地下储氢库井筒完整性研究现状与发展建议OA

As a core technological pathway for large-scale hydrogen storage,underground hydrogen storage exhibits promising application prospect.Under the coupling action of cyclic loading with hydrogen reactivity and high permeability,the wellbores in underground hydrogen storage face the risks of failure.To this end,this paper reviews the types of possible wellbore failure during the operation period of underground hydrogen storage,and systematically elaborates the coupling mechanisms between cyclic injection and production process and hydrogen induced wellbore component damage.Based on this,the targeted prevention and control suggestions and future research directions are proposed.The following results are obtained.First,the main types of wellbore failure in underground hydrogen storage include wellbore metallic component damage,non-metallic seal element failure under the synergetic effect of cyclic injection and production and hydrogen,and sealing integrity failure of cement sheaths.Second,existing protective materials(e.g.surface coatings,hydrogen-resistant alloys,and polymer-based composite materials)can mitigate hydrogen embrittlement,microbial corrosion,and elastomer failure to some extent,but their long-term effectiveness under complex working conditions has yet to be fully validated.Third,the annulus pressure warning threshold calculation method which is established by introducing the critical stress of casing hydrogen embrittlement on the basis of multi-physics coupled framework further defines the safety boundary of annulus pressure.Fourth,the prevention and control of wellbore failure in underground hydrogen storage shall be carried out continuously from the aspects of string hydrogen embrittlement prevention and control,hydrogen-resistant material research&development,intelligent monitoring of hydrogen-cement sheath interaction mechanism and integrity,and annulus pressure control.In conclusion,the wellbore failure in underground hydrogen storage is the coupling product of multiple factors,and its future research shall focus on the construction of an integrity technical system covering materials,structures and monitoring based on the actual working conditions,to provide theoretical support and engineering guidance for the safe operation of underground hydrogen storage.