Geophysical techniques play key roles in the measuring, monitoring, and verifying the safety of CO2 sequestration and in identifying the efficiency of CO2-enhanced oil recovery. Although geophysical monitoring techniq...Geophysical techniques play key roles in the measuring, monitoring, and verifying the safety of CO2 sequestration and in identifying the efficiency of CO2-enhanced oil recovery. Although geophysical monitoring techniques for CO2 sequestration have grown out of conventional oil and gas geophysical exploration techniques, it takes a long time to conduct geophysical monitoring, and there are many barriers and challenges. In this paper, with the initial objective of performing CO2 sequestration, we studied the geophysical tasks associated with evaluating geological storage sites and monitoring CO2 sequestration. Based on our review of the scope of geophysical monitoring techniques and our experience in domestic and international carbon capture and sequestration projects, we analyzed the inherent difficulties and our experiences in geophysical monitoring techniques, especially, with respect to 4D seismic acquisition, processing, and interpretation.展开更多
The Westwood Mine aims to reuse the tailings storage facility #1(TSF #1) for solid waste storage, but,downstream of the Northwest dike is considered critical in terms of stability. This paper uses numerical modeling a...The Westwood Mine aims to reuse the tailings storage facility #1(TSF #1) for solid waste storage, but,downstream of the Northwest dike is considered critical in terms of stability. This paper uses numerical modeling along with geophysical monitoring for assessing the Northwest dike stability during the restoration phase. The impact of waste rock deposition in the upstream TSF #1 is considered. The geophysical monitoring is based on electrical resistivity methods and was used to investigate the internal structure of the dike embankment in different deposition stages. The numerical simulations were performed with SLOPE/W code. The results show a factor of safety well above the minimum recommended value of 1.5. Geophysical monitoring revealed a vertical variation in the electrical resistivity across the dike, which indicates a multilayer structure of the embankment. Without any current in situ data, the geophysical monitoring helped estimating the nature of the materials used and the internal structure of the embankment. These interpretations were validated by geological observation of geotechnical log of the embankment. Based on this study, it is recommended that the water polishing pond be partly filled before waste rock is deposited in TSF #1. In addition, to ensure the stability of the dike, the piezometric head monitoring prior to and during waste rock deposition is recommended.展开更多
The transportable optical clock can be deployed in various transportation vehicles,including aviation,aerospace,maritime,and land-based vehicles;provides remote time standards for geophysical monitoring and distribute...The transportable optical clock can be deployed in various transportation vehicles,including aviation,aerospace,maritime,and land-based vehicles;provides remote time standards for geophysical monitoring and distributed coherent sensing;and promotes the unmanned and lightweight development of global time network synchronization.However,the current transportable version of laboratory optical clocks is still limited by factors such as environmental sensitivity,manual maintenance requirements,and high cost.Here we report a single-person portable optical frequency standard using the recently proposed atomic-filter-based laser“Voigt laser”as the local oscillator.It is worth mentioning that due to the inherent characteristics of Voigt lasers,the Voigt optical frequency standard can maintain turn-key functionality under harsh environmental impacts without any manual maintenance requirement.In our experiment,conducted over a duration of 12 min,we subjected the laser diode to multiple temperature shocks,resulting in a cumulative temperature fluctuation of 15℃.Following each temperature shock event,the Voigt optical frequency standard automatically relocked and restored the frequency output.Therefore,this demonstration marks a significant technological breakthrough in automatic quantum devices and might herald the arrival of fully automated time network systems.展开更多
基金supported by National 863 Program Grant 2012AA050103 and Grant 2011KTCQ03-09
文摘Geophysical techniques play key roles in the measuring, monitoring, and verifying the safety of CO2 sequestration and in identifying the efficiency of CO2-enhanced oil recovery. Although geophysical monitoring techniques for CO2 sequestration have grown out of conventional oil and gas geophysical exploration techniques, it takes a long time to conduct geophysical monitoring, and there are many barriers and challenges. In this paper, with the initial objective of performing CO2 sequestration, we studied the geophysical tasks associated with evaluating geological storage sites and monitoring CO2 sequestration. Based on our review of the scope of geophysical monitoring techniques and our experience in domestic and international carbon capture and sequestration projects, we analyzed the inherent difficulties and our experiences in geophysical monitoring techniques, especially, with respect to 4D seismic acquisition, processing, and interpretation.
基金financially supported by NSERC (Natural Sciences and Engineering Research Council of Canada) Engage grants
文摘The Westwood Mine aims to reuse the tailings storage facility #1(TSF #1) for solid waste storage, but,downstream of the Northwest dike is considered critical in terms of stability. This paper uses numerical modeling along with geophysical monitoring for assessing the Northwest dike stability during the restoration phase. The impact of waste rock deposition in the upstream TSF #1 is considered. The geophysical monitoring is based on electrical resistivity methods and was used to investigate the internal structure of the dike embankment in different deposition stages. The numerical simulations were performed with SLOPE/W code. The results show a factor of safety well above the minimum recommended value of 1.5. Geophysical monitoring revealed a vertical variation in the electrical resistivity across the dike, which indicates a multilayer structure of the embankment. Without any current in situ data, the geophysical monitoring helped estimating the nature of the materials used and the internal structure of the embankment. These interpretations were validated by geological observation of geotechnical log of the embankment. Based on this study, it is recommended that the water polishing pond be partly filled before waste rock is deposited in TSF #1. In addition, to ensure the stability of the dike, the piezometric head monitoring prior to and during waste rock deposition is recommended.
基金Innovation Program for Quantum Science and Technology(2021ZD0303200)National Natural Science Foundation of China(62405007,624B2010)+1 种基金China Postdoctoral Science Foundation(BX2021020)Wenzhou Major Science and Technology Innovation Key Project(ZG2020046)。
文摘The transportable optical clock can be deployed in various transportation vehicles,including aviation,aerospace,maritime,and land-based vehicles;provides remote time standards for geophysical monitoring and distributed coherent sensing;and promotes the unmanned and lightweight development of global time network synchronization.However,the current transportable version of laboratory optical clocks is still limited by factors such as environmental sensitivity,manual maintenance requirements,and high cost.Here we report a single-person portable optical frequency standard using the recently proposed atomic-filter-based laser“Voigt laser”as the local oscillator.It is worth mentioning that due to the inherent characteristics of Voigt lasers,the Voigt optical frequency standard can maintain turn-key functionality under harsh environmental impacts without any manual maintenance requirement.In our experiment,conducted over a duration of 12 min,we subjected the laser diode to multiple temperature shocks,resulting in a cumulative temperature fluctuation of 15℃.Following each temperature shock event,the Voigt optical frequency standard automatically relocked and restored the frequency output.Therefore,this demonstration marks a significant technological breakthrough in automatic quantum devices and might herald the arrival of fully automated time network systems.
