【摘要】 松辽盆地北部古龙断陷的地震地质条件复杂,受上覆地层对地震波反射能量的屏蔽影响,在深部火山岩等强反射界面产生了能量较强的层间多次反射波,导致古龙断陷研究区的地震资料品质较差。为消除由层间多次波引起的断陷期地层的构造假象,提高古龙断陷结构的识别精度,采用减去法进行深层层间多次波压制。方法的基本原理是:应用多次波速度对原始CMP道集进行动校正处理,然后对CMP道集进行叠加,得到多次波能量加强的单道记录,亦称为模型道,将模型道和校正后的CMP道集进行逐道匹配相减运算,再进行反动校正得到多次波压制后的CMP道集。减去法层间多次波压制方法易于编程实现,算法简单。数值算例显示,该方法可有效压制古龙断陷研究区的深层层间多次反射波,为深层地震资料的准确成像奠定了基础。更多还原

【Abstract】 Gulong fault depression is situated in the north of Songliao Basin, which is characterized by complex seismic and geologic conditions. The shielding effect of overlying formations on the seismic reflection energy generates strong interbed multiple at strong reflecting interface such as deep volcanic rock,which leads to bad quality of seismic data in Gulong fault depression.In order to remove the artifact of faulted formation caused by interbed multiple,and improve the identification accuracy of the structures in Gulong fault depression,subtraction algorithm was used for the suppression of deep interbed multiple.Firstly,NMO was carried out on original seismic CMP gather by using the velocity of multiple.Then CMP gathers were stacked to obtain the record of single trace after energy enhancement of multiple,which is also called model trace.Finally, the model trace and CMP gathers after correction were matched trace by trace to subtract each other,and inverse NMO was carried out to achieve CMP gathers.Multiple suppress based on subtraction algorithm is easily realized by programming and has easy algorithm. Numerical testing shows that the method can effectively suppress the deep interbed multiple reflection,which guarantees the accurate imaging of seismic data.更多还原