Document Type : Research Paper
Authors
1 Department of Petroleum Exploration, Petroleum University of Technology, Abadan, Iran
2 Institute of Geophysics, University of Tehran, Tehran, Iran
Abstract
Seismic inversion is a method that extracts acoustic impedance data from the seismic traces. Source wavelets are band-limited, and thus seismic traces do not contain low and high frequency information. Therefore, there is a serious problem when the deterministic seismic inversion is applied to real data and the result of deterministic inversion is smooth. Low frequency component is obtained from well log data; however, but when well log and seismic data are used together, it faces a problem which is a function of the support of scale of measurements. Well log data have a high vertical resolution while seismic data represent low details in vertical direction. Geostatistical seismic inversion (GSI) is a method to overcome the aforementioned limitations. GSI uses well log and seismic data together in the geostatistical frameworks. In this study, a new approach of geostatistical inversion based on spectral geostatistical simulation is used. This approach is performed in frequency domain and stochastic framework. Distinct from sequential simulation, spectral simulation method is a direct method, which does not require an acceptance/rejection step. Hence, GSI algorithm based on spectral simulation is fast. This approach is performed in a case study of an Iranian gas field in the Persian Gulf basin. The upper-Dalan and Kangan are two main formations of this field. The results of GSI are compared with deterministic inversion and it is concluded that, as opposed to deterministic inversion, GSI can recover low frequency components.
Keywords
Geophysics, Vol. 48, No. 6, p. 665-676, 1983.
Deutsch, C. V. and Journel, A. G., GSLIB-Geostatistical Software Library and User's Guide, Oxford
University Press, New York, 338 p,1992.
Edgar, J. A. and Van der Baan, M., How Reliable is Statistical Wavelet Estimation?, Geophysics, Vol.
76, No. 4, p. V59-V68, 2011.
Francis, A., Limitations of Deterministic and Advantages of Stochastic Seismic Inversion, Paper
Presented at the Canadian Society of Exploration Geophysicists, Telus Convention Centre,
Calgary, 2005.
Francis, A., Understanding Stochastic Inversion: Part 1, First Break, Vol. 24, No. 11, p. 69-77, 2006.
Francis, A, Limitations of Deterministic Seismic Inversion Data as Input for Reservoir Model
Conditioning, Paper Presented at the SEG Annual Meeting, Denver, Colorado, 2010.
Grijalba-Cuenca, A. and Torres-Verdín, C., Geostatistical Inversion of 3D Seismic Data to
Extrapolate Wireline Petrophysical Variables Laterally away from the Well, Paper Presented at
the SPE Annual Technical Conference and Exhibition, Dallas, Texas, 2000.
Modeling Constrained by Seismic Data, First Break, Vol. 12, No. 11, p. 561-569, 1994.
Kelkar, M. and Perez, G., Applied Geostatistics for Reservoir Characterization, 264 p. SPE
Publications, 2002.
Lancaster, S. and Whitcombe D., Fast-Track “Colored” Inversion, 70th SEG Annual Meeting, SEG
Expanded Abstracts 19, SEG 2000-1572, 2000.
Merletti, G., Hlebszevitsch, J., and Torres-Verdín, C., Geostatistical Inversion for the Lateral
Delineation of Thin-layer Hydrocarbon Reservoirs: A Case Study in San Jorge Basin,
Argentina; SEG Annual Meeting, Dallas, Texas, October 26-31, 2003.
Tavakoli, V., Rahimpour-bonab, H., and Esrafili-dizaji, B., Diagenetic Controlled Reservoir Quality
of Pars Gas Field: An Integrated Approach, Comptes Rendus Geoscience, Vol. 343, p. 55-71,
2011.
Yao, T., Calvert, C., Bishop, G., Jones, T., Ma, Y., and Foreman, L., Spectral Component Geologic
Modeling: A New Technology for Integrating Seismic Information at the Correct Scale, Eds: O.
Leuangthong, O., and Deutsch, C. V., Geostatistics Banff, Vol. 1, p. 23-33, Printed in the
Netherlands: Springer, 2004.
Zhang, R., Sen, M. K., Phan, S., and Srinivasan, S., Stochastic and Deterministic Seismic Inversion
Methods for Thin-bed Resolution, Journal of Geophysics and Engineering, Vol. 9, No. 5, p.
611-18, 2012.
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