Q estimation based on logarithmic spectral areas with different high and low frequencies
An Yong♦1,2 and Wang Xin-You♦1,2,3
1. State Key Laboratory of Petroleum Resource and Prospecting, China University of Petroleum, 102249, Beijing, China.
2. CNPC Key Laboratory of Geophysical Exploration, China University of Petroleum, 102249, Beijing, China.
3. China Construction Northeast Design and Research Institute Co., Ltd. 110000, Shenyang, China.
Abstract When a seismic wave propagates through subsurface viscoelastic media, the formation absorbs the high-frequency energy of the seismic wave more strongly than the lowfrequency energy. As the depth and the off set increase, the difference between the logarithmic spectral areas with high and low frequencies gradually increases. Based on this seismic wave characteristic, we have developed a novel Q-estimation method based on logarithmic spectral area difference of high and low frequencies (referred to as the LSAD_LH method). In this paper, we derive the theoretical relationship between the Q value and difference of logarithmic spectral areas with high and low frequencies and prove the applicability of the LSAD_LH method using a single-layer medium numerical model. To verify the sensitivity of the LSAD_LH method to bandwidth selection and noise, we compare the LSAD_LH method with two credible methods—the logarithmic spectral ratio (LSR) and logarithmic spectral area difference (LSAD) methods using a synthetic model containing the random noise. The results demonstrate that the LSAD_LH method is not highly dependent on bandwidth, and in terms of noise immunity, it is significantly better than the LSR method and has the same advantages as the LSAD method. To further highlight the advantages of the LSAD_LH method, we apply the LSAD_LH and LSAD methods to the vertical seismic profiling (VSP) numerical simulation of the multilayer media and the fi eld zero-off set VSP data. The application of the two cases proves the applicability of the LSAD_LH method and the accuracy of the high Q-value estimation relative to the LSAD method. Moreover, via the transmission coefficient, the LSAD_LH method overcomes the weakness of the LSAD method.
This research is supported in partly by National Nature Science Foundation of China (Grant No. U1562110 )
Corresponding Authors: An Yong (Email: yongan@cup.edu.cn) ； Wang Xin-You (Email: wang_xinyou@163.com)
E-mail: yongan@cup.edu.cn；wang_xinyou@163.com
About author: An Yong is an Associate professor and a master student supervisor at the China University of Petroleum (Beijing). He obtained a bachelor’s degree in Applied Geophysics from the China University of Petroleum (East China) in 1996, a master’s degree in Earth Exploration and Information Technology from the China University of Petroleum (Beijing) in 1999, and a Ph.D. in Solid Geophysics from the Institute of Geology and Geophysics, Chinese Academy of Sciences in June 2005. He is mainly engaged in the teaching of digital signal processing, principles of seismic exploration, and scientific research in seismic data processing and inversion.
Wang Xin-You is an Assistant Engineer at China Construction Northeast Design and Research Institute Co., Ltd. He obtained his bachelor’s degree in Investigation Technology and Engineering from the Anhui University of Science and Technology in 2017 and his master’s degree in Geophysics from the China University of Petroleum (Beijing) in 2020. He is mainly engaged in engineering survey and design work and engineering survey and construction equipment research work.
Cite this article:
. Q estimation based on logarithmic spectral areas with different high and low frequencies[J]. APPLIED GEOPHYSICS, 2021, 18(1): 75-84.
Wang Zong-Jun, Cao Si-Yuan, Zhang Hao-Ran, Qu Ying-Ming, Yuan Dian, Yang Jin-Hao, Zhang De-Long, Shao Guan-Ming. Estimation of quality factors by energy ratio method[J]. APPLIED GEOPHYSICS, 2015, 12(1): 86-92.
2021, Vol. 18 
