【作者】 周振晓；

【导师】 张军华；

【作者基本信息】 中国石油大学 ， 地球探测与信息技术， 2008， 硕士

【摘要】 多次波压制一直是地震资料处理非常关注的工作。多次波的存在,降低了地震资料的分辨率,干扰了人们对有效波的识别,同时严重影响了地震资料的处理质量。因此如何有效的消除或衰减各种类型的多次波,并最大限度的保留一次波信号是地震勘探中的一个重要课题。基于波动方程理论压制多次波,综合考虑了多次波传播的运动学特性和动力学特性,避免了非波动法解决问题所带来的局限性。由于波动法几乎不需要先验信息和具有较好的应用效果,已经成为多次波研究的重要发展趋势。本文首先系统的介绍了多次波压制简况和主要的技术方法,分别对非波动方程的滤波方法和基于波动方程的多次波压制方法作了全面的论述。其次,深入研究了波动方程预测减去法的基本原理和实现过程。分别对预测减去法的两个步骤——多次波预测和自适应减法进行了详细分析。在分析传统SRME基本原理的基础上,实现了单道集SRME算法,降低了对系统硬件的要求,提高了计算速度。重点研究了近偏移距波场外推、震源子波影响消除和多次波编码中的细节问题。作为整个预测减去法中重要的一环,本文对自适应减去算法也进行了深入的剖析,对单道最小二乘算法和均衡伪多道算法进行了详细的理论推导和模型对比。建立了迭代次数、时窗长度等各种影响因素对预测减去法的直观关系,以此作为多次波压制的质量监控手段。然后,对常用的几种商业处理软件进行了总结,据此开发了专注于多次波压制的系统软件,并将其应用到理论模型和实际地震资料的处理中,取得了较好的应用效果。论文最后总结了对反馈环法多次波压制的一点认识和建议。更多还原

【Abstract】 Multiple elimination is always an important work in seismic data processing. Multiple reduces the resolution of seismic data, disturbs the recognition of primary, and damages the quality of seismic data processing seriously. So it is significant that how to elimination all kinds of multiples effectively and reserve the primary possibly in seismic exploration.The elimination of multiple based on wave equation consider not only the kinematics characteristic of wave propagation but dynamic characteristic, and also avoid some shortages when we use some filtering methods. We believe that the elimination of multiple based on wave equation will have a bright future, because it doesn’t need any priori information and have a better result.First, this thesis systemically discusses all kinds of methods about multiple elimination, including filtering methods and wave equation-based methods. Then I study the basic theory and procedures of prediction subtraction method based on wave equation. I discuss the prediction and subtraction detailedly. Based on the analysis of traditional SRME method, I achieve the single ensemble SRME method. This method reduce the request of computer’s hardware, and increase the computation speed. I study some detail issues about the extrapolation of near offset wavefield, the affection of inverse source wavelet and multiple encoding scheme. As a part of prediction subtraction method, this paper discusses adapt subtraction algorithm deeply, make detailed theoretical derivation of single channel least-square matching filter method and constrained cross-equalization expanded multichannel matching filter method, and compare these two methods with models. Establish the relation between the effectiveness of SRME and the iterative times and length of time window, which is used for quality control of multiple elimination. Then, I summarize and compare the several commercial seismic processing software, and develop a software focused on multiple elimination. I apply the software to the synthetical model and real seismic data, and get a better result. At last, I summarize some recognitions and recommendations about prediction subtraction method based on wave equation.更多还原