海上宽方位地震资料多次波压制技术研究及应用

Research and Application of Multiple Suppression Techniques for Marine Wide-azimuth Data

宽方位采集在有效解决复杂构造成像和储层预测难题的同时,也在一定程度上增加了多次波压制的难度。多次波传播路径不再满足平行测线的二维平面假设,导致常规二维方法压制效果不理想。本文根据海上地震资料电缆鬼波、水层相关多次波、长周期多次波在宽方位观测系统中的特点,分别采用了基于τ—p域水陆检标定的电缆鬼波压制方法、全三维平面波域多次波压制方法和基于椭圆约束的三维Radon域滤波方法。实际资料应用效果表明,上述三种方法较常规方法有明显的优势,可以更好地适应宽方位采集特点。在有效压制多次波的同时,较好地保留了宽方位采集所携带的振幅和速度等信息,为后续构造成像和储层预测提供良好的数据基础。

Wide-azimuth acquisition not only effectively solves the problems of complex structure imaging and reservoir prediction,but also increases the difficulty of multiple suppression to a certain extent.The propagation path of multiple waves no longer satisfies the two-dimensional plane assumption of parallel lines,resulting in inaccurate multiple model predicted by 2D method.In this paper,we first analyze the characteristics of cable ghost,water-layer-related multiple and long period multiple in wide azimuth observation system.Then we suppress the cable ghost after dual-sensor calibration in theτ-p domain,the water-layer-related multiple in the full 3D plane wave domain,and the long period multiple by means of 3D Radon domain filtering based on elliptic constraint.The field data tests show that these methods have obvious advantages over conventional ones,and can better adapt to the characteristics of wide-azimuth acquisition.While well suppressing multiple waves,the amplitude and velocity information carried by wide-azimuth acquisition is retained,which provides a good data base for further imaging and reservoir prediction.