The exploitation of thin-bedded and thin-interbedded hydrocarbon reservoirs has garnered increasing attention.However,seismic data of thin-bedded reservoirs exhibit low resolution,and conventional convolution models fail to simulate the complex wave field propagation phenomena in thin-bedded reservoirs,complicating the seismic prediction of such reservoirs.Hence,based on the transfer matrix method for layered media,this study developed a normal-incidence reflectance method.Using the new method,it conducted forward modeling on several typical thin-interbedded reservoir models.Then,the forward modeling results were analyzed through frequency spectrum analysis to explore the filtering effects of thin-interbedded reservoirs on seismic reflection waves.Compared to the transfer matrix method for layered media,the normal-incidence reflectance method is more applicable to the investigation of thin-interbedded reservoirs under longitudinal wave incidence,significantly enhancing the forward modeling efficiency.Moreover,studying the reflection filtering effects of thin-interbedded reservoirs in the frequency domain somewhat eliminates the shortcomings of insufficient resolution in the time domain.The frequency spectrum analysis of thin-interbedded reservoir models shows that the normal-incidence reflectance method can effectively preserve the interbed information of thin-interbedded reservoirs.As revealed by the frequency spectrum analysis of the forward modeling results based on this method,the changes in the amplitudes and notch points of frequency spectrum curves can reflect the changes in the number of interbeds and sandstone-mudstone ratios in thin-interbedded reservoirs.This finding is critical for determining the spatial distributions and properties of thin-bedded reservoirs in the fine-scale exploration of oilfields.
罗敬, 孙成禹. 基于模型的薄互层地震反射滤波效应研究[J]. 物探与化探, 2024, 48(4): 996-1005.
LUO Jing, SUN Cheng-Yu. A model-based study of the filtering effects of thin-interbedded reservoirs on seismic reflection waves. Geophysical and Geochemical Exploration, 2024, 48(4): 996-1005.
Ricker N. Wavelet contraction,wavelet expansion,and the control of seismic resolution[J]. Geophysics, 1953, 18(4):769.
[2]
Sengbush R L, Lawrence P L, McDonal F J. Interpretation of synthetic seismograms[J]. Geophysics, 1961, 26(2):138-157.
[3]
Widess M B. How thin is a thin bed?[J]. Geophysics, 1973, 38(6):1176-1180.
[4]
Kallweit R S, Wood L C. The limits of resolution of zero-phase wavelets[J]. Geophysics, 1982, 47(7):1035-1046.
[5]
Thomson W T. Transmission of elastic waves through a stratified solid medium[J]. Journal of Applied Physics, 1950, 21(2):89-93.
[6]
Fuchs K. The reflection of spherical waves from transition zones with arbitrary depth-dependent elastic moduli and density[J]. Journal of Physics of the Earth, 1968, 16:27-41.
[7]
Fuchs K, Müller G. Computation of synthetic seismograms with the reflectivity method and comparison with observations[J]. Geophysical Journal International, 1971, 23(4):417-433.
[8]
Mueller G. The reflectivity method:A tutorial[J]. Journal of Geophysics, 1985, 58(1):153-174.
[9]
Kennett B L N. Seismic waves in laterally inhomogeneous media[J]. Geophysical Journal International, 1972, 27(3):301-325.
[10]
Kennett B L N, Kerry N J. Seismic waves in a stratified half space[J]. Geophysical Journal International, 1979, 57(3):557-583.
[11]
Kennett B L N. Seismic waves in a stratified half space—II.Theoretical seismograms[J]. Geophysical Journal International, 1980, 61(1):1-10.
[12]
Kennett B L N, Illingworth M R. Seismic waves in a stratified half space—III.Piecewise smooth models[J]. Geophysical Journal International, 1981, 66(3):633-675.
[13]
Kennett B. Seismic wave propagation in stratified media[M]. Canberra: ANU Press, 2009.
[14]
Phinney R, Odom R, Fryer G. Rapid generation of synthetic seismograms in layered media by vectorization of the algorithm[J]. Bulletin of the Seismological Society of America, 1987, 77:2218-2226.
[15]
Carcione J M. Wave fields in real media[M]. Oxford: Elsevier, 2001.
Yang K, Lei X. A new method for calculating the thickness and reflection coefficient of thin layer in frequency domain[J]. Journal of Southwest Petroleum University:Science & Technology Edition, 1993, 15(S1):73-75.
Shao Z L, He Z H, Huang D J. Thin-layer thickness estimation using wavelet transform and maximum entropy method[J]. Oil Geophysical Prospecting, 1998, 33(2):204-213.
[19]
蒋龙聪. 薄互层储层地震响应时频分析研究[D]. 武汉: 中国地质大学, 2008.
[19]
Jiang L C. The method of time-frequency analysis applied in thin interbedded reservoir[D]. Wuhan: China University of Geosciences, 2008.
[20]
张晶. 薄互层时频变化规律正演模拟研究[D]. 大庆: 东北石油大学, 2013.
[20]
Zhang J. Forward modeling studies on the time-frequency transform law of thin interbed[D]. Daqing: Northeast Petroleum University, 2013.
Ma Y H, Zhou Z L, Li Z Y, et al. Classification and seismic response analysis of thin bed:Two cases study from Dagang oilfield,China[J]. Geophysical Prospecting for Petroleum, 2018, 57(6):902-913.
doi: 10.3969/j.issn.1000-1441.2018.06.013
Li J X, Yang C, Wang Y. A state of the art on the equivalent anisotropy of thin interbeds[J]. Geophysical Prospecting for Petroleum, 2021, 60(2):224-237.
Ni C K, Su M J, Yuan C, et al. Thin-interbedded reservoirs prediction based on seismic sedimentology[J]. Petroleum Exploration and Development, 2022, 49(4):741-751.
Yang Z, Liu J Z, Shi L, et al. Application of AVA inversion technique based on rapid reflectivity method in thin tight gas reservoir exploration[J]. Geophysical Prospecting for Petroleum, 2023, 62(1):130-141.
doi: 10.3969/j.issn.1000-1441.2023.01.011
Sun C Y, Wan X J, Ni C K. Forward modeling of reflected wavefield from strata with weakly bonded interfaces[J]. Geophysical Prospecting for Petroleum, 2007, 46(5):425-432,13.
