文档介绍：学校代码:11414
学号:S060010191
中国石油大学硕士研究生学位论文
(申请工学硕士学位)
衰减介质中纵波和转换波的正演模拟及补偿
学科专业:地球探测与信息技术
培养方向:地球物理探测方法与技术
硕士生:严红勇
指导老师:刘洋(教授)
入学日期:2006年9月论文完成日期:2009年4月
摘要
纵波和转换波联合的多波地震勘探技术是解决复杂油气勘探的有效技术,提高转换波的分辨率是其关键问题之一。而纵波和转换波在地层介质的传播过程中,由于地层吸收、散射等各种原因,波的能量通常会衰减,相位产生畸变,严重影响了纵波和转换波的分辨率,而且转换横波受此影响更严重。研究地震波在衰减介质中的传播特征,有效地计算地层介质的Q值、消除地层吸收对纵波和转换波传播的影响,是提高纵波和转换波分辨率的关键。本文分别利用波场外推法和任意偶数阶有限差分模拟衰减介质中的地震波传播,模拟结果精度高、与理论分析相一致。通过模拟实例发现,地层的粘滞性使地震波的能量衰减,分辨率降低。模拟结果可以用来进行提高分辨率的地震处理方法研究。本文提出了从叠前纵波和转换波道集中估算横波Q值的方法,并利用沿射线路径的波场延拓,将一种稳定有效的反Q滤波方法应用到叠前共炮点纵波和转换波道集的衰减补偿中。模型资料结果表明,本文提出的估算转换横波Q值的方法精度较高;模型资料和实际资料的吸收补偿结果表明,此稳定全反Q滤波能有效地提高叠前纵波和转换波资料的分辨率。
关键词: 纵波转换波衰减 Q值反Q滤波
Forward modeling pensation of PP- and PS-waves in attenuated media
ABSTRACT
PP- and converted PS-bined multi-wave seismic exploration technology is effective to solve the exploration problems plicated area. The improvement of converted wave resolution is one of the key problems. Nevertheless, the energy of wave could be attenuated and the phase could be distorted by the reason of absorption and scattering in the strata or other factors during the propagation of P- and converted PS-waves in the strata, which severely affects the resolution of PP- and converted PS-waves, the converted PS-waves are affected more. To research the propagation characteristic of seismic wave in the attenuated medium, and pute Q value of strata, and eliminate the effect to the propagation of PP- and converted PS-waves, which are the crucial to improve the resolution of PP- and converted PS-waves. This thesis takes the advantage of wave field extrapolation method and the simulation of seismic propagation in attenuated media based on arbitrary even order finite difference method separately. The result of simulation has a high precision, which consists with theoretical analysis. According to the example of simulation, we find that the viscosity of strata causes the attenuation of energy and the declination of resolution. In addition, the result of simulat