Induced earthquake source process imaging and groundwater chemistry monitoring in the Western Canada sedimentary basin

加拿大西部沉积盆地诱发地震震源过程成像和地下水化学监测

• 批准号: 494141-2016
• 负责人: Liu, Yajing
• 金额: $ 11.19万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Strategic Projects - Group
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=693863
• 关键词: Induced; earthquake; source; process; imaging

In the past 5 years, there has been a drastic increase in the number of earthquakes potentially induced by fluid injection during unconventional oil and gas extraction in North America, including previously seismically quiescent areas. In particular, the occurrences of magnitude 4 and greater earthquakes associated with hydraulic fracturing operations in northeast British Columbia and Alberta has led to temporarily shut-down of well production and caused safety concerns among local communities. Despite the densification of seismic monitoring network, the detailed source process and triggering threshold of injection induced earthquakes remains a critical challenge to seismic hazard assessment and mitigation. In this project, we proposed to incorporate innovative geophysical, hydrogeological and geochemical monitoring techniques and numerical tools, to quantitatively image and model induced seismicity source processes at two hydraulic fracturing wells and one disposal well in northeast BC and west Alberta. At each target site, we will install a dense array composed of broadband seismometers and integrated seismo-geodetic systems for recording seismographs of induced earthquakes, and angled reflectors for enhanced Interferometry Satellite Aperture Radar ground motion imaging. We will also conduct groundwater chemistry and isotope surveys at the target sites, in order to identify temporal variations related to fluid injection with a focus on potential earthquake precursory signals. Field observations will be used to constrain the poroelastic model for simulating fluid pressure and solid matrix stress changes due to injection, and for designing injection strategies that reduce the likelihood of triggered seismic slip on pre-existing faults. The outcome of this project will provide unbiased scientific knowledge for the public policy making by our supporting organization GSC as well as regulatory policy adjustment by provincial oil and gas commissions.

过去5年中，北美非常规石油和天然气开采过程中流体注入可能引发的地震数量急剧增加，其中包括以前地震静止的地区。特别是，不列颠哥伦比亚省东北部和艾伯塔省发生与水力压裂作业相关的4级及以上地震，导致油井生产暂时停止，并引起当地社区的安全担忧。尽管地震监测网络不断致密，但注入诱发地震的详细震源过程和触发阈值仍然是地震灾害评估和缓解的关键挑战。在该项目中，我们建议结合创新的地球物理、水文地质和地球化学监测技术和数值工具，对不列颠哥伦比亚省东北部和艾伯塔省西部的两口水力压裂井和一口处置井的诱发地震源过程进行定量成像和建模。在每个目标地点，我们将安装由宽带地震仪和集成地震大地测量系统组成的密集阵列，用于记录诱发地震的地震仪，以及用于增强干涉测量卫星孔径雷达地面运动成像的倾斜反射器。我们还将在目标地点进行地下水化学和同位素调查，以确定与流体注入相关的时间变化，重点关注潜在的地震前兆信号。现场观测将用于约束多孔弹性模型，以模拟由于注入引起的流体压力和固体基质应力变化，并用于设计注入策略，以减少在预先存在的断层上触发地震滑动的可能性。该项目的成果将为我们的支持机构GSC的公共政策制定以及各省油气委员会的监管政策调整提供公正的科学知识。