||Evaluation of Effective Thickness of Shale Layers of Multi-layer Caprock System
||Department of Resources Engineering
Multilayered caprock system
Frontal advance equation at constant pressure difference
Safety index plot
為了要減少在大氣中的二氧化碳濃度，有學者提出碳捕獲與封存(Carbon Capture and Storage,簡稱CCS)。對於減緩二氧化碳排放到大氣中，CCS是目前被視為最具潛力的方法。其中地質封存為目前最可行的方法之一，另外飽含鹽水層也被視為最具有封存潛力的儲氣場址。過去，地質封存中的蓋岩層是指位於儲氣窖上方的地層，其特性具有極低滲透率且緻密。單一且很厚的頁岩層常被視為蓋岩層的最好選擇。然而，事實上有很多頁岩層是常常夾帶具滲透的地層，具滲透性的地層像是頁質砂岩或者粉沙，這代表這些地層是由頁岩與其他岩性所組成。本研究稱之為多層次蓋岩層系統。
Carbon capture and storage (CCS) is considered a promising method of mitigating CO2 emissions into the atmosphere. Geological storage is the most feasible way to permanently store CO2. Saline aquifers are thought to have the greatest storage capacity of all geological storage sites. In the past, a caprock with extremely - low permeability and dense stacking was a typical feature above a sealable geological storage reservoir. A single and thick shale layer was usually considered the best option for caprock. However, there are many types of shale layers that are usually interbedded with permeable layers, such as shaly-sand and silt. This means that these formations are composed of shale and other lithology. This is called a multilayered caprock system in this study.
Except for shale with extremely - low permeability, the permeable layers can provide efficient sealing. Thus, the purpose of this study was to investigate the sealing efficiency of a multilayered caprock system. Because a multilayered caprock system is shale interbedded with permeable layers, the system’s sealing efficiency is calculated as the sum of the sealing efficiency of each layer. In this study, caprock thickness and ScCO2 (supercritical CO2) plume breakthrough time at the caprock are parameters, that affect sealing efficiency. The ScCO2 plume breakthrough time of was calculated using an analytical method derived in this study.
The analytical method used was the frontal advance equation at constant pressure difference derived from Buckley-Leverett theory in this study. Because the ScCO2 plume accumulates beyond the caprock and thus concentrates the pressure, when the ScCO2 plume pressure is larger than the threshold pressure at the caprock formation, the ScCO2 plume will invade the caprock. Therefore, the frontal advance equation at a constant pressure difference was derived and then initially applied to ScCO2 migration at the caprock. In addition, Computer Modelling Group Ltd.’s (CMG) - GEM compositional simulator (CMG-GEM) was used to verify the correction of the analytical solution mentioned above. Two fundamental models (horizontal and vertical) were built to validate the analytical solution for ScCO2-water two-phase flow, respectively. . After the solution had been validated, we proposed a safety index plot derived from the analytical solution. This plot is convenient for determining the sealing efficiency at the caprock. Finally, we applied the analytical solution and safety index plot in a field case to observe and discuss the results.
We found that our analytical solution could be used to calculate the correct ScCO2 plume breakthrough time at the caprock. Moreover, our proposed safety index plot can be considered a graphical solution, the thickness of the caprock and the ScCO2 breakthrough time can be derived from this plot, and then the sealing efficiency at the caprock can be determined.
List of Tables VIII
List of Figures X
Chapter 1 Introduction 1
1-1 Background 1
1-2 Motivation 3
1-3 Purpose 4
Chapter 2 Literature review 5
2-1 Two phases fluid frontal advance equation 5
2-2 Multilayered caprock system 7
2-3 CO2 leakage evaluation 7
Chapter 3 Methods 11
3-1 Flooding behavior 12
3-2 Fraction flow equation 13
3-3 Frontal advance equation at a constant pressure difference 17
3-4 Breakthrough time equation 22
Chapter 4 Study process 25
Chapter 5 Building and validating a numerical model 28
5-1 Two-phase ScCO2-water fluid flow in a horizontal model 29
5-2 ScCO2-water two-phase fluid flow in a vertical model 34
Chapter 6 Results 42
Chapter 7 Discussion 46
7-1 Using the safety index plot in a single layer 46
7-2 Using the safety index plot in a multilayered caprock system 49
7-3 Using the safety index plot in case study 55
7-4 Match of saturation profile 66
Chapter 8 Conclusions and Suggestions 69
8-1 Conclusions 69
8-2 Suggestions 69
Appendix A: Derivation of Buckley-Leverett theory 76
A-1 Buckley-Leverett Theory 76
A-2 Fractional-flow Equation 78
Appendix B: Validating the Buckley-Leverett model 81
B-1 Water-oil model at a constant injection rate 81
B-2 ScCO2-water model in a constant injection rate 86
B-3 Water-oil model at a constant pressure difference 91
Appendix C: Development of safety index plot 97
1.Akaku, K. 2008. Numerical simulation of CO2 storage in aquifers without trapping structures. In International Petroleum Technology Conference. International Petroleum Technology Conference.
