Temporal variation of the shallow subsurface at the Aquistore CO2storage site associated with environmental influences using a continuous and controlled seismic source

التفاصيل البيبلوغرافية
العنوان: Temporal variation of the shallow subsurface at the Aquistore CO2storage site associated with environmental influences using a continuous and controlled seismic source
المؤلفون: Ikeda, Tatsunori, Tsuji, Takeshi, Takanashi, Mamoru, Kurosawa, Isao, Nakatsukasa, Masashi, Kato, Ayato, Worth, Kyle, White, Don, Roberts, Brian
المصدر: Journal of Geophysical Research - Solid Earth; April 2017, Vol. 122 Issue: 4 p2859-2872, 14p
مستخلص: The development of reliable systems for monitoring injected CO2is essential in carbon capture and storage projects. We applied time‐lapse surface wave analysis to measure temporal variations of the shallow subsurface among 11 periods (0.2–21.6 days) of continuous seismic data acquired from 2014 to 2016 at the Aquistore CO2storage site in Canada. We focused on monitoring environmental influences on shallow seismic velocity, which are unrelated to CO2injection into deep reservoirs. A continuous, controlled seismic source system called Accurately Controlled Routinely Operated Signal System was used to enhance the temporal resolution and source repeatability. Observed phase velocities were clearly higher in winter than in warmer seasons. The seasonal variation could be reproduced by an increase in the shallow Swave velocity during winter associated with the greater extent of freezing of partially saturated rock. We also observed gradual increases or decreases in phase velocities as the seasons changed, which could be related to gradual freezing or melting of ice. Our monitoring system thus could be effective for monitoring temporal variations of the shallow subsurface associated with the degree of freezing. Furthermore, the high temporal stability of our monitoring approach in warm seasons may make it possible to immediately identify CO2leakage in the shallow subsurface. We monitored the shallow subsurface at the Aquistore CO2storage site using the ACROSS source systemWe estimated near‐surface Swave velocity variations possibly related to changes in the degree of freezing of partially saturated rockHigh temporal stability of our monitoring approach may make it possible to immediately identify CO2leakage in the shallow subsurface
قاعدة البيانات: Supplemental Index
الوصف
تدمد:21699313
21699356
DOI:10.1002/2016JB013691