Tremor signals during fluid injection are generated by fault slip

• 成果类型: Article
• 署名作者: Niyogi, Shankho; Ghosh, Abhijit; Kumar, Abhash; Hammack, Richard W. W.
• 署名单位: University of California System; University of California Riverside; United States Department of Energy (DOE); National Energy Technology Laboratory - USA
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-9670
• DOI: 10.1126/science.adh1331
• 发表日期: 2023-08-04
• 页码: 553-558
• 关键词: duration seismic events; tight-gas reservoirs; long-period; induced earthquakes; tectonic tremor; hydraulic stimulation; subduction zone; harmonic tremor; ice-stream; oklahoma

摘要

Seismic tremor signals, also known as long-period, long-duration signals, have been reported in several locations where fluid injection for enhanced oil and gas exploration is taking place. However, the origin of these signals remains poorly constrained. We studied seismic tremor signals in Wellington Field, Kansas, using a seismic array during a carbon dioxide injection program. We show that these signals are generated below the surface during the time of carbon dioxide injection. They have a distinct spectral signature, similar to those observed in glacial and volcanic environments. The tremor sources are located near the injection site and aligned with preexisting faults. Modeling results imply that such tremors are generated by frictional slip on fault. These observations may reveal an important deformation mode, which is useful for studying associated stress, seismicity, and triggering, as well as for tracking fault activities during injection operations of all fluids, including supercritical carbon dioxide.