Study of S-wave ray elastic impedance for identifying lithology and fluid
Gong Xue-Ping1,2, Zhang Feng1,2, Li Xiang-Yang1,2, and Chen Shuang-Quan1,2
1. State Key Laboratory of Petroleum Resource and Prospecting, China University of Petroleum, Beijing, 102249, China.
2. CNPC Key Laboratory of Geophysical Prospecting, China University of Petroleum, Beijing, 102249, China.
Abstract：
In this paper, we derive an approximation of the SS-wave reflection coefficient and the expression of S-wave ray elastic impedance (SREI) in terms of the ray parameter. The SREI can be expressed by the S-wave incidence angle or P-wave reflection angle, referred to as SREIS and SREIP, respectively. Our study using elastic models derived from real log measurements shows that SREIP has better capability for lithology and fluid discrimination than SREIS and conventional S-wave elastic impedance (SEI). We evaluate the SREIP feasibility using 25 groups of samples from Castagna and Smith (1994). Each sample group is constructed by using shale, brine-sand, and gas-sand. Theoretical evaluation also indicates that SREIP at large incident angles is more sensitive to fluid than conventional fluid indicators. Real seismic data application also shows that SREIP at large angles calculated using P-wave and S-wave impedance can efficiently characterize tight gas-sand.
GONG Xue-Ping,ZHANG Feng,LI Xiang-Yang et al. Study of S-wave ray elastic impedance for identifying lithology and fluid[J]. APPLIED GEOPHYSICS, 2013, 10(2): 145-156.
[1]
Aki, K., and Richards, P. G., 1980, Quantitative seismology: theory and methods: W. H. Freeman and Company, New York.
[2]
Avseth, P., Mukerji, T., and Mavko, G., 2005, Quantitative seismic interpretation: applying rock physics tools to reduce interpretation risk: Cambridge University Press, England.
[3]
Castagna, J. P., and Smith, S. W., 1994, Comparison of AVO indicators: A modeling study: Geophysics, 59(12), 1849 - 1855.
[4]
Connolly, P., 1999, Elastic impedance: The Leading Edge, 18(4), 438 - 452.
[5]
Duffaut, K., Alsos, T., Landre, M., Rogn?, H., and Al-Najjar, N. F., 2000, Shear-wave elastic impedance: The leading Edge, 19, 1223 - 1229.
[6]
Foster, D. J., Keys, R. G., and Lane, F. D., 2010, Interpretation of AVO anomalies: Geophysics, 75, A3 - A13.
[7]
Goodway, W., Chen, T., and Downton, J., 1997, Improved AVO fluid detection and lithology discrimination using Lamé petrophysical parameters from P and S inversion: 67th Ann. Internat. Mtg., Soc. Expl. Geophys., Expanded Abstracts, 183 - 186.
[8]
Jiang, W., Li, L., and Zhao, J., 2010, Application of fluid identification with multi-parameter cross-plotting: Progress in Exploration Geophysics, 33(3), 189 - 195.
[9]
Li, X., and Zhang, Y., 2011, Seismic reservoir characterization: how can multicomponent data help?: Journal of Geophysics and Engineering, 8, 123 - 141.
[10]
Ma, J., 2003, Forward modeling and inversion methods based on generalized elastic impedance in seismic exploration: Journal of Chinese Geophysics, 46, 159 - 168.
[11]
Ma, J .F., and Morozov, I. B., 2007, The exact elastic impedance for P-SV wave: 77th Ann. Internat. Mtg., Soc. Explor. Geophys., Expanded Abstracts, 288 - 292.
[12]
Smith, G. C., and Gidlow, P. M., 1987, Weighted stacking for rock property estimation and detection of gas: Geophysical Prospecting, 35, 993 - 1014.
Yin, C., and Gu, H., 2008, The sensitivity analysis of AVO fluid factors: Chinese Journal of Engineering Geophysics, 5(1), 85 - 88.
[17]
Zhang, F., Wang, Y., and Li, X., 2012, Viabilities of seismic ray impedance and elastic impedance for hydrocarbon-sand discrimination: Geophysics, 77(4), M39 - M52.
[18]
Zheng, X., 1991, Relationships between converted and non-converted waves and parameter p: Chinese Journal of Geophysics, 34(6), 781 - 787.
[19]
Zhou, Y., and Li, X., 2010, Application of sensitive angle elastic impedance in fluid prediction: OGP, 45(5), 710 - 713.
2013, Vol. 10 
