【作者】 李玮；

【导师】 张志禹；

【作者基本信息】 西安理工大学 ， 通信与信息系统， 2008， 硕士

【摘要】 剩余静校正是陆地地震资料常规处理流程中重要的一环,剩余静校正问题解决的好坏,直接影响到地震勘探的效果和精度,已经成为制约地震勘探的关键性问题。以往基于反射波的剩余静校正技术,通常是在反射波CMP叠加剖面上选择波组连续性好、信噪比高的反射层作为参考层制作模型道,然后利用互相关的方法求取炮点和接收点的剩余静校正量。而当反射波的信噪比过低时,常规的剩余静校正方法由于不能建立准确的模型道而失效。此外,现有的大多数静校正方法都要利用初至时间的信息,初至波拾取的精度和速度就成为了衡量静校正效果好坏的关键因素。对于复杂地区的低信噪比数据资料,采用拾取初至时间信息进行处理的效果并不是很理想,给后续的静校正量计算带来误差。本文针对目前西部油气勘探中迫切需要解决的复杂地表区静校正技术难题,对初至折射波解决二维和三维静校正问题进行了研究,提出了一种基于差分法的初至折射波自动剩余静校正方法。该方法不需要拾取初至时间,它利用折射波信噪比高的特点,运用折射波传播原理,首先对地震数据进行线性时差动校正,在共炮点道集上用互相关方法计算各个相邻道之间的时差;然后结合二维和三维观测系统各自的特点,对于炮点和检波点分别建立关于各自相邻点之间的剩余静校正量时差的差分方程;最后,对于二维数据采用递归求和方法求解差分方程,对于三维数据采用高斯-塞德尔迭代法求解差分方程组,分别得到每个炮点和检波点的剩余静校正量。通过将此方法应用于模型数据和实际数据的处理,结果表明,本文提出的折射波剩余静校正方法对于解决高频剩余静校正量问题具有很好的实用性和可行性。更多还原

【Abstract】 Residual static corrections play an important role in general seismic data processing flow. And that it is resolved well or not directly determine the effect and accuracy of the seismic exploration. So it has become a key problem that constricts seismic exploration.Nowadays the techniques of reflection waves based residual static corrections always choose well-continual and high S/N ratio reflection layer as reference layer and make piloted trace on CMP stacked section. Then the residual static corrections of source and receiver are calculated by using cross-correlation. But when the S/N ratio of reflection wave is low on stacked section, the reflection residual static corrections are invalid because we can’t build a right piloted trace.. Base on this instance, we put forward the residual static corrections technique by using refraction first breaks. Otherwise, the most techniques of residual static corrections are based on first-break pick up time. The effect and accuracy of the first-break picking up become an important thing for the processing well or not to the residual static corrections. The technique of first-break picking up is not work well for the low S/N ratio data of the complex areas, and bring a few error for the the statics caculating.To solve serious static corrections problems in complex near-surface areas of western China, different refraction first-break statics methods are studied in this thesis. The paper presented a new method of refraction first-break automatically residual-static correction in the face of the problems that the residual-static corrections techniques have today. The method doesn’t need first-break times of refraction waves. Firstly, it carries out the LMO (linear moveout) to the seismic data, and then calculate the time difference of each adjacent trace by using cross-correlation method in the common shot gathers. Secondly, the linear equations are constructed according to the different feature of 2D and 3D surveillance system. Finally, the residual statics have been obtained by using recursion and sum method to solve 2D equations and Gauss-Seidel iterative to solve 3D equations. Theoretical modeling and practical data processing show that the residual static corrections by using refraction first-break waves given in this paper is practical and feasible to the high frequency residual statics.更多还原