2.Arabzai, A., and S. Honma. 2013. Numerical simulation of the Buckley-Leverett problem. Proc. School of Eng. Of Tokai Univ, Vol 38, pp. 9-14.
3.Bachu, S. 2008. CO2 storage in geological media: Role, means, status and barriers to deployment. Progress in Energy and Combustion Science, Vol 34, pp. 254-273.
4.Bennion, B., and S. Bachu. 2005. Relative permeability characteristics for supercritical CO2 displacing water in a variety of potential sequestration zones. In SPE Annual Technical Conference and Exhibition. Society of Petroleum Engineers.
5.Benson, S. M., and D. R. Cole. 2008. CO2 Sequestration in Deep Sedimentary Formations. Elements, Vol 4, pp. 325-331.
6.Bickle, M. J. 2009. Geological carbon storage. Nature geoscience, Vol 2.
7.Birkholzer, J., Q. Zhou, and C. Tsang. 2009. Large-scale impact of CO2 storage in deep saline aquifers: A sensitivity study on pressure response in stratified systems. International Journal of Greenhouse Gas Control, Vol 3, pp. 181-194.
8.Brooks, R. H., and A. T. Corey. 1964. Hydraulic properties of porous media. Hydrology Papers, No. 3, Colorado State University, Ft, Collins, Colo.
9.Buckley, Se E, and MCi Leverett. 1942. Mechanism of fluid displacement in sands. Transactions of the AIME, Vol 146, pp. 107-116.
10.Burton, M., N. Kumar, and S. L. Bryant. 2009. CO2 injectivity into brine aquifers: Why relative permeability matters as much as absolute permeability. Energy Procedia, Vol 1, pp. 3091-3098.
11.Corey, A. T. 1954. The interrelation between gas and oil relative permeabilities, Producers monthly, Vol 19, pp. 38-41.
12.Corey, A. T., and C. H. Rathjens. 1956. Effect of stratification on relative permeability, Journal of Petroleum Technology, Vol 8, pp. 69-71.
13.Court, B., K. W. Bandilla, M. A. Celia, A. Janzen, M. Dobossy, and J. M. Nordbotten. 2012. Applicability of vertical-equilibrium and sharp-interface assumptions in CO2 sequestration modeling. International Journal of Greenhouse Gas Control, Vol 10, pp. 134-47.
14.CMG. 2015. User’s guide GEM. Advanced compositional reservoir simulator (version 2015). Computer Modeling Group Ltd: Calgary, Canada.
15.Dempsey, D., S. Kelkar, R. Pawar, E. Keating, and D. Coblentz. 2014. Modeling caprock bending stresses and their potential for induced seismicity during CO2 injection, International Journal of Greenhouse Gas Control, Vol 22, pp. 223-236.
16.Doughty, C. 2010. Investigation of CO2 plume behavior for a large-scale pilot test of geologic carbon storage in a saline formation. Transport in Porous Media, Vol 82, pp. 49-76.
17.Flett, M., R. Gurton, and I. Taggart. 2005. Heterogeneous saline formationsLong-term benefits for geo-sequestration of greenhouse gases. Proceedings of the 7th international conference on greenhouse gas control technologies (GHGT-7), Vol I, pp. 501-509.
18.Garcia, J. E., and K. Pruess. 2003. Flow instabilities during injection of CO2 into saline aquifers, Lawrence Berkeley National Laboratory.
19.Ghanbarnezhad M. R. 2012. A Graphical Solution To Model the Flow of Compressible CO2 in Aquifers. In Carbon Management Technology Conference. Carbon Management Technology Conference.
20.Chiao, C. H., 2015. Welling research and Core sample observation in storage site at West Taiwan Basin, Taiwan Power Company (in chinese).
21.Chiu, C. H., 2013. CO2 Plume Migration During and After Geological Sequestration in Saline Aquifer, National Cheng Kung University Master Degree Thesis (in chinese).
22.Gibson-Poole, C. M., L. Svendsen, J. Underschultz, M. N. Watson, J. Ennis-King, P. J. van Ruth, E. J. Nelson, R. F. Daniel, and Y. Cinar. 2007. Site characterisation of a basin-scale CO2 geological storage system: Gippsland Basin, southeast Australia. Environmental Geology, Vol 54, pp. 1583-1606.
23.Golding, M. J., J. A. Neufeld, M. A. Hesse, and H. E. Huppert. 2011. Two-phase gravity currents in porous media. Journal of Fluid Mechanics. Vol 678, pp. 248-270.
