角度域逆时偏移成像（ADRTM）方法及相关技术研究

发布时间：2018-04-05 11:01

本文选题：逆时偏移成像　切入点：角度域　出处：《东北石油大学》2016年博士论文

【摘要】：逆时偏移能够处理多路径、多次波、回转波、横向变速、高陡倾角地层以及倒挂地质结构等传统成像方法难以解决的问题而受到人们的广泛关注,地震波的角度域处理能够获得波的反射、散射等各种特性,有利于对地震成像、照明分析、成像校正、AVA分析、MVA等各种处理。本文主要对角度域逆时偏移成像及其相关问题开展了如下研究工作:1、在讨论传统RTM成像原理的基础上,分析了成像过程中低频噪声的产生机制。地震波的角度域处理由于其更加真实地反映成像过程中的不同波的影响,因而引起人们的重视。为提高波场的角度分解效率,文中采用了Poynting矢量方法。通过构建局部成像矩阵,分析不同角度的波对成像过程的影响,并利用角度滤波器滤除大角度反射波来抑制低波数噪声。2、基于双程波动方程的ADCIG是目前被认为没有任何运动学和动力学假象的、对偏移速度更加敏感的、并能真实反映地下介质AVA属性的道集。文中应用Poynting矢量来实现逆时偏移角道集的高效提取,并给出了具体实现方法及数值计算结果。3、地震照明分析对观测系统孔径、复杂的上覆构造及目标倾角等成像影响因素提供了有效的定量分析,是复杂构造及区域地震采集设计的有效手段。文中利用Poynting矢量对源及接收波场进行角度分解,并据此建立局部照明矩阵。该矩阵可以作为角度域照明分析的基础,包括了在目标附近所有可能的入射和散射方向对照明的贡献,通过研究入射和反射波在角度域中与反射面的相互作用,获得对地下结构的不同照明描述及采集倾角响应。文中对SEG模型进行了数值计算,在建立其局部照明矩阵的基础上,进行了照明分析及ADR计算。4、由于观测系统孔径、复杂的上覆构造及目标倾角等影响,偏移成像的结果实际上是对地下结构的一种扭曲成像,文中在照明分析的基础上,进一步研究RTM成像分辨及幅度校正问题。比较了几种幅度校正方法,并得出倾角域校正具有最好的校正效果。文中通过对偏移成像的数学过程,分析成像结果的扭曲因素,根据点弥散函数与ADR之间的关系,实现对成像过程的ADR计算,并对原始的RTM像进行局部傅里叶变换而得到共倾角像。利用计算的ADR及CDI实现对成像的补偿,不仅均衡了成像幅度,提高了成像质量,而且一定程度上抑制了成像噪声。另外由于ADR补偿假定在某个倾角的照明贡献是等效的,而PSF解卷积补偿不仅考虑倾角的影响,同时考虑了不同方向的散射强度因素,因此具有更好的成像补偿效果。文中在空间域嵌入扰动点计算PSF,然后进行PSF解卷积补偿,取得了良好的补偿效果。
[Abstract]:The reverse time migration can handle multiple paths, multiple wave, rotating wave, transverse speed, high steep dip and upside down the traditional geological structure imaging method is difficult to solve the problem and attention. The angle of seismic wave field to obtain wave reflection and scattering characteristics, is conducive to the seismic imaging, lighting analysis of image correction, AVA analysis, MVA and other treatment. Migration and related issues in this paper angle domain inverse carried out research work as follows: 1. Based on the traditional RTM imaging principle, imaging mechanism analysis of low frequency noise in the process. The angle of seismic wave field due to its more reflect the imaging process of different wave effects, which attracted people's attention. As the decomposing efficiency of wave field angle, this paper uses Poynting vector method. By constructing local imaging matrix, Analysis of the influence of different angles of the wave on the imaging process, and using the angle filter to remove the large angle reflection wave suppression low frequency noise.2, two-way wave equation based on ADCIG is now considered to have no illusion of kinematics and dynamics, more sensitive to migration velocity, and can reflect the real underground medium AVA attribute application gathers. Poynting vector to achieve efficient extraction of RTM angle gathers in the paper, and gives the concrete realization method and the numerical results of.3 analysis on observation system of seismic illumination aperture, provides an effective quantitative analysis on factors of nappe and target angle imaging complex, complex structure and regional seismic acquisition design effective means. The source and receiving wave field vector angle decomposition using Poynting in this paper, and then build local lighting matrix. The matrix can be used as illumination points in angle domain On the foundation, including near the target, all the possible direction of incident and scattering contribution to the lighting, through the study of the incident and reflected wave in the angle domain and reflection of the interaction of different lighting description of the underground structure and acquisition dip response. The SEG model was numerically calculated based on the local lighting matrix, the analysis and calculation of.4 ADR lighting, because the observation system on the aperture, nappe and target angle complex, migration imaging result is actually a distortion of the imaging of the underground structure, based on the illumination analysis, further study of RTM imaging resolution and amplitude correction problem. Comparing the amplitude correction method, and obtains the inclination correction with the best correction effect. The mathematical process of migration in this paper through the distortion factor analysis imaging results, according to the point The relationship between the diffusion function and ADR, realize the imaging process of ADR, and the original RTM like local Fu Liye transform and common dip angle image imaging for compensation. Using ADR and CDI calculation, not only the balance of the imaging range, improve the image quality, but also can restrain the imaging noise. In addition due to the contribution of ADR lighting in a certain angle compensation assumption is equivalent, and PSF deconvolution compensation not only consider the angle of influence, while taking into account the scattering intensity factors in different directions, so it has better imaging compensation effect. In this paper, the PSF calculation in spatial domain embedding disturbance, then PSF deconvolution to obtain compensation. A good compensation effect.

【学位授予单位】：东北石油大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：P631.4

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