Advertisement

Applied Geophysics

, Volume 15, Issue 3–4, pp 481–490 | Cite as

Q-factor estimation in CMP gather and the continuous spectral ratio slope method

  • Zong-Wei Wu
  • Yi-Jia Wu
  • Si GuoEmail author
  • Ming-Hua Xu
Article
  • 8 Downloads

Abstract

The attenuation factor or quality factor (Q-factor or Q) has been used to measure the energy attenuation of seismic waves propagating in underground media. Many methods are used to estimate the Q-factor. We propose a method to calculate the Q-factor based on the prestack Q-factor inversion and the generalized S-transform. The proposed method specifies a standard primary wavelet and calculates the cumulative Q-factors; then, it finds the interlaminar Q-factors using the relation between Q and offset (QVO) and the Dix formula. The proposed method is alternative to methods that calculate interlaminar Q-factors after horizon picking. Because the frequency spectrum of each horizon can be extracted continuously on a 2D time–frequency spectrum, the method is called the continuous spectral ratio slope (CSRS) method. Compared with the other Q-inversion methods, the method offers nearly effortless computations and stability, and has mathematical and physical significance. We use numerical modeling to verify the feasibility of the method and apply it to real data from an oilfield in Ahdeb, Iraq. The results suggest that the resolution and spatial stability of the Q-profile are optimal and contain abundant interlaminar information that is extremely helpful in making lithology and fluid predictions.

Keywords

Quality factor prestack Q estimation generalized S transform spectral ratio slope method Q versus offset 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Notes

Acknowledgements

We wish to thank the Geological Exploration & Development Research Institute of the Chuanqing Drilling Engineering Company Limited, CNPC, and the Department of Science and technology of Sichuan for their generous support.

References

  1. Adams, M., Kossentini, F., and Ward, R. K., 2001, Generalized S transform: IEEE Transactions on Signal Processing, 50(11), 2831–2842.Google Scholar
  2. An, Y., 2015, Fracture prediction using prestack Q calculation and attenuation anisotropy: Applied Geophysics, 12(3), 432–440.Google Scholar
  3. Bath, B. M., 1974, Spectral analysis in geophysics: Elsevier, Netherlands.Google Scholar
  4. Chen, K. G., Wang, W. W., Guo, J. Q., Qiu, C. N., and Wang, H. F., 2008, Study on the acoustic absorption characteristics of homogeneous gas–bearing sandstone: Well Logging Techonlogy (in Chinese), 32(02), 152–154, 163.Google Scholar
  5. Dasgupta, R., and Clark, R. A., 1998, Estimation of Q from surface seismic reflection data: Geophysics, 63(6), 2120–2128.Google Scholar
  6. Futterman, W. I., 1962, Dispersive body waves: Journal of Geophysical Research, 67(13), 5279–5291.Google Scholar
  7. Gao, J. H., Yang, S. L., and Wang, D. X., 2008, Quality factor extraction using instantaneous frequency at envelope peak of direct waves of VSP data: Chinese Journal of Geophysics, 51(03), 853–861.Google Scholar
  8. Hauge, P. S., 1981, Measurements of attenuation from vertical seismic profiles: Geophysics, 46, 1548–1558.Google Scholar
  9. Jiang, H. T., 2011, Forward and inverse method of attenuation features of pre–stack CMP gather: Master Thesis, Chang’an University, Xi’an.Google Scholar
  10. Kaderali, A., Jones, M., and Howlett, J., 2007, White Rose seismic with well data constraints: A case history. The Leading Edge: 26(6), 742–750, 752–754.Google Scholar
  11. Kjartansson, E., 1979, Constant Q–wave propagation and attenuation: Journal of Geophysical Research, 84(B9), 4737–4748.Google Scholar
  12. Rainer, T., 1991, The determination of the seismic Quality factor Q from VSP data: A comparison of different computational methods: Geophysical Prospecting, 1991, 39(1), 1–27.Google Scholar
  13. Reine, C., Clark, R., and Mirko, V. D. B., 2012, Robust prestack Q–determination using surface seismic data, part1: method and synthetic examples: Geophysics, 77(1), R45–R56.Google Scholar
  14. Stockwell, R. G., Mansinha, L., and Lowe, R. P., 1996, Localization of the complex spectrum: the S transform: IEEE Transactions on Signal Processing, 44(4), 998–1001.Google Scholar
  15. Tu, N., and Lu, W. K., 2010, Improve Q estimates with spectrum correction based on seismic wavelet estimation. Applied Geophysics, 7(3), 217–228.Google Scholar
  16. TW Spencer, 1982, Seismic Q–stratigraphy or dissipation: Geophysics, 47(47), 16–24.Google Scholar
  17. Wang, D. Y., Huang, J. P., Kong, X., Li, Z. C., and Wang, J., 2017, Improving the resolution of seismic traces based on the secondary time–frequency spectrum: Applied Geophysics, 14(2), 236–246.Google Scholar
  18. Wang, X. J., Yin, X. Y., and Wu, G. C., 2011, Estimation of quality factors Q from pre–stack data: Oil Geophysical Prospecting (in Chinese), 46(03), 423–428+500+327.Google Scholar
  19. Wang, Y. H., 2003, Quantifying the effectiveness of stabilized inverse Q filtering: Geophysics, 68(1), 337–345.Google Scholar
  20. Wang, Y. H., 2006, Inverse Q–filter for seismic resolution enhancement: Geophysics, 71(3), V51–V60.Google Scholar
  21. Wang, Z. J., Cao, S. Y., Zhang, H. R., et al., 2015, Estimation of quality factors by energy ratio method: Applied Geophysics, 12(1), 86–92.Google Scholar
  22. Ward, R. W., 1980, Mapping seismic attenuation within geothermal systems using teleseisms with application to the Geysers2 Clear Lake region: Geophys. Res., 85(B10), 5227–5236.Google Scholar
  23. Wei, W., Wang, X. J., and Li, H. M., 2011, A study on Q estimation from CMP gather in wavelet domain: Geophysical Prospecting for Petroleum, 50(4), 355–360.Google Scholar
  24. Wen, R. X., 2009, Frequency attenuation for gas potential prediction of the volcanic reservoirs in Qingshen gas field: Natural Gas Industry (in Chinese), 29(8), 26–28.Google Scholar
  25. Zhang, C. J., and Ulrych, T. J., 2002, Estimation of quality factors from CMP records: Geophysics, 67(5), 1542–1547.Google Scholar
  26. Zhao, J., Gao, J. H., Wang, D. X., and Wang, L. L., 2013, Estimation of quality factor Q from pre–stack CMP records: Chinese Journal of Geophysics, 56(7), 2413–2428.Google Scholar
  27. Zhao, W., and Ge, Y., 2008, Estimation of Q from VSP data with zero offset in wavelet domain: Chinese Journal of Geophysics (in Chinese), 51(04), 1202–1208.Google Scholar

Copyright information

© Editorial Office of Applied Geophysics and Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Geological Exploration & Development Research Institute, CCDE, CNPCChengduChina
  2. 2.University of Electronic Science and Technology of China, School of Resources and EnvironmentChengduChina

Personalised recommendations