24.Hayek, M., E. Mouche, and C. Mügler. 2009. Modeling vertical stratification of CO2 injected into a deep layered aquifer, Advances in Water Resources, Vol 32, pp. 450-462.
25.Heath, J. E., T. A. Dewers, B. J. McPherson, M. B. Nemer, and P. G. Kotula. 2012. Pore-lining phases and capillary breakthrough pressure of mudstone caprocks: Sealing efficiency of geologic CO2 storage sites. International Journal of Greenhouse Gas Control, Vol 11, pp. 204-220.
26.Hesse, M. A., and A. W. Woods. 2010. Buoyant dispersal of CO2 during geological storage. Geophysical Research Letters, Vol 37.
27.Hepple, R. P., and S. M. Benson. 2004. Geologic storage of carbon dioxide as a climate change mitigation strategy: performance requirements and the implications of surface seepage, Environmental Geology, Vol 47, pp. 576-585.
28.Hou, Z., M. L Rockhold, and C. J. Murray. 2012. Evaluating the impact of caprock and reservoir properties on potential risk of CO2 leakage after injection. Environmental Earth Sciences, Vol 66: pp. 2403-2415.
29.Hovanessian, S. A., and F. J. Fayers. 1961. Linear water flood with gravity and capillary effects, Society of Petroleum Engineers Journal, Vol 1, pp. 32-36.
30.Hovorka, S. D., C. Doughty, S. M. Benson, K. Pruess, and P. R. Knox. 2004. The impact of geological heterogeneity on CO2 storage in brine formations: a case study from the Texas Gulf Coast. Geological Society, London, Special Publications, Vol 233, pp. 147-163.
31.Hsieh, B. Z., L. Nghiem, C. H. Shen, and Z. S. Lin. 2013. Effects of complex sandstone–shale sequences of a storage formation on the risk of CO2 leakage: Case study from Taiwan. International Journal of Greenhouse Gas Control, Vol 17, pp. 376-387.
32.IPCC. 2005. Carbon dioxide capture and storage: special report of the intergovernmental panel on climate change (Cambridge University Press).
33.Kaldi, J., R. Daniel, E. Tenthorey, K. Michael, Ulrike Schacht, Andy Nicol, Jim Underschultz, and Guillaume Backe. 2013. Containment of CO2 in CCS: Role of Caprocks and Faults. Energy Procedia, Vol 37: pp. 5403-5410.
34.Karimnezhad, M., H. Jalalifar, and M. Kamari. 2014. Investigation of caprock integrity for CO2 sequestration in an oil reservoir using a numerical method, Journal of Natural Gas Science and Engineering, Vol 21, 1127-1137.
35.Kumar, A., M. H. Noh, R. C. Ozah, G. A. Pope, S. L. Bryant, K. Sepehrnoori, and L. W. Lake. 2005. Reservoir simulation of CO2 storage in aquifers, Spe Journal, Vol 10, pp.336-348.
36.Leverett, M. C. 1941. Capillary behavior in porous solids, Transactions of the AIME, Vol 142, pp. 152-169.
37.Li, Y. H., Shen, C. H., Hsieh, B. Z., Yu, C. W. and Chiao, C. H., Application of welling analysis technique on choice of storage place in storage system at Changhua, Chinese Institute of Engineers, Vol. 90, No.2. pp. 37-49 (in chinese).
38.Liu, F., K. Ellett, Y. Xiao, and J. A. Rupp. 2013. Assessing the feasibility of CO2 storage in the New Albany Shale (Devonian–Mississippian) with potential enhanced gas recovery using reservoir simulation, International Journal of Greenhouse Gas Control, Vol 17, pp. 111-126.
39.Lu, C., Y. Sun, T. A. Buscheck, Y. Hao, J. A. White, and L. Chiaramonte. 2012. Uncertainty quantification of CO2 leakage through a fault with multiphase and nonisothermal effects. Greenhouse Gases: Science and Technology, Vol 2, pp. 445-459.
40.McEwen, C. R. 1959. A numerical solution of the linear displacement equation with capillary pressure. Journal of Petroleum Technology, Vol 11, pp. 45-48.
41.McMillan, B., N. Kumar, and S. L. Bryant. 2008. Time-dependent injectivity during CO2 storage in aquifers. In SPE Symposium on Improved Oil Recovery. Society of Petroleum Engineers.
42.NETL and DOE. 2015. Carbon Storage ATLAS Fifth Edition.
43.Nghiem, L, V. Shrivastava, B. Kohse, M. Hassam, and C. Yang. 2009. Simulation of trapping processes for CO2 storage in saline aquifers." In Canadian International Petroleum Conference. Petroleum Society of Canada.
