起伏地表条件下的混叠数据最小二乘逆时偏移

Multisource least-squares reverse time migration for irregular surface

剧烈起伏地表给地震成像带来巨大挑战.提出了一种曲网格-矩形网格耦合机制,并将耦合网格机制应用到最小二乘逆时偏移中,推导了辅助坐标系下的梯度公式、偏移算子和反偏移算子,提出了起伏地表最小二乘逆时偏移方法,在起伏地表复杂构造的成像中起到了很好的效果.对于混叠数据,采用最小二乘逆时偏移技术可以压制成像过程中的部分串扰噪声,同时引入静态编码技术可以进一步压制串扰成像噪声,最后通过整形规则化滤波技术可以很好地消除串扰成像噪声.

Dramatic topographic surface brings great challenges to seismic imaging.A curvilinear-rectangular coupled grid scheme is proposed and applied to Least-Squares Reverse Time Migration(LSRTM)to propose an irregular topographic LSRTM method by deriving a gradient formula,migration operator and de-migration operator in an auxiliary coordinate system,which achieves good results in imaging for complex structures with irregular surface topography.For multisource data,LSRTM can suppress some crosstalk noise of the image.Static encoding technology can be introduced to further suppress the crosstalk imaging noise.Finally,the shaping regularization filtering is introduced to well eliminate the crosstalk imaging noise.