【摘要】 柴达木盆地三湖地区地震资料受广泛发育的气云的影响,导致纵波在含气构造部位成像质量较差,而转换波勘探技术可望成为解决气云区成像问题的有效手段。本文以柴达木盆地涩北气田为实例,采用伪谱法对该区气云进行数值正演模拟;通过对模型数据的分析研究,可见到明显的二极化现象,该现象是影响转换波成像质量的重要因素;应用将转换波速度分解为基本速度和速度扰动的二极化校正方法,可消除转换波二极化效应的影响,提高转换波成像质量。采用上述方法对该区二维三分量地震数据进行处理,可在转换波数据上观测到明显的二极化现象,二极化校正方法的应用的确能提高气云区转换波成像质量。更多还原

【Abstract】 Gas cloud is widely distributed in Sanhu area,Qaidam Basin.Converted-waves(C-waves) are effective to imaging through it which degrades P wave imaging.In this paper,we model a gas cloud within the Sebei Field using the pseudo-spectral method to study the diodic effect.When the model data is processed and analyzed,we can find the significant diodic effects.It may be compensated by using a velocity perturbation method which decouples the diodic moveout into two parts: the base velocity and the velocity perturbation.The converted wave imaging is improved by the application of diodic moveout.The same work flow is applied to the real 3C-2D data from Sebei Field.We obtain almost the same result as on the synthetic data.更多还原