近地表地震散射噪声的正反演方法

Forward and inverse method for near surface seismic scattered noises

1. 成都理工大学，四川成都610059;2. 江苏油田物研院，江苏南京210046

1. Chengdu University of Science and Technology, Chengdu 610059, China;2. Geophysical Prospecting Research Institute of Jiangsu Oilfield Company, Nanjing 210046, China

假设近地表垂直点力产生的地震波场由入射波场和散射波场组成,散射波场是入射波场与波阻抗差函数的函数。在这样的模式下,通过在平行地表的一个网格面的各个节点上,设置波阻抗差函数来近似地表的非均匀性,可以正演模拟出近地表地震散射噪声,也可以通过炮集纪录反演出近地表地震散射噪声,从而实现近地表地震散射噪声的衰减,提高地震资料的信噪比。

The seismic wave field, which is produced by vertical point forces in the near surface, is supposed to consist of incident wave field and scattered wave field, and the scattered wave field is assumed to be a function of incident wave field and acoustic impedance difference. In this case, near surface seismic scattered noises can be stimulated by designing a function of acoustic impedance difference for each node in the grid, which is parallel to surface, to approximate to the heterogeneity of surface. Near surface seismic scattered noises can also be inverted using shot gather, thus it can be attenuated to improve signal-to-noise ratio of the seismic data.