Prestack density inversion using the Fatti equation constrained by the P- and S-wave impedance and density
Liang Li-Feng1,2, Zhang Hong-Bing1, Dan Zhi-Wei2, Xu Zi-Qiang2, Liu Xiu-Juan2, and Cao Cheng-Hao1
1. College of Earth Science & Engineering, Hohai University, Nanjing 210098, China.
2. CNOOC Energy Development Engineering Geophysical Prospecting Institute of Technology, Zhanjiang 524000, China.
Abstract：
Simultaneous prestack inversion is based on the modified Fatti equation and uses the ratio of the P- and S-wave velocity as constraints. We use the relation of P-wave impedance and density (PID) and S-wave impedance and density (SID) to replace the constant Vp/Vs constraint, and we propose the improved constrained Fatti equation to overcome the effect of P-wave impedance on density. We compare the sensitivity of both methods using numerical simulations and conclude that the density inversion sensitivity improves when using the proposed method. In addition, the random conjugate-gradient method is used in the inversion because it is fast and produces global solutions. The use of synthetic and field data suggests that the proposed inversion method is effective in conventional and nonconventional lithologies.
. Prestack density inversion using the Fatti equation constrained by the P- and S-wave impedance and density[J]. APPLIED GEOPHYSICS, 2017, 14(1): 133-141.
[1]
Aki, K., and Richards, P. G., 1980, Quantitative seismology: Theory and methods, Version 1. Freeman: W. H., Freeman and Co, 100-170.
[2]
Buland, A., and More, H., 2003, Bayesian linearized AVO inversion: Geophysics, 68(1), 185-198.
[3]
Castagna, J. P., Batzle, M. L., and Eastwood, R. L., 1985, Relationships between compressional and shear-wave velocities in clastic silicateocks: Geophysics, 50(2), 334-339.
[4]
Fang, Y., Zhang, F. Q., and Wang, Y. C., 2016, Generalized linear joint PP-PS inversion based on two constraints: Applied Geohysiss, 13(1), 103-115.
[5]
Fatti, J. L., Smith, G. C., Vail, P. J., et al., 1994, Detection of gas in sandstone reservoirs using AVO analysis: A 3-D seismic case history using the Geostacktechnique: Geophysics, 59(9),1362-1376.
[6]
Gardner, G. H. F., and Gregory, A. R., 1974, Formation velocity and density: the diagnostic basics for stratigraphic traps: Geophysics, 39(6), 770-780.
[7]
Hampson, D. P., Russell, B. H., and Bankhead, B., 2005, Simultaneous inversion of pre-stack seismic data: 75th Annual International Meeting, SEG, Expanded Abstracts, 1633-1636.
[8]
Huang, H. D., Wang, Y. C., and Guo, F., 2015, Zoeppritz equation-based prestack inversion and its application in fluid identification: Applied Geohysiss, 12(2),199-1211.
[9]
Lavaud, B., Kabir, N., and Chavent, G., 1999, Pushing AVO inversion beyond linearized approximation: Journal of Seismic Exploration, 8(3), 279−302.
[10]
Li, Y., 2005, A study on applicability of density inversion in defining reservoirs: 75th Annual International Meeting, SEG, Expanded Abstracts, 1646-1649.
[11]
Liang, L. F., Liu, X. J., and Dan, Z. W., 2011a, Application research on using pre-stack density inversion to predict lithology: Offshore oil, 31(2), 53−58.
[12]
Liang, L. F., Dan, Z. W., and Chen, J. F., 2011b, The Influence of Pre-stack Density Inversion Error on Gas Saturation Estimate: Chinese Journal of Engineering Geophysics, 8(3), 257−260.
[13]
Russell, B. H., Gray, D., and Hampson, D. P., 2011, Linearized AVO and poroelasticity: Geophysics, 76(3), C19-C29.
[14]
Wang, K., N., Sun, Z. D., and Dong, N., 2015, Prestack inversion based on anisotropic Markov random field-maximum posterior probability inversion and its application to identify shale gas sweet spots: Applied Geophysics, 12(4), 533−544.
[15]
Zhang, F. Q., Wei, F. J., Wang Y. C., et al., 2013, Generalized linear AVO inversion with the priori constraint of trivariate cauchy distribution based on Zoeppritz equation: Chinsese J. Geophys. (in Chinese), 2013, 56(6), 2098−2115.
[16]
Zhang, H. B., Shang, Z. P., and Yang, C. C., 2007, A non-linear regularized constrained impedance inversion: Geophysical Prospecting, 55, 819−833.
[17]
Zhu, P., M., Wang, J. Y., and Zhan, Z. B., 2004, Stochasitic conjugate gradient inversion: Oil Geophysical Prospecting, 35(2), 208−213.
[18]
Zoeppritz, K., and Erdbebnenwellen, V., 1919, On the reflection and penetration of seismic waves through unstable layers: Gottinger Nachrichten, 1, 66−84.
[19]
Zong, Z., Yin, X., and Wu, G., 2012, AVO inversion and poroelasticity with P- and S-wave moduli: Geophysics, 77(6), 29-36.
[20]
Zong, Z., 2013, Methodologies of model driven inversion with pre-stack seismic data: PhD Thesis, China University of Petroleum (Huadong), Qingdao.
2017, Vol. 14 
