| Autor: |
Li, Tianyang, Gu, Yu Jeffrey, Lawton, Donald C., Gilbert, Hersh, Macquet, Marie, Savard, Genevieve, Wang, Jingchuan, Innanen, Kristopher A., Yu, Nian |
| Předmět: |
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| Zdroj: |
Journal of Geophysical Research. Solid Earth; Dec2022, Vol. 127 Issue 12, p1-17, 17p |
| Abstrakt: |
Monitoring subsurface velocity variations due to industrial activities using passive seismic imaging techniques has gained popularity in recent years. In this study, we examine the spatiotemporal variations of persistent, non‐ambient seismic noise during CO2 sequestration at the Containment and Monitoring Institute Field Research Station near Brooks, Alberta, Canada. Based on the temporal migration and power spectral density (PSD) analysis of continuous seismic records from both a dense geophone array and "X"‐shaped geophone lines operated from June to August 2019, we detect two non‐ambient local noise sources correlated with the local industrial activities during the two months: a dominant noise source (1–5 Hz) southeast of the study region and a slightly weaker noise source in the higher frequency range (5–15 Hz) around the injection well. The former noise source overlaps with the operations near a submersible disposal pump. The substantial diurnal variations in noise levels in PSD as a function of time of day, month and location are further evidence of these two noise sources. We propose that the persistent noise source around the injection well originated from the subsurface microtremors caused by the coupled interaction between the injected CO2 fluid and formation rocks. The proposed methods based on passive microseismic noise offer a potentially valuable strategy for long‐term evaluation of the safety of CO2 sequestration, which can be extended to future integrity monitoring of underground energy storage. Plain Language Summary: Carbon capture and storage have been broadly considered a critical climate change mitigation tool to reduce greenhouse gas emissions. To better understand possible seismic hazards due to CO2 injection, we analyze data from a dense array of seismic sensors operated from June to August 2019 to examine the existence and location of noise sources around the CO2 injection well at the Containment and Monitoring Institute Field Research Station in southern Alberta. We detect two local noise sources during CO2 injection experiments. The spatial and temporal distribution of the low‐frequency (1–5 Hz) noise source correlated with subsurface water disposal in the southeastern corner of the study area. The noise source located near the injection well is associated with injection activities and falls in the 5–15 Hz frequency range. Diurnal variations and changes in power spectral density at different station locations further confirm the presence of these two persistent noise sources. We propose that the noise source around the injection well is most likely caused by CO2 fluid‐rock interaction. The proposed methods are particularly cost‐effective for the long‐term monitoring of underground energy storage. Key Points: The spatiotemporal variations of non‐ambient seismic noise are examined using continuous records from a dense geophone arrayA dominant noise source in the southeast and a weaker noise source around the injection well are detected during CO2 sequestrationThe coupled interaction between the injected CO2 fluids and formation rocks is supposed to be in charge of the noise source around the well [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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