As global energy systems shift toward sustainability and decarbonization, subsurface storage of fluids—including carbon dioxide (CO₂), natural gas (NG), and hydrogen (H₂)—has emerged as a critical component of climate mitigation and energy reliability strategies. This chapter provides a comprehensive analysis of the well integrity challenges associated with Carbon Capture and Storage (CCS), Underground Natural Gas Storage (NGS), and Underground Hydrogen Storage (UHS), highlighting the stringent requirements for long-term containment, cyclic loading resilience, and material compatibility unique to each application. For CCS, well integrity is paramount to ensuring millennia-scale containment of CO₂, necessitating specialized focus on corrosion resistance in steel components, degradation of cement under carbonic acid attack, elastomer compatibility with supercritical CO₂, and rigorous abandonment and monitoring protocols. Advanced materials and sealing systems must be validated under reservoir-specific geochemical and geomechanical conditions. Cement micro-annuli, legacy well reactivation, and induced seismicity are explored as critical risks requiring predictive modeling and long-term MMV (Monitoring, Measurement, and Verification). In NGS applications, wells are subject to frequent and rapid pressure and temperature cycling, which can induce mechanical fatigue in casing, cement, and wellhead equipment. Deliverability assurance and leak prevention are central to operational and economic success. The chapter discusses cyclic fatigue management, pressure testing, and corrosion control strategies, alongside field data highlighting the primary causes of well failures in storage environments. The chapter also explores the emerging frontier of UHS, where the unique physical and chemical properties of hydrogen—including its low molecular weight, high diffusivity, and tendency to induce embrittlement—pose unprecedented integrity threats to steel casings and cement sheaths. Mechanisms such as hydrogen embrittlement (HE), hydrogen-induced cracking (HIC), and hydrogen blistering (HB) are examined in depth, along with mitigation strategies through alloy selection, coatings, and seal optimization. Salt cavern-specific geomechanical challenges and the impact of cyclic operations on casing design and cement integrity are also detailed. Through detailed case studies, laboratory data, corrosion rate modeling, and analytical leakage equations, this chapter equips engineers, researchers, and policymakers with a deep understanding of the technical complexities governing well integrity in subsurface storage applications. The insights provided form the basis for designing robust wells, managing long-term risks, and advancing safe and efficient storage of critical energy and climate-related fluids.

Integrity for Subsurface Storage Wells (CCS, Gas Storage, H2 Storage)

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发表日期：

2026年

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Ahmed Alsubaih,
Kamy Sepehrnoori

摘要

As global energy systems shift toward sustainability and decarbonization, subsurface storage of fluids—including carbon dioxide (CO₂), natural gas (NG), and hydrogen (H₂)—has emerged as a critical component of climate mitigation and energy reliability strategies. This chapter provides a comprehensive analysis of the well integrity challenges associated with Carbon Capture and Storage (CCS), Underground Natural Gas Storage (NGS), and Underground Hydrogen Storage (UHS), highlighting the stringent requirements for long-term containment, cyclic loading resilience, and material compatibility unique to each application. For CCS, well integrity is paramount to ensuring millennia-scale containment of CO₂, necessitating specialized focus on corrosion resistance in steel components, degradation of cement under carbonic acid attack, elastomer compatibility with supercritical CO₂, and rigorous abandonment and monitoring protocols. Advanced materials and sealing systems must be validated under reservoir-specific geochemical and geomechanical conditions. Cement micro-annuli, legacy well reactivation, and induced seismicity are explored as critical risks requiring predictive modeling and long-term MMV (Monitoring, Measurement, and Verification). In NGS applications, wells are subject to frequent and rapid pressure and temperature cycling, which can induce mechanical fatigue in casing, cement, and wellhead equipment. Deliverability assurance and leak prevention are central to operational and economic success. The chapter discusses cyclic fatigue management, pressure testing, and corrosion control strategies, alongside field data highlighting the primary causes of well failures in storage environments. The chapter also explores the emerging frontier of UHS, where the unique physical and chemical properties of hydrogen—including its low molecular weight, high diffusivity, and tendency to induce embrittlement—pose unprecedented integrity threats to steel casings and cement sheaths. Mechanisms such as hydrogen embrittlement (HE), hydrogen-induced cracking (HIC), and hydrogen blistering (HB) are examined in depth, along with mitigation strategies through alloy selection, coatings, and seal optimization. Salt cavern-specific geomechanical challenges and the impact of cyclic operations on casing design and cement integrity are also detailed. Through detailed case studies, laboratory data, corrosion rate modeling, and analytical leakage equations, this chapter equips engineers, researchers, and policymakers with a deep understanding of the technical complexities governing well integrity in subsurface storage applications. The insights provided form the basis for designing robust wells, managing long-term risks, and advancing safe and efficient storage of critical energy and climate-related fluids.