Abstract：
Seismic inversion is one of the most widely used technologies for reservoir prediction. Many good results have been obtained but sometimes it fails to differentiate the lithologies and identify the fluids. However, seismic prestack elastic inversion based on rock physics modeling and analysis introduced in this paper is a significant method that can help seismic inversion and interpretation reach a new quantitative (or semi-quantitative) level from traditional qualitative interpretation. By doing rock physics modeling and forward perturbation analysis, we can quantitatively analyze the essential relationships between rock properties and seismic responses and try to find the sensitive elastic properties to the lithology, porosity, fluid type, and reservoir saturation. Finally, standard rock physics templates (RPT) can be built for specific reservoirs to guide seismic inversion interpretation results for reservoir characterization and fluids identification purpose. The gas sand distribution results of the case study in this paper proves that this method has unparalleled advantages over traditional post-stack methods, by which we can perform reservoir characterization and seismic data interpretation more quantitatively and efficiently.
HE Fu-Bang,YOU Jun,CHEN Kai-Yuan. Gas sand distribution prediction by prestack elastic inversion based on rock physics modeling and analysis[J]. APPLIED GEOPHYSICS, 2011, 8(3): 197-205.
[1]
Aki, K., and Richards, P. G., 1980, Quantitative seismology: Theory and methods: W. H. Freeman and Co., San Francisco.
[2]
Avseth, P., Mukerji, T., and Mavko, G., 2005, Quantitative seismic interpretation: Applying rock physics tools to reduce interpretation risk: Cambridge University Press, UK.
[3]
Castagna, J. P., Batzle, M. L., and Eastwood, R. L., 1985, Relationship between compressional-wave and shearwave velocities in clastic silicate rocks: Geophysics, 50, 571 - 581.
[4]
Castagna, J. P., Batzle, M. L., and Kan, T. K., 1993, Rock physics - The link between rock properties and AVO response: in Castagna J. P., and Backus, M., Eds., Offset-dependent reflectivity - Theory and practice of AVO analysis, Investigations in Geophysics, No.8, Soc. Explor. Geophys., 135 - 171.
[5]
Fatti, J. L., Smith, G. C., Vail, P. G., and et al., 1994, Detection of gas in sandstone reservoirs using AVO analysis: A 3-D seismic case story using the Geostack technique: Geophysics, 59, 1362 - 1376.
[6]
Gelfand, V., Ng, P., Nguyen, H., and Larner, K., 1986, Seismic lithologic modeling of amplitude-versus-offset data: 56th Ann. Internat. Mtg. Soc. Explor. Geophys., Expanded Abstracts, 334 - 336.
[7]
Gray, D., Goodway, W., and Chen, T., 1999, Bridging the gap: Using AVO to detect changes in fundamental elastic constants: 69th Ann. Internat. Mtg., Soc. Expl. Geophys., Expanded Abstracts, 852 - 855.
[8]
Greenberg, M. L., and Castagna, J. P., 1992, Shearwave velocity estimation in porous rocks: Theoretical formation, preliminary verification and applications: Geophysical Prospecting, 40, 195 - 210.
King, M. S., 2005, Rock-physics developments in seismic exploration：A personal 50-year perspective: Geophysics, 70(6), 3ND - 8ND.
[11]
Krief, M., Grant, J., Stellingwerff, J., and Ventre, J., 1990, A petrophysical interpretation using the velocities of P and S wave (full-waveform sonic): The Log Analyst, 31, 355 - 369.
Mavko, G., Mukerji, T., and Dvorkin, J., 2003, The rock physics handbook: Cambridge University Press, UK.
[14]
Oslash;degaard, E., and Avseth P., 2004, Well log and seismic data analysis using rock physics templates: First Break, 22, 37 - 43.
[15]
Raymer, L. L., Hunt, E. R., and Gardner, J. S., 1980, An improved sonic transit time-to-porosity transform: Soc. Professional Well Log Analysis (SPWLA), 21st Ann. Logg. Symp. Paper P.
[16]
Shuey, R. T., 1985, A simplification of the Zoeppritz equation: Geophysics, 50, 609 - 614.
Ye, T. R., Tang, J. M., and John T., 2009, Application of P wave and shear wave joint inversion for deeper tight gas prediction in west Sichuan basin: CPS/SEG Beijing 2009 International Geophysical Conference & Exposition.
2011, Vol. 8 
