Adaptive Focused Beam Prestack Depth Migration Under the Condition of Rugged Topography
Adaptive Focused Beam Prestack Depth Migration Under the Condition of Rugged Topography
复制标题
DOI：
10.1109/tgrs.2023.3271389
复制
发表时间：
2023
影响因子：
8.2
通讯作者：
Jianguang Han;Qingtian Lü;B. Gu;Zhantao Xing
中科院分区：
文献类型：
--
作者：
Jianguang Han;Qingtian Lü;B. Gu;Zhantao Xing
复杂地形是陆上地震勘探中的一个难题。地形起伏和近地表速度的横向变化对地震数据的精确成像构成了重大障碍。自适应聚焦波束偏移方法保留了射线方法在复杂地表条件下计算地震波场的良好适用性。它可以有效地解决传统高斯波束偏移中深、浅地层成像精度之间的矛盾。本文将自适应聚焦波束偏移方法推广到复杂地表条件下地震资料的深域成像。首先，回顾了自适应聚焦光束的基本原理。在此基础上，利用自适应聚焦波束表征了起伏地形下震源和接收点的绿色函数，提出了一种基于互相关成像的自适应聚焦波束叠前深度偏移方法。采用全波至成像策略对地下成像点的所有波至进行成像。采用单输入地震道成像，可直接从起伏地形的接收点发射聚焦波束进行波场延拓，避免了多次聚焦。结果表明，该偏移方法对复杂地表条件的适用性得到了提高，成像精度也得到了有效提高。不同起伏地形条件和构造形式的数值模型偏移试验表明，该方法是一种有效的叠前深度偏移方法，适用于起伏地形条件下的地震资料精确成像。
Complex topography is a challenging issue in onshore seismic exploration. The rugged terrain and lateral change of near-surface velocity pose a significant obstacle to the accurate imaging of seismic data. The adaptive focused beam migration method retains the good applicability of the ray methods for calculating the seismic wavefield under complex surface conditions. It can effectively solve the contradiction between the imaging accuracy of deep and shallow strata in traditional Gaussian beam migration. We extend the adaptive focused beam migration approach to the deep domain imaging of seismic data under complex surface conditions. First, the basic principles of the adaptive focused beam are reviewed. Then, Green’s functions of the seismic source and the receiving point of rugged topography are characterized by the adaptive focused beam, and an adaptive focused beam prestack depth migration method based on cross correlation imaging is proposed. The full-wave-arrival imaging strategy is applied to image all wave arrivals of subsurface imaging points. A single input seismic trace is adopted for imaging, which can directly emit the focused beam from the receiving point of rugged topography for wave field continuation, thus avoiding multiple focusing. As a result, the applicability of the migration approach to complex surface conditions was improved, and the imaging accuracy of the migration method was also effectively enhanced. The numerical model migration test of different rugged topography conditions and tectonic forms verified that the proposed method was an effective prestack depth migration applicable to accurately imaging seismic data under the rugged topography condition.