Kirchhoff积分叠前时间偏移全方位角度道集生成方法与实现  

Kirchhoff Integral Prestack Time Migration with Full Azimuth Angle Gathers Generation Method and its Implementation

作　　者：欧阳敏 刘守伟 李列 王大为 OUYANG Min;LIU Shou-wei;LI Lie;WANG Da-wei(China National Offshore Oil Zhanjiang Branch,Zhanjiang 524057,China;Shanghai Qingfeng Zhiyuan Geophysics & Geology Exploration Co.LTD, Shanghai 200093,China)

机构地区：[1]中国海洋石油湛江分公司,广东湛江524057 [2]上海青凤致远地球物理地质勘探科技有限公司,上海200093

出　　处：《CT理论与应用研究（中英文）》2018年第6期739-747,共9页Computerized Tomography Theory and Applications

基　　金：国家"十三五"重大专项"琼东南盆地深水区大中型气田形成条件与勘探关键技术"(2016ZX05026-02)

摘　　要：方位角度域共成像点道集能够客观反映地下介质的速度、各向异性参数异常以及振幅随角度变化(AVA)和裂缝信息。传统Kirchhoff PSTM通常输出偏移距域共成像点道集,对于速度分析、各向异性分析、AVA分析、裂缝识别等均存在诸多不便。本文提出了基于走时梯度的Kirchhoff叠前时间偏移全方位角度集输出方法并提出工业上切实可行的实现方案。通过走时场梯度计算波场传播方向矢量,形成能够反映观测系统参数和波场传播情况的全方位角度域共成像点道集。为了在大规模地震数据Kirchhoff积分叠前时间偏移中输出全方位角度道集,本文给出基于输入道方式的偏移实现方法,采用逐条inline线进行线偏移成像,从而大大降低了全方位角度道集输出对计算机内存的压力,显著提高了Kirchhoff积分时间偏移输出全方位角度道集的可行性。三维盐丘模型测试和海上某区块三维实际资料试验证明了本文方法的正确性。The azimuth angle domain common image gathers can objectively reflect the velocity, anisotropy parameter anomaly and amplitude versus angle(AVA) and fracture information of the subsurface medium. The traditional Kirchhoff PSTM usually outputs offset domain common image gathers, which have many inconveniences for velocity analysis, anisotropy analysis, AVA analysis, and fracture identification. This paper proposes a Kirchhoff pre-stack time migration with full azimuth angle gathers output method based on travel timegradient and proposes an industrially feasible implementation. The wave field propagation direction vector is calculated by the travel time field gradient to form full azimuth angle gathers, which can reflect seismic acquisition parameters and wave fields propagation effect. In order to process large-scale seismic data, this paper gives a practical strategy, which bases on input-imaging point. Imaging subsurface inline-by-inline, which greatly reduces the total the pressure of the azimuth angle gather output on the computer memory, and greatly improves the feasibility of the Kirchhoff integral time migration with full azimuth angle gathers output. The three-dimensional SEG salt model data and real data test in a certain offshore dataset proves the correctness of the method.

关 键 词：Kirchhoff时间偏移 方位角度道集 输入道 并行实现 

分 类 号：P631[天文地球—地质矿产勘探]