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2025 Vol.24, Issue 3 Preview Page

Research Article

Evaluation of Physical and Mechanical Properties of Synthetic Caprock Simulating the Mineral Composition of Caprock in Pohang and Janggi Basins, Korea

포항·장기분지 덮개암의 광물 조성을 모사한 인공 덮개암 제작 및 물리·역학적 특성 평가

Junyeong Seo1
,
Hangseok Choi2
,
Sangyeong Park3
,
Kiseok Kim4
,
Hyeontae Park5*
서 준영1
,
최 항석2
,
박 상영3
,
김 기석4
,
박 현태5*
1Non-Member, Master Course Student, Department of Civil, Environmental and Architectural Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
2Member, Professor, School of Civil, Environmental and Architectural Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
3Non-Member, Research Professor, Future and Fusion Lab of Architectural, Civil and Environmental Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
4Non-Member, Assistant Professor, Department of Petroleum Engineering, Texas A&M University, 400 Bizzell Street, College Station, Texas 77840, United States of America
5Member, Ph.D. Student, Department of Civil, Environmental and Architectural Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
*Corresponding Author
30 September 2025. pp. 27-38
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Abstract

In carbon capture and storage (CCS), maintaining caprock integrity is a critical factor for ensuring the long-term containment of CO2. Caprock integrity is typically assessed by analyzing the physical and mechanical properties of natural core samples obtained through drilling. However, due to the high costs associated with drilling and the risk of core damage, recent studies have increasingly explored the use of synthetic rock as an alternative. In this study, synthetic caprock samples were fabricated to replicate the mineral compositions of caprock from the Pohang and Janggi basins, which are considered potential CO2 storage sites in Korea. Porosity, permeability, and uniaxial compressive strength (UCS) were measured to evaluate the physical and mechanical behavior of the synthetic caprock under varying consolidation stress conditions. With increasing consolidation stress, porosity and permeability decreased, while UCS increased in both synthetic samples. However, notable differences in physical and mechanical properties were observed between the synthetic samples and natural rock, primarily due to the absence of chemical diagenetic processes, such as cementation and chemical compaction, in laboratory conditions. These findings provide essential baseline data for the fabrication of site-specific synthetic caprock analogs in CCS demonstration projects.

Keywords
Carbon capture and storage
Caprock
Synthetic rock
Laboratory experiment
Mineral composition

이산화탄소 지중저장(Carbon Capture and Storage, CCS) 기술에서 이산화탄소를 심부지층에 장기간 안전하게 저장하기 위해서는 덮개암의 건전성이 필수적으로 확보되어야 한다. 일반적으로 덮개암 건전성 평가는 시추를 통해 채취한 자연암석 코어의 물리·역학적 특성을 분석하여 수행된다. 그러나 시추 비용이 높고 시료 손상의 우려가 있어, 최근에는 인공암석을 활용한 연구가 활발히 이루어지고 있다. 본 연구에서는 국내 이산화탄소 지중저장소 후보지로 평가되는 포항분지와 장기분지 덮개암의 광물 조성을 바탕으로 인공 덮개암을 제작하였다. 또한, 압밀 하중에 따른 인공 덮개암의 물리·역학적 특성을 평가하기 위해 공극률과 투수계수, 일축압축강도를 측정하였다. 실험 결과, 압밀 하중이 증가함에 따라 포항분지 및 장기분지 시료 모두 공극률과 투수계수는 감소하고, 일축압축강도는 증가하는 경향을 보였다. 그러나 두 시료는 자연암석과 비교할 때 물리·역학적 특성에서 차이를 보였으며, 이는 교결작용 및 화학적 압축과 같은 화학적 속성 작용이 실험실 조건에서 재현되지 않았기 때문으로 판단된다. 본 연구의 결과는 향후 국내 이산화탄소 지중저장 실증 사업에서 부지 특성을 반영한 인공 덮개암 제작을 위한 기초 자료로 활용될 수 있을 것이다.

References
1

ASTM D4318, Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils.

2

ASTM D854, Standard Test Methods for Specific Gravity of Soil Solids by the Water Displacement Method.

