地学前缘 ›› 2024, Vol. 31 ›› Issue (6): 252-260.DOI: 10.13745/j.esf.sf.2024.7.23

• 地热开发利用技术 • 上一篇    下一篇

干热岩开发断层滑动及诱发地震风险研究:以唐山马头营干热岩场地为例

上官拴通1(), 田兰兰1, 潘苗苗1, 杨风良1, 岳高凡2,3,*(), 苏野1, 齐晓飞1   

  1. 1.河北省煤田地质局 第二地质队(河北省干热岩研究中心), 河北 邢台 054001
    2.中国地质科学院 水文地质环境地质研究所, 河北 石家庄 050061
    3.自然资源部地热与干热岩勘查开发技术创新中心, 河北 石家庄 050061
  • 收稿日期:2024-02-21 修回日期:2024-05-10 出版日期:2024-11-25 发布日期:2024-11-25
  • 通信作者: *岳高凡(1989—),男,副研究员,主要从事地热地质与多场耦合方面的研究工作。E-mail: gaofan3904@163.com
  • 作者简介:上官拴通(1983—),男,正高级工程师,主要从事地热地质及水文地质相关工作。E-mail: 359024048@qq.com
  • 基金资助:
    河北省唐山市马头营凸起区干热岩开发关键技术集成研究与示范项目(20374102D);中国地质科学院基本科研业务费专项(YK202309)

Fault slip tendency and induced-earthquake risks in hot dry rock development: A case study in the Tangshan Matouying HDR site

SHANGGUAN Shuantong1(), TIAN Lanlan1, PAN Miaomiao1, YANG Fengliang1, YUE Gaofan2,3,*(), SU Ye1, QI Xiaofei1   

  1. 1. The Second Geological Team of Hebei Coal Geology Bureau (Hebei Hot Dry Rock Research Center), Xingtai 054001, China
    2. Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China
    3. Technological Innovation Center of Geothermal & Hot Dry Rock Exploration and Development, Ministry of Natural Resources, Shijiazhuang 050061, China
  • Received:2024-02-21 Revised:2024-05-10 Online:2024-11-25 Published:2024-11-25

摘要:

诱发地震是干热岩大规模开发面临的主要问题之一,断层滑动和流体超压是较大地震的两大主要诱因,同时每个场地的诱发地震情况受具体的地质条件控制。本文选取马头营干热岩场地为研究区,在地震地质、构造地质、地热地质条件分析基础上,建立水热力多场耦合数值模型,综合考虑地应力场和多条断裂的影响,通过计算断层滑动趋势评估干热岩开发过程中的断层稳定性,并依据注入扰动体积估算长期注入可能诱发的最大震级。结果显示,10年干热岩开发过程中,马头营干热岩场地断层的孔隙压力变化不超过0.8 MPa,不会引起断层上有效应力的明显变化;注采期间断层滑动趋势均远低于滑动预警线,注采过程安全。优选出两种适用于马头营场地的地震矩计算模型,10年开采过程中可能诱发的最大震级为2.0级至2.1级。研究成果不仅能够为马头营场地干热岩安全规模化开发提供支撑,而且有助于深入理解工程活动影响下的地球动力学过程。

关键词: 干热岩, 诱发地震, 断层滑动趋势, 最大震级, 多场耦合

Abstract:

Induced earthquakes are one of the major problems in hot dry rock (HDR) development. Fault slip and fluid overpressure are the two main causes of large induced earthquakes, whilst local geological conditions affect the characteristics of the earthquakes. This study selects the Matouying HDR site was selected as the study area. The seismology, tectonics, and geothermal characteristics of the HDR site were analyzed in great detail. A THM multifield coupling numerical model was established, taking into account the impact of geostresses and multiple faults. The fault stability during the HDR development was evaluated based on the calculated slip tendency of the faults, and the maximum magnitude of injection-induced slip was estimated based on the calculated volume of disturbed rocks. According to the results, during the 10-year HDR development, pore pressure on the faults changed by no more than 0.8 MPa, causing no significant changes in the effective stress on faults. The slip tendency of the faults during exploration was far lower than the slip warning threshold, and the injection process was safe. Two models for calculating seismic moment were optimized, and the calculated maximum magnitude of induced earthquakes by a 10-year loop was between 2.0—2.1. Results from this study can not only support safe development of HDR at the Matouying HDR site, but also help to gain deeper understanding of the geodynamic processes affected by engineering activities.

Key words: hot dry rock, induced earthquakes, fault slip trend, maximum magnitude, multi-field coupling

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