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矢量波成像能够充分利用弹性波场信息,可获得更可靠、更准确的成像结果.本文对TTI介质多分量资料进行矢量波逆时偏移成像处理,从各向异性介质弹性波动理论出发,通过高阶交错网格差分对弹性波方程离散化处理,并将震源波场和检波点波场沿时间方向延拓,再基于局部介质性质求解Christoffel方程,然后将延拓波场沿极化矢量方向投影,得到TI介质中分离的纵横波场,以上述结果作为逆时偏移互相关成像条件中的分量,实现二维多分量地震资料的矢量波叠前逆时偏移,最终得到物理意义明确的P-P和P-SV成像结果.模型试算表明在TTI介质中采用极化投影法分离纵横波场,比基于散度和旋度的分离方法效果更彻底,此外通过算例验证了基于纵横波分解的矢量波成像是一种有效的矢量波场处理技术,成像结果显示该方法获得的信息更丰富,成像更准确.
Vector wave imaging can make full use of the elastic wave field information to obtain more reliable and accurate imaging results.In this paper, vector wave inverse time migration imaging processing of multi-component data of TTI media is carried out. Based on the theory of elastic wave propagation in anisotropic media, High-order staggered grid differential elastic wave equation discretization processing, and the source wavefield and the wavefield of the detection point to extend along the time direction, and then based on the local media properties to solve the Christoffel equation, and then the continuation wavefield along the direction of the polarization vector And the longitudinal and transverse wave fields separated in the TI medium are obtained. The above results are used as the components in the inverse time-migration cross-correlation imaging conditions to realize the pre-stack inverse-time migration of the 2D multi-component seismic data, PP and P-SV imaging results.The model test shows that the separation of longitudinal and transverse wave fields by polarization projection in TTI media is more thorough than the separation method based on divergence and curl. In addition, Decomposition of vector wave imaging is an effective vector wave field processing technology, imaging results show that the method to obtain richer information, imaging more accurately.