基于行波分离的三维弹性波矢量场点积互相关成像条件

发布时间：2018-04-22 01:03

本文选题：行波分离 + 矢量波场点积互相关成像　；参考：《石油地球物理勘探》2017年03期

【摘要】：针对传统三维弹性波逆时偏移方法存在横波合成不准确的难题,提出基于行波分离的矢量波场点积互相关成像条件。首先利用传统波场分离方法获得标量纵波和矢量横波;再对波场分离得到的标量纵波求取梯度获得矢量势纵波,对矢量横波求取旋度得到矢量势横波;然后求取弹性波场的坡印廷矢量并据此对矢量势纵横波进行分解,分别得到上、下、左、右、前、后行波;最后将炮点分解得到的上、下、左、右、前、后矢量纵、横波分别与接收点分解得到的下、上、右、左、后、前矢量纵、横波对应做点积互相关,得到炮点纵波接收点纵波偏移剖面、炮点纵波接收点转换横波偏移剖面、炮点转换横波接收点纵波偏移剖面和炮点转换横波接收点转换横波偏移剖面。该成像方法理论上可以消除逆时偏移产生的低频噪声,且无需对转换横波偏移剖面做极性校正;模型算例证明了算法的准确性和有效性。
[Abstract]:In order to solve the problem of inaccurate transverse wave synthesis in the traditional three dimensional elastic wave inverse time migration method, the imaging condition of vector wave field point product cross correlation based on traveling wave separation is proposed. First, the traditional wave field separation method is used to obtain the scalar longitudinal wave and vector transverse wave, and the vector potential longitudinal wave is obtained by the gradient of the scalar wave obtained by the wave field separation. The vectorial wave is obtained by the volume shear wave, and then the vectoring vector of the elastic wave field is obtained and then the vector potential longitudinal transverse wave is decomposed to get the upper, lower, left, right, front and back waves respectively. Finally, the upper, the left, right, the front, the rear vector longitudinal and the transverse waves are decomposed into the upper, right, left, back, and the front vectors respectively. The transverse wave corresponds to the cross correlation of point product, and the longitudinal wave offset section of the longitudinal wave receiving point of the gun point is obtained, the P-wave receiving point of the gun point is converted to the cross wave offset section, the gun point transversal wave receiving point longitudinal wave offset section and the gun point conversion cross wave receiving point converts the transverse wave offset section. This imaging method can theoretically eliminate the low frequency noise produced by the reverse time migration. There is no need to make polar correction for the converted shear wave migration profile; the model calculation example proves the accuracy and effectiveness of the algorithm.

【作者单位】：海底科学与探测技术教育部重点实验室;青岛海洋科学与技术国家实验室海洋矿产资源评价与探测技术功能实验室;中国海洋大学;
【基金】：国家自然科学基金项目(41674118) 国家科技重大专项(2016ZX05027-002)资助
【分类号】：P631.4

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