小波域叠前地震资料衰减参数定性估计方法  

Qualitative estimation of seismic attenuation parameters based on pre-stack data in the wavelet domain

作　　者：吴丹[1] 陈文超[1,2,3] 王晓凯[1,4,2,3] 高磊[1,2] 高静怀[1,4,2,3] 

机构地区：[1]西安交通大学波动与信息研究所,西安710049 [2]海洋石油勘探国家工程实验室,西安710049 [3]北京数学与信息交叉科学协同创新中心油气勘探与开发平台,西安710049 [4]西安交通大学计算地球物理科学系,西安710049

出　　处：《地球物理学报》2016年第7期2674-2683,共10页Chinese Journal of Geophysics

基　　金：国家自然科学基金(41390454;41274125;41504092)资助

摘　　要：叠前地震资料中,高频分量和低频分量随传播距离的衰减特性不同.本文给出了一种在小波域定性估计叠前地震资料衰减参数的方法.该方法利用连续小波变换提取共反射点道集的高、低频分量,以低频分量和高频分量之差定性反映地震波的衰减.通过累加不同偏移距的衰减,提高了估计的稳定性;采用幅度归一化方法,降低了信号幅值对衰减参数估计的影响.将本文提出方法与常用的基于叠后地震资料衰减估计方法用于某油田的地震资料处理,结果表明,本文方法得到的衰减估计结果能够更好地反映油气的空间展布.In seismic wave propagation, the high-frequency component and low-frequency component have different attenuating properties with propagating distance, especially in strong attenuating areas. Many time-frequency analyzing tools are used to extract high-frequency component and low-frequency component of stacked seismic data to characterize attenuation quantitatively or qualitatively. However, the stacking operation on pre-stacked seismic data would affect characterizing precision seriously. In order to improve precision and robustness, we propose a qualitative attenuation estimating method for pre-stack seismic data with the help of continuous wavelet transform. This method uses continuous wavelet transform to extract the high-frequency component and low-frequency component from the common reflection point gather data, and adopts the modified best matching seismic wavelet as mother wavelet. The difference between low-frequency component and high-frequency component is used to reflect seismic attenuationqualitatively. The summation of attenuation along offset is adopted to enhance the robustness of estimation, while the amplitude normalization is adopted to reduce the affection of amplitude. The proposed method is applied to a field data which contains 901 CRP gathers. Two wells are located in this area. The results show that the proposed method obtains a seismic attenuation parameter section which accords with drilling results very well. The qualitative seismic attenuation estimating method based on stacked data is also applied to a field data. Compared with the method based on stacked data, the proposed method has better anti-noise ability and is less likely to be affected by amplitude.

关 键 词：地震衰减 小波变换 共反射点道集 

分 类 号：P631.443[天文地球—地质矿产勘探]