with fracking and unconventional gas and oil development. We also will continue to publish our research results in appropriate journals and to present our work at national and international conferences.
Journal Articles on this Report : 11 Displayed | Download in RIS Format
| Other project views: | All 25 publications | 18 publications in selected types | All 18 journal articles |
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Bandilla KW, Celia MA, Elliot TR, Person M, Ellet KM, Rupp JA, Gable C, Zhang Y. Modeling carbon sequestration in the Illinois Basin using a vertically-integrated approach. Computing and Visualization in Science 2012;15(1):39-51. |
R834385 (2012) R834385 (Final) |
Exit |
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Buscheck TA, Sun YW, Chen MJ, Hao Y, Wolery TJ, Bourcier WL, Court B, Celia MA, Friedmann SJ, Aines RD. Active CO2 reservoir management for carbon storage: analysis of operational strategies to relieve pressure buildup and improve injectivity. International Journal of Greenhouse Gas Control 2012;6:230-245. |
R834385 (2011) R834385 (2012) R834385 (Final) |
Exit Exit Exit |
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Celia MA, Nordbotten JM, Court B, Dobossy M, Bachu S. Field-scale application of a semi-analytical model for estimation of CO2 and brine leakage along old wells. International Journal of Greenhouse Gas Control 2011;5(2):257-269. |
R834385 (2010) R834385 (2011) R834385 (2012) R834385 (Final) |
Exit Exit Exit |
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Court B, Elliot TR, Dammel JA, Buscheck TA, Rohmer J, Celia MA. Promising synergies to address water, sequestration, legal, and public acceptance issues associated with large-scale implementation of CO2 sequestration. Mitigation and Adaptation Strategies for Global Change 2012;17(6):569-599. |
R834385 (2012) R834385 (Final) |
Exit Exit |
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Court B, Bandilla KW, Celia MA, Buscheck TA, Nordbotten JM, Dobossy M, Janzen A. Initial evaluation of advantageous synergies associated with simultaneous brine production and CO2 geological sequestration. International Journal of Greenhouse Gas Control 2012;8:90-100. |
R834385 (2011) R834385 (2012) R834385 (Final) |
Exit Exit Exit Exit |
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Court B, Bandilla KW, Celia MA, Janzen A, Dobossy M, Nordbotten JM. Applicability of vertical‐equilibrium and sharp‐interface assumptions in CO2 sequestration modeling. International Journal of Greenhouse Gas Control 2012;10:134-147. |
R834385 (2011) R834385 (2012) R834385 (Final) |
Exit Exit Exit Exit |
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Elliot TR, Celia MA. Potential restrictions for CO2 sequestration sites due to shale and tight gas production. Environmental Science & Technology 2012;46(7):4223-4227. |
R834385 (2011) R834385 (2012) R834385 (Final) |
Exit Exit |
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Elliot TR, Buscheck TA, Celia M. Active CO2 reservoir management for sustainable geothermal energy extraction and reduced leakage. Greenhouse Gases: Science and Technology 2013;3(1):50-65. |
R834385 (2012) R834385 (Final) |
Exit Exit |
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Gasda SE, Nordbotten JM, Celia MA. Vertically-averaged approaches for CO2 migration with solubility trapping. Water Resources Research 2011;47(5):W05528. |
R834385 (2010) R834385 (2011) R834385 (2012) R834385 (Final) |
Exit Exit Exit Exit |
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Gasda SE, Nordbotten JM, Celia MA. Application of simplified models to CO2 migration and immobilization in large-scale geological systems. International Journal of Greenhouse Gas Control 2012;9:72-84. |
R834385 (2011) R834385 (2012) R834385 (Final) |
Exit Exit Exit |
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Nogues JP, Court B, Dobossy M, Nordbotten JM, Celia MA. A methodology to estimate maximum probable leakage along old wells in a geological sequestration operation. International Journal of Greenhouse Gas Control 2012;7:39-47. |
R834385 (2011) R834385 (2012) R834385 (Final) |
Exit Exit |
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.