3

Bai, M., Zhang, Z. and Fu, X. (2016), “A review on well integrity issues for CO2 geological storage and enhanced gas recovery”, Renewable and Sustainable Energy Reviews, Vol.59, pp.920-926.

10.1016/j.rser.2016.01.043
4

Beloborodov, R., Pervukhina, M. and Lebedev, M. (2018), “Compaction trends of full stiffness tensor and fluid permeability in artificial shales”, Geophysical Journal International, Vol.212, No.3, pp.1687-1693.

10.1093/gji/ggx510
5

Burland, J. B. (1990), “On the compressibility and shear strength of natural clays”, Géotechnique, Vol.40, No.3, pp. 329-378.

10.1680/geot.1990.40.3.329
6

Chae, S. Y. and Kwon, S. J. (2012), “A Study on Domestic Policy Framework for Application of Carbon Dioxide Capture and Storage(CCS)”, Journal of the Korean Society of Marine Environment & Safety, Vol.18, No.6, pp.617-625.

10.7837/kosomes.2012.18.6.617
7

Chen, B., Li, Q. and Tan, Y. (2025), “Caprock sealing for geologic CO2 storage: Research advances, challenges and prospects”, Journal of Rock Mechanics and Geotechnical Engineering, in press.

10.1016/j.jrmge.2025.02.006
8

Cui, G., Zhou, C., Liu, Z., Xia, C. and Zhang, L. (2022), “The synthesis of soft rocks based on physical and mechanical properties of red mudstone”, International Journal of Rock Mechanics and Mining Sciences, Vol.151, p.105037.

10.1016/j.ijrmms.2022.105037
9

Fawad, M., Mondol, N. H., Jahren, J. and Bjørlykke, K. (2010), “Microfabric and rock properties of experimentally compressed silt-clay mixtures”, Marine and Petroleum Geology, Vol.27, No.8, pp.1698-1712.

10.1016/j.marpetgeo.2009.10.002
10

Fedrizzi, R. M., de Ceia, M. A. R., Misságia, R. M., Santos, V. H. and Neto, I. L. (2018), “Artificial carbonate rocks: Synthesis and petrophysical characterization”, Journal of Petroleum Science and Engineering, Vol.163, pp.303-310.

10.1016/j.petrol.2017.12.089
11

Folger, P. F. (2018), “Carbon Capture and Sequestration (CCS) in the United States”, Congressional Research Service, pp.1-27.

12

Fu, H. Y., Qi, S. X., Shi, Z. N. and Zeng, L. (2021), “Mixing Ratios and Cementing Mechanism of Similar Silty Mudstone Materials for Model Tests”, Advances in Civil Engineering, Vol.2021, No.1, p.2426130.

10.1155/2021/2426130
13

Greig, C. and Uden, S. (2021), “The value of CCUS in transitions to net-zero emissions”, The Electricity Journal, Vol.34, No.7, p.107004.

10.1016/j.tej.2021.107004
14

Guiltinan, E. J., Espinoza, D. N., Cockrell, L. P. and Cardenas, M. B. (2018), “Textural and compositional controls on mudrock breakthrough pressure and permeability”, Advances in Water Resources, Vol.121, pp.162-172.

10.1016/j.advwatres.2018.08.014
15

He, W., Chen, K., Hayatdavoudi, A., Sawant, K. and Lomas, M. (2019), “Effects of clay content, cement and mineral composition characteristics on sandstone rock strength and deformability behaviors”, Journal of Petroleum Science and Engineering, Vol.176, pp.962-969.

10.1016/j.petrol.2019.02.016
16

Holt, R. M., Brignoli, M. and Kenter, C. J. (2000), “Core quality: quantification of coring-induced rock alteration”, International Journal of Rock Mechanics and Mining Sciences, Vol.37, No.6, pp.889-907.

10.1016/S1365-1609(00)00009-5
17

International Energy Agency (IEA) (2023), Net Zero Roadmap: A Global Pathway to Keep the 1.5℃ Goal in Reach, Paris, pp.1-224.

