论文部分内容阅读
高斯束叠前深度偏移是对地下介质进行精确成像的方法之一,多分量地震资料的叠前深度偏移技术可以对复杂构造进行更准确的成像。由于实际地下介质具有粘滞性,研究粘弹性叠前深度偏移具有一定的现实意义。本文采用高斯束偏移方法对多分量地震数据进行吸收衰减补偿,首先利用高斯束模拟粘弹性介质中传播的地震波,并在模拟中引入与品质因子Q有关的复速度和精确的粘弹性Zoeppritz方程,合成地震记录;然后给出纵波和转换波共炮域高斯束叠前深度偏移原理,在此基础上推导补偿吸收衰减的表达式,校正Q引起的振幅衰减和相位畸变,实现基于吸收衰减补偿的多分量高斯束叠前深度偏移,并分析Q误差对偏移结果的影响。数值实验表明,在考虑地下介质的粘滞性时,本文方法具有更高的成像分辨率。
The prestack depth migration of Gaussian beam is one of the methods of accurately imaging the underground media. The prestack depth migration of multi-component seismic data can make the imaging of complex structures more accurate. Due to the viscosity of the actual underground medium, it is of practical significance to study the viscoelastic prestack depth migration. In this paper, the Gaussian beam migration method is used to compensate the attenuation of the multi-component seismic data. First, the Gaussian beam is used to simulate the seismic wave propagating in the viscoelastic medium. The complex velocity and accurate viscoelastic Zoeppritz equation , Then synthetic seismograms are recorded. Then, the principle of Gaussian prestack depth migration of P-wave and converted waves is given. Based on this, the expression of compensation absorption attenuation is deduced, and the amplitude attenuation and phase distortion caused by Q are corrected. Compensated multi-component Gaussian beam prestack depth migration, and analyze the effect of Q error on the offset results. Numerical experiments show that the proposed method has higher imaging resolution when considering the viscosity of underground media.