【作者】 丁仁伟；

【导师】 仝兆岐； 李振春；

【作者基本信息】 中国石油大学 ， 地质资源与地质工程， 2009， 博士

【摘要】 随着油气勘探开发的进一步深入,对岩性解释需求迫切。为了能够高效率的为解释工作提供可靠的保幅剖面,开展了双聚型CFP保幅处理及并行实现的研究工作。在研究了传统的基于射线理论的双聚型CFP保幅处理后,提出了基于波动方程波场延拓理论的双聚型CFP保幅处理方法;针对CFP技术计算效率较低的问题,研究并实现了以上方法的并行计算,研发了CFP技术处理系统以方便该地震成像方法的推广应用。在基于射线理论的双聚型CFP保幅处理的研究中,第一步聚焦利用有限差分走时计算,等时原理、差异时移分析等方法技术,研究计算聚焦算子、生成CFP道集、确定共聚焦点响应位置和估算正确的聚焦算子。将旅行时和振幅信息结合在一起,使算子的振幅符合了波场传播特征;采用基于稳相原理和菲涅尔带叠加的方法,提高了CFP道集的分辨率和信噪比。在第二步聚焦中,利用褶积和相关原理,生成网格点道集。借助Radon变换,求取反射系数函数,实现了射线理论保幅处理及其AVP分析。在基于波动方程波场延拓理论的双聚型CFP保幅处理的研究中,分别在两步聚焦过程中采用波场延拓技术,实现了半波动和全波动的处理流程。通过考虑波前扩散、地质条件的影响,设计了消除采集效应和传播效应的保幅算子。通过改进傅立叶有限差分的延拓算子,补偿了几何扩散损失引起的振幅误差。在以上两种处理过程中,通过分析DTS面板,更新算子,逐步更新速度场,解决了初始速度模型不准确的问题,保证了所求取的成像结果的正确性。模型试算和实际数据试处理以及CFP-AVP分析结果都表明了基于射线理论和基于波动方程波场延拓理论的双聚型CFP保幅处理方法的有效性和实用性。在CFP保幅处理技术中,计算效率问题是阻碍其推广应用的一大瓶颈,根据并行计算的实现原理,利用消息传递机制,设计实现了数据并行和基于检查点的主从式并行的两种并行算法,并分别将其应用到双聚型CFP保幅处理上,提高了计算效率。基于Linux操作系统,结合跨平台的C++图形用户界面库Qt,使用C/C++和Fortran编程语言混合编程、多线程和面向对象等技术,研发了CFP保幅处理系统。该系统的实现也为地震资料处理软件的研发提供了一套解决方案。利用该软件对理论模型数据和实际地震资料进行了试算,获得了比较理想的结果。更多还原

【Abstract】 With the development of gas and oil exploration and exploitation, lithologic interpretations are in the great need. In order to efficiently provide interpretations more precise amplitude-reserved section, we studied amplitude-preserved processing based on bifocal version of CFP technology and its parallelization. After the study of amplitude-preserved processing based on bifocal version of CFP technology using conventional ray theory, we pointed out amplitude-reserved processing based on bifocal version of CFP technology using wave equation wave field extrapolation theory. Parallelization of those two methods is presented in this paper for promoting the computation efficiency. We also developed a GUI for the wide use of these methods.During the study of amplitude-preserved processing based on bifocal version of CFP technology using ray theory, in the first focusing step, by using the method of the finite difference to compute the travaltime, using the principle of equal time and the analysis of differential time shift, we studied the computation of the reversed-time focusing operator, the computation of synthetic CFP gather, the position identification of CFP response and the evaluation of correct focus operator. We combined traveltime and amplitude together to make the amplitude of operator meet the feature of wave field propagation. We used the principle of stationary phase and the stack of Fresnel band to promote the resolution and signal noise ratio of CFP gather. In the second focusing step, using the principle of convolution and correlation, grid point gathers are generated. We got reflection coefficient functions by using the Radon transformation. Ultimately we realized amplitude-preserved migration and the analysis of CFP-AVP based on ray theory.During the study of amplitude-preserved processing based on bifocal version of CFP technology using wave equation wave field extrapolation, we realized a half wave equation and full wave equation processing flow. We fully considered the influences of wave front diffusion, geological condition, designed the amplitude-preserved operator which can eliminate the effect of receivers and propagation. We improved FFD extrapolation operator to compensate the amplitude difference generated by geometry diffusion loss. In those two processing, we used DTS panel analysis to update the operator and the velocity field, which we can get the correct velocity model and garentee the correct imaging result. Tests using model data and field data, and CFP-AVP analysis all proved the validity and practicality of amplitude-preserved processing method based on bifocal version of CFP technology.The computational efficiency of amplitude-preserved processing based on bifocal version of CFP technology is a big problem which can prevent the imaging method from widely use to the industry. According to the principle of parallelization, and using MPI scheme, we designed and realized two parallel algorithms. One is data parallel algorithm, the other is master-slave parallel algorithm based on check points. We improved the computational efficiency by applying them to amplitude-reserved processing based on bifocal version of CFP technology.A seismic data processing system based on CFP technology has been developed based on Linux operating system, combining a cross-platform C++ graphical user interface library Qt, using mixed programming languages including C/C++ and FORTRAN, the multi-tread technology, OOP (Object-Oriented Programming) thinking, etc. This will also provide a solution for the development of other seismic data processing software. We tested it using model data and field data, and get good results.更多还原