18

Jang, J. M., Kim, J. Y., Joeng, W. K., Choi, J., Jin, Y. S., Kang, K. S., Baek, W. J. and Lee, K. I. (2014), “A Study on the Consolidation Characteristics Using the Constant Strain Rate Test of Remolded Gwangyang Marine Clay”, Journal of the Korean Geosynthetics Society, Vol.13, No.4, pp.33-43.

10.12814/jkgss.2014.13.4.033
19

Ji, S., Gu, Q. and Xia, B. (2006), “Porosity dependence of mechanical properties of solid materials”, Journal of Materials Science, Vol.41, No.6, pp.1757-1768.

10.1007/s10853-006-2871-9
20

KIGAM (Korea Institute of Geoscience and Mineral Resources) (2014), Site Selection for Pilot-Scale CO2 Geologic Storage in the Korean Peninsula, 2012-0008916, pp.1-443.

21

Kim, H. B., Vilarrasa, V. and Makhnenko, R. Y. (2025), “Laboratory-Scale Assessment of CO2 Sealing Potential of Heterogeneous Caprock”, Water Resources Research, Vol.61, No.7, p.e2025WR040339.

10.1029/2025WR040339
22

Kim, H. J., Song, I. S., Chang, C. D., Lee, H. K. and Kim, T. H. (2013), “Relations between Physical and Mechanical Properties of Core Samples from the Bukpyeong and Pohang Basins”, The Journal of Engineering Geology, Vol.23, No.4, pp.329-340.

10.9720/kseg.2013.4.329
23

Kim, J. M., Ahn, J. Y., Heo, J. Y., Lee, S. J., Kim, Y. S., Moon, B. S. and Kim, Y. S. (2023), “Evaluation of Mechanical Characteristics and Applicability of Clayey Sand by Fines Content”, Journal of the Korean Geosynthetics Society, Vol.22, No.3, pp.47-59.

24

Kim, J. T. (2016), Study for the geochemical weathering process of reservoir rocks in the Janggi basin at CO2 sequestration conditions, M.S. Thesis, Pukyong National University. p.22.

25

Kim, K. S., Awad, M. M. and Espinoza, D. N. (2024), “A novel high-stress method to measure total horizontal stress in mudrocks subjected to uniaxial strain loading and unloading”, In 58th U.S. Rock Mechanics/Geomechanics Symposium, p.D031S029R006.

10.56952/ARMA-2024-0932
26

Kim, M. C., Gihm, Y. S., Jeong, R. Y., Shinn, Y. J. and Son, M. (2020), “Site selection and characterization for onshore 10,000-ton-class CO2 pilot storage in Early Miocene Janggi Basin, SE Korea: Storage potential and structural stability of siliciclastic-volcaniclastic storage combination”, International Journal of Greenhouse Gas Control, Vol.103, p.103174.

10.1016/j.ijggc.2020.103174
27

Kim, M. C., Gihm, Y. S., Son, E. Y., Son, M., Hwang, I. G., Shinn, Y. J. and Choi, H. S. (2015), “Assessment of the potential for geological storage of CO2 based on structural and sedimentologic characteristics in the Miocene Janggi Basin, SE Korea. Journal of the Geological Society of Korea, Vol.51, No.3, pp.253-271.

10.14770/jgsk.2015.51.3.253
28

Kim, S. K., Chang, C. D., Shinn, Y. J. and Kwon, Y. K. (2018), “Characteristics of Pohang CO2 Geological Sequestration Test Site”, The Journal of Engineering Geology, Vol.28, No.2, pp.175-182.

29

Kim, S. Y., Kim, J. T., Lee, M. H. and Wang, S. K. (2016), “Evaluation of the CO2 Storage Capacity by the Measurement of the scCO2 Displacement Efficiency for the Sandstone and the Conglomerate in Janggi Basin”, Economic and Environmental Geology, Vol.49, No.6, pp.469-477.

10.9719/EEG.2016.49.6.469
30

Kwon, Y. K. (2018), “Demonstration-scale Offshore CO2 Storage Project in the Pohang Basin, Korea”, The Journal of Engineering Geology, Vol.28, No.2, pp.133-160.

