复杂构造叠前逆时偏移成像方法研究

发布时间：2018-03-27 05:31

本文选题：逆时偏移　切入点：波场模拟　出处：《东北石油大学》2015年硕士论文

【摘要】：地震资料成像是获取地下构造信息的重要手段,叠前逆时偏移方法是目前公认的成像精度最高的偏移方法,其基于双程波方程,不受地下构造倾角的限制,可对绕射波、回转波以及多次波等复杂地震波场进行成像。但是该方法本身计算成本高、低频噪音严重、内存需求大、波场模拟边界条件和地震波频散抑制尚待深化研究。针对上述问题,本文开展了波场模拟有限差分差分系数优化、地震波频散分析、GPU(图形处理器)加速逆时偏移、随机边界条件、PML有效边界存储、拉普拉斯低频噪音压制、数据测试以及Qt界面集成等方面的研究。本文主要取得以下进展:(1)本文从地震波场数值模拟入手,研究优化差分系数的有限差分数值模拟方法,研究了影响数值频散的主要因素,分析了地震波场数值计算的稳定性;(2)从GPU和CPU协同并行计算入手,研究了CPU/GPU协同并行加速技术,实现了地震波场数值模拟和逆时偏移的加速算法,大幅度提高了计算效率;(3)研究并对比分析了随机边界条件和节约存储的PML有效边界存储方法,在有效压制边界干扰的情况下,极大地降低了波场存储量,给出了随机边界方法和有效边界存储方法适用条件及范围。(4)研究了拉普拉斯低频噪音压制方法,有效地压制了逆时偏移的低频噪音;(5)本文进行了大量的数据测试和分析,分别对Marmousi模型、Sigsbee 2A模型、2D Salt模型、BP2004模型、字母模型、深层断裂模型、断陷盆地模型、碳酸盐岩模型以及实际数据进行逆时偏移计算。(6)研究了Qt界面集成技术,将地震波场数值模拟和叠前逆时偏移算法进行了界面封装和优化,形成了快捷、实用性强的友好界面。本文针对逆时偏移现存的问题开展研究,提出了切实可行的实施方案,并进行了大量的数据测试和分析,推动了叠前逆时偏移方法的理论研究和实用化进程。
[Abstract]:Seismic data imaging is an important means to obtain the information of underground structures. The prestack inverse time migration method is currently recognized as the most accurate migration method. It is based on the two-way wave equation and is not restricted by the dip angle of underground structures, so it can be applied to diffraction waves. The complex seismic wave fields, such as rotational waves and multiple waves, are imaged. However, the method itself has the advantages of high computational cost, serious low frequency noise and large memory requirement. The boundary conditions of wave field simulation and the suppression of seismic wave dispersion need to be further studied. In this paper, the finite difference coefficient optimization of wave field simulation, seismic wave dispersion analysis, GPU accelerated inverse time migration, stochastic boundary condition PML efficient boundary storage, Laplace low frequency noise suppression are carried out. Research on data testing and QT Interface Integration. In this paper, the following progress has been made: 1) in this paper, the finite difference numerical simulation method to optimize the difference coefficient is studied from the seismic wave field numerical simulation. The main factors affecting numerical dispersion are studied, and the stability of numerical calculation of seismic wave field is analyzed. The cooperative parallel acceleration technique of GPU and CPU is studied based on the cooperative parallel computation of CPU/GPU and CPU. The numerical simulation of seismic wave field and the acceleration algorithm of inverse time migration are realized. The computational efficiency is greatly improved. The stochastic boundary conditions and the saving storage PML efficient boundary storage method are compared and analyzed. When the boundary interference is suppressed effectively, The storage capacity of wave field is greatly reduced. The suitable conditions and range of stochastic boundary method and effective boundary storage method are given. The Laplace low frequency noise suppression method is studied. A large number of data are tested and analyzed in this paper. The Marmousi model, Sigsbee 2A model, 2D Salt model, BP2004 model, alphabetic model, deep fault model, fault basin model, etc. The integration technology of QT interface is studied in carbonate rock model and actual data. The seismic wave field numerical simulation and prestack inverse time migration algorithm are encapsulated and optimized. This paper studies the existing problems of inverse time migration, puts forward a feasible implementation plan, and carries out a lot of data testing and analysis. It promotes the theoretical research and practical process of prestack inverse time migration.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P631.4

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