不同类型复杂地下储气库建库难点与攻关方向

Construction difficulties and research directions of various complex UGSs

地下储气库(以下简称储气库)在保障天然气安全供应方面发挥了不可替代的重要作用。为推进中国储气库业务高质量发展,有效应对天然气安全保供压力,总结了国外储气库建设与运行关键技术现状,梳理了国内储气库建设历程和形成的特色理论技术,分析了我国储气库领域面临的突出挑战,提出了未来储气库发展与攻关方向。研究结果表明:①国外储气库建库与运行技术成熟、装备配套、标准完善,建成了气藏型、油藏型、盐穴型、水层型等多类型储气库;②中国在库容设计、井筒质量控制、大排量注采设计、地面处理工艺与装备、风险识别监测以及盐穴造腔等方面形成了特色技术;③中国储气库在“扩容、达产”及提高库容利用效率、高含水油藏与低渗透气藏和复杂连通老腔等新类型储气库建库技术等系列领域面临挑战;④亟需破解5大科学问题,即超压背景下储气地质体密封性弱化动力学机制、高含水油藏建库储气空间扩展与注排控制理论、盐穴储气库强制对流溶蚀—扩散流固耦合机理、大尺寸井井壁失稳力学—化学耦合机理、长周期注采储气库完整性失效机理与灾害演化机理;⑤亟需解决6大技术问题,即提高库容动用率、新类型储气库建库、提高单井产能和老井处置、地面处理关键装备、风险管控以及数字化智能化等技术。结论认为,中国在常规气藏选址评价、建库技术方面已达到国际领先水平;“十四五”期间中国储气库库址资源向劣质化、复杂化、多样化转变,亟需建立不同类型储气库建库与运行体系,实现关键设备国产化,推动中国储气库数字化转型,打造储气库原创技术策源地。

Underground gas storage(hereinafter referred to as UGS)plays an irreplaceable role in ensuring safe natural gas supply.In order to promote the high-quality development of domestic UGS business and effectively cope with the pressure of safe natural gas supply,this paper summarizes the current operation situations and key technologies of foreign UGSs,and analyzes the construction history and special theories and technologies of domestic UGSs.In addition,the obvious challenges in the field of UGS in China are analyzed,and the future UGS development and research directions are pointed out.And the following research results are obtained.First,foreign countries have mature technologies,complete equipment and perfect standards for UGS construction and operation,and have built up a varieties of UGGs in gas reservoirs,oil reservoirs,salt caverns and aquifers.Second,China has developed special technologies for storage capacity design,wellbore quality control,high-rate injection and production design,surface processing,risk identification and monitoring,and solution mining.Third,the challenges to UGSs in China lie in the storage capacity expansion and production,the storage capacity utilization efficiency improvement,and the construction technology,and so on.Fourth,the following five major scientific problems need solving urgently:dynamic mechanism of sealing weakening of gas-bearing geologic body under overpressure,gas storage space expansion and injection–drainage control theory of UGS rebuilt from oil reservoir with high water cut,fluid–solid coupling mechanism of forced convection solution and diffusion,mechanics–chemistry coupling mechanism of wellbore instability in large-size well,and integrity failure mechanism and disaster evolution mechanism of UGSs during long-term injection and production.Fifth,the following six major technical problems need to solve promptly,including improving storage capacity utilization rate,building new types of UGSs,increasing single well production capacity,and other issues like old well disposal,key equipment for surface treatment,risk control,and digital intelligence.In conclusion,China has reached the international leading level in the site selection&evaluation and construction of conventional gas-reservoir UGSs.What's more,during the"14th Five-Year Plan",the UGS site resources in China become inferior,complicated and diverse.Therefore,it is in an urgent need to establish construction and operation systems for different types of UGSs,localize key equipment,promote the digital transformation of UGSs,and set up a cradle of original UGS technologies.