10.9720/KSEG.2018.2.133
31

Lee, K. W., Park, J. H., Jeoung, J. H., Seo, S. G. and Kang, K. N. (2024), “Evaluation of the Applicability of Inorganic Binders Using Industrial Byproducts as Soil Nailing Grouting Materials”, Journal of the Korean Geosynthetics Society, Vol.23, No.4, pp.79-87.

32

Luan, X., Di, B., Wei, J., Zhao, J. and Li, X. (2016), “Creation of synthetic samples for physical modelling of natural shale”, Geophysical Prospecting, Vol.64, No.4, pp. 898-914.

10.1111/1365-2478.12382
33

Luo, Z. and Airey, D. (2024), “The Mechanical Behaviour of an Artificial Siltstone”, Rock Mechanics and Rock Engineering, Vol.57, No.12, pp.10427-10445.

10.1007/s00603-024-04148-2
34

Mehranpour, M. H., Kulatilake, P. H., Xingen, M. and He, M. (2018), “Development of New Three-Dimensional Rock Mass Strength Criteria”, Rock Mechanics and Rock Engineering, Vol.51, No.11, pp.3537-3561.

10.1007/s00603-018-1538-6
35

Nygård, R., Gutierrez, M., Høeg, K. and Bjørlykke, K. (2004), “Influence of burial history on microstructure and compaction behaviour of Kimmeridge clay”, Petroleum Geoscience, Vol.10, No.3, pp.259-270.

10.1144/1354-079303-591
36

Olabode, A. and Radonjic, M. (2013), “Experimental Investigations of Caprock Integrity in CO2 Sequestration”, Energy Procedia, Vol.37, pp.5014-5025.

10.1016/j.egypro.2013.06.415
37

Park, J. Y., Lee, M. H. and Wang, S. K. (2013), “Study on the Geochemical Weathering Process of Sandstones and Mudstones in Pohang Basin at CO2 Storage Condition”, Economic and Environmental Geology, Vol.46, No.3, pp.221-234.

10.9719/EEG.2013.46.3.221
38

Park, J. Y., Yang, M. J., Kim, S. Y., Lee, M. H. and Wang, S. K. (2019), “Estimates of scCO2 Storage and Sealing Capacity of the Janggi basin in Korea Based on Laboratory Scale Experiments”, Minerals, Vol.9, No.9, p.515.

10.3390/min9090515
39

Pothana, P., Gokapai, V., Ifrene, G. and Ling, K. (2023), “Effect of Binding Material on the Acoustic, Elastic and Strength Properties of Artificial Granular Rocks”, In 57th U.S. Rock Mechanics/Geomechanics Symposium, p.ARMA-2023- 056.

10.56952/ARMA-2023-0560
40

Shukla, R., Ranjith, P., Haque, A. and Choi, X. (2010), “A review of studies on CO2 sequestration and caprock integrity”, Fuel, Vol.89, No.10, pp.2651-2664.

10.1016/j.fuel.2010.05.012
41

Simion, A. I., Grigoraş, C. G., Roşu, A. M. and Gavrilă, L. (2015), “Mathematical modelling of density and viscosity of nacl aqueous solutions”, Journal of Agroalimentary Processes and Technologies, Vol.21, No.1, pp.41-52.

42

Wang, S. K., Kim, H. J. and Lee, M. H. (2008), Characterization and evaluation of geologic formations for geological sequestration of carbon dioxide, M102KP01001807K160101820, pp.1-55.

43

Zheng, J., Zheng, L., Liu, H. H. and Ju, Y. (2015), “Relationships between permeability, porosity and effective stress for low-permeability sedimentary rock”, International Journal of Rock Mechanics and Mining Sciences, Vol.78, pp.304-318.

10.1016/j.ijrmms.2015.04.025
Information
  • Publisher :Korean Geosythetics Society
  • Publisher(Ko) :한국지반신소재학회
  • Journal Title :Journal of the Korean Geosynthetics Society
  • Journal Title(Ko) :한국지반신소재학회 논문집
  • Volume : 24
  • No :3
  • Pages :27-38
  • Received Date : 2025-08-11
  • Revised Date : 2025-09-17
  • Accepted Date : 2025-09-18
  • DOI :https://doi.org/10.12814/jkgss.2025.24.3.027
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