Abstract:Based on three-layer bi-interface thin layer model the theoretical relationship formula between seismic peak frequency and thickness was derived in this paper, the wavelet categories, the wavelet phase and the wavelet peak frequency's impact on the relation between thin layer peak frequency's and its thickness were also discussed, based on the studies the templates of thin layer peak frequency and its thickness for reflection coefficient combination of different tops and bottoms were established,the general rule for seismic peak frequency's change with thin layer's thickness was summarized, as a result the new idea for picking up thin layer's thickness was developed, and at last the following understandings were achieved: (1). different wavelet causes different frequency variation characteristics for thin layer tuning, that is, the higher the wavelet's peak frequency, the more obvious for frequency variation of the thin layer, however the wavelet's phase does not affect the seismic peak frequency variation which the thin layer causes, (2). within tuning thickness the peak frequencies of the rhythm thin layers are always larger than the incidence wavelet's peak frequency, while the peak frequencies of the progressive thin layers are always smaller than the incidence wavelet's peak frequency. (3). for all thin layers, seismic peak frequency's decrease with their thickness is not monotonic, that is, when the reflection coefficient of the top of the thin layer and the reflection coefficient of the bottom of the thin layer have different signs, the degree of the seismic peak frequency's decrease with their thickness firstly goes up and then goes down, but when they have the same signs, the degree of the seismic peak frequency's decrease with their thickness almost always goes up gradually, and (4). The curves for relationship between thin layers' seismic peak frequency and their thicknesses for all reflection coefficient combinations compose a curve sets on the template, and the ratio of top reflection coefficient and bottom reflection coefficient shows regular variation, that is, for a single thin layer with a known ratio, its thickness can be directly read from the corresponding template.
孙鲁平, 郑晓东, 首皓, 李劲松, 李艳东. 薄层地震峰值频率与厚度关系研究[J]. 石油地球物理勘探, 2010, 45(2): 258-259,271.
Sun Lu-ping, Zheng Xiao-dong, Shou Hao, Li Jing-song, Li Yan-dong. The studies on relationship between thin layer seismic peak frequency and its thickness. OGP, 2010, 45(2): 258-259,271.