44.Nghiem, L., V. Shrivastava, B. Kohse, M. Hassam, and C. Yang. 2010. Simulation and optimization of trapping processes for CO2 storage in saline aquifers, Journal of Canadian Petroleum Technology, Vol 49, pp. 15-22.
45.Nghiem, L., V. Shrivastava, D. Tran, B. Kohse, M. Hassam, and C. Yang. 2009. Simulation of CO2 storage in saline aquifers. In SPE/EAGE Reservoir Characterization & Simulation Conference.
46.Noh, M., L. W. Lake, S. L. Bryant, and A. A. Martinez. 2004. Implications of coupling fractional flow and geochemistry for CO2 injection in aquifers. In SPE/DOE Symposium on Improved Oil Recovery. Society of Petroleum Engineers.
47.Nordbotten, J. Martin, M. A. Celia, and S. Bachu. 2005. Injection and Storage of CO2 in Deep Saline Aquifers: Analytical Solution for CO2 Plume Evolution During Injection, Transport in Porous Media, Vol 58, pp. 339-360.
48.Owusu, P. A., L. DeHua, and R. D. Nagre. 2014. Buckley-Leverett displacement theory for waterflooding performance in stratified reservoir, Petroleum & Coal, Vol 56, pp. 267-281.
49.Rezaeyan, Amirsaman, S. A. Tabatabaei-Nejad, E. Khodapanah, and M. Kamari. 2015. A laboratory study on capillary sealing efficiency of Iranian shale and anhydrite caprocks. Marine and Petroleum Geology, Vol 66: pp. 817-828.
50.Saadatpoor, E., S. L. Bryant, and K. Sepehrnoori. 2010. CO2 Leakage from Heterogeneous Storage Formations. In SPE Annual Technical Conference and Exhibition. Society of Petroleum Engineers.
51.Shukla, R., P. G. Ranjith, S. K. Choi, and A. Haque. 2011. Study of Caprock Integrity in Geosequestration of Carbon Dioxide, International Journal of Geomechanics, Vol 11, pp. 294-301.
52.Taiwan Power Company, 2014. Final report of geological investment and technology in Carbon dioxide geological storage development at experiment site (in chinese).
53.Tian, H., T. Xu, Y. Li, Z. Yang, and F. Wang. 2015. Evolution of sealing efficiency for CO2 geological storage due to mineral alteration within a hydrogeologically heterogeneous caprock. Applied Geochemistry, Vol 63, pp. 380-397.
54.Vilarrasa, V. 2014. Impact of CO2 injection through horizontal and vertical wells on the caprock mechanical stability, International Journal of Rock Mechanics and Mining Sciences, Vol 66, pp. 151-159.
55.Walsh, M. P., and G. M. Moon. 1991. An analysis of gravity-dominated, immiscible flows in dipping reservoirs. In SPE Production Operations Symposium. Society of Petroleum Engineers.
56.Wang, J. G., Y. Ju, F. Gao, Y. Peng, and Y. Gao. 2015. Effect of CO 2 sorption-induced anisotropic swelling on caprock sealing efficiency. Journal of Cleaner Production, Vol 103, pp. 685-695.
57.Wang, J. G., and Y. Peng. 2014. Numerical modeling for the combined effects of two-phase flow, deformation, gas diffusion and CO 2 sorption on caprock sealing efficiency. Journal of Geochemical Exploration, Vol 144, pp. 154-167.
58.Wang, J. G., Y. Ju, F. Gao, and J. Liu. 2016. A simple approach for the estimation of CO2 penetration depth into a caprock layer, Journal of Rock Mechanics and Geotechnical Engineering, Vol 8, pp. 75-86.
59.Welge, H. J. 1952. A simplified method for computing oil recovery by gas or water drive, Journal of Petroleum Technology, Vol 4, pp. 91-98.
60.Willhite, G. P. 1986. Waterflooding (Spe Textbook Series) (Society of Petroleum Engineers).
61.Wriedt, J., M. Deo, W. S. Han, and J. Lepinski. 2014. A methodology for quantifying risk and likelihood of failure for carbon dioxide injection into deep saline reservoirs, International Journal of Greenhouse Gas Control, Vol 20, pp. 196-211.
62.Wu, Y. S., K. Pruess, and Z. X. Chen. 1993. Buckley-Leverett flow in composite porous media, SPE Advanced Technology Series, Vol 1, pp. 36-42.
63.Yortsos, Y. C., and A. S. Fokas. 1983. An analytical solution for linear waterflood including the effects of capillary pressure, Society of Petroleum Engineers Journal, Vol 23, pp. 115-124.
64.Zhao, R., J. Cheng, and K. Zhang. 2012. CO2 plume evolution and pressure buildup of large-scale CO2 injection into saline aquifers in Sanzhao Depression, Songliao Basin, China. Transport in Porous Media, pp. 1-18.