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Influencing factors of seismic signals generated by un-tuned large volume airgun array in a land reservoir |
Meng Chen1, Wei Yang1, Weitao Wang1, Baoshan Wang1, Hongkui Ge2, Li Chen3, Yansheng Ding3, Jiyan Qiao3, Yong Chen1 |
1 Key Laboratory of Seismic Observation and Geophysical Imaging, Institute of Geophysics, China Earthquake Administration, Beijing 100081, China
2 Unconventional Natural Gas Institute in China University of Petroleum, Beijing 102249, China
3 Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China |
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Abstract Un-tuned large volume airgun array in a water reservoir is recently proposed as a new way to generate seismic waves on land. It can be used to explore the earth velocity structure and its temporal variations as well. However, the characteristics of seismic signals (especially far-field signals) from an airgun array in a reservoir and its affecting factors (firing pressure, airgun towing depth, water level of the reservoir, etc.) has not been adequately studied. We analyzed the seismic data collected from field experiments at Binchuan Transmitting Seismic Station in 2011 and 2013 and found that (1) The similarity of seismic signals decrease with distance, which is most likely induced by the decay of signal amplitude and signal to noise ratio (SNR); (2) The amplitudes of far-field airgun signals are almost linearly proportional to the firing pressure; (3) The towing depth of airgun has less effects on the far-field signals; (4) The amplitudes of far-field airgun signals are proportional to the water level of the reservoir.
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Received: 15 December 2013
Published: 25 April 2014
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Fund:China National Special Fund for Earthquake Scientific Research in Public Interest (No. 201208004), National Natural Science Foundation of China (Nos. 41222029 and 41174040), Basic Research and Development Operations Special Fund of the Institute of Geophysics, China Earthquake Administration (No. DQJB10A01), and Foundation for Young Scientists of Yunnan Earthquake Administration (No. 201407) |
Corresponding Authors:
Meng Chen
E-mail: eamonustc@gmail.com
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