摘要
Rn、CO_(2)、Hg、H_(2)等断层气体被广泛应用于断层活动性以及断层结构特征的研究。当前,研究介质中压力变化与断层气间的关系是断层气映震研究的主要技术方法之一。新疆呼图壁地下储气库自建成以来,每年以周期性循环“注入/采出”模式运行,该运行模式带来的储气库气压变化会影响周围地区的地震活动。同时,这一定期加压存储与减压释放气体的过程为研究应力变化引起的断层气变化提供了天然的实验场。通过对呼图壁储气库开展断层气定期流动测量以及定点连续观测,获取反复加载、卸载气体过程中储气库及周边区域断层气体Rn、CO_(2)、Hg、H_(2)浓度的变化特征,在储气库区域内观测到明显的Hg、H_(2)浓度高值现象,其最大值分别为190ng/m^(3)和725.40ppm,且其空间分布特征表现为在储气库加压存储过程中,储气库区域内注采井附近的气体浓度高于储气库区域外;此外,长期连续观测结果表明,断层气H_(2)与储气库的压力变化存在一定的关系,H_(2)对储气库内压力变化的响应更为灵敏。对呼图壁储气库应力变化引起的断层气变化特征进行分析,可以认识不同应力状态下断层气变化特征,为地震台站勘选与建设、震情跟踪以及异常落实等提供地球化学科技支撑。
Earthquakes activities can cause the release of underground gas. Soil gases along faults such as radon,carbon dioxide,mercury and hydrogen are widely used in the study of fault activity and the characteristics of fault structure. At present,a great attention has been paid to study the relationship between pressure changes in the medium and gas along fault in studying fault gas reflection. Since the completion of Xinjiang Hutubi Underground Gas Storage,it has been operating in a cyclical “injection/production” mode every year. The gas storage pressure changes caused by such operation mode will have an impact on the seismic activity in the surrounding areas. At the same time of concerning the production and life safety of surrounding residents,this process of regular pressurized storage and decompression of gas release provides a natural testing ground for studying fault gas changes caused by stress changes. In this paper we carried out periodic fault gas measurement and continuous monitoring of fault gas at fixed points in Hutubi gas storage to obtain the fault gas Rn,CO_(2),Hg,H_(2) of the gas storage and the surrounding area during the repeated loading and unloading of the gas storage. Relatively high concentrations of Hg and H_(2) are observed in the gas storage area,with the maximum values of 190ng/m^(3) and 725. 40ppm respectively. In terms of spatial distribution characteristics during the process of pressurized storage in the gas storage,the gas concentration near the injection and production wells in the gas storage area is higher than that outside the gas storage area. In addition,the long-term continuous observation results show that the H_(2) has a certain relationship with the pressure change of the gas storage,and has a certain effect on the gas storage,which suggests that the H_(2) response to changes in internal pressure is more sensitive. Our results show that analyzing the characteristics of gas changes caused by stress changes in Hutubi gas storage can provide geochemical scientific and technological support to help the survey and selection,construction,earthquake situation tracking and anomaly implementation of seismic stations.
作者
蒋雨函
高小其
张磊
许秋龙
汪成国
陈其峰
范雪芳
Jiang Yuhan;Gao Xiaoqi;Zhang Lei;Xu Qiulong;Wang Chengguo;Chen Qifeng;Fan Xuefang(Key Laboratory of Crustal Dynamics,National Institute of Natural Hazards,Ministry of Emergency Management of China,Beijing 100085,China;Earthquake Agency of Xinjiang Uygur Autonomous Region,Urumqi 830011,China;Shandong Earthquake Agency,Jinan 250014,China;Shanxi Earthquake Agency,Taiyuan 030021,China)
出处
《中国地震》
北大核心
2021年第4期749-766,共18页
Earthquake Research in China
基金
国家重点研发计划(2019YFC1509203)
中国地震局地壳应力研究所中央级公益性科研院所基本科研业务专项(ZDJ2017-27)
中国大陆综合地球物理场观测仪器研发专项(J2218827)共同资助。
关键词
呼图壁储气库
断层气
气体地球化学
氢气
汞
流动观测
连续观测
Hutubi gas storage
Fault gas
Gas geochemistry
Hydrogen
Mercury
Fault gas measurement
Continuous monitoring
