线性时差校正技术在噪音压制中的应用

对于一个横向、纵向偏移距比较大的三维地震数据而言，折射波等噪音的线性形态会随着横向偏移距的加大而向着双曲线形态变化。当炮点位于某检波点线附近，横向偏移距较小的情况下，该检波线接收到的线性噪音在地震记录上呈线性状态分布;当炮点远离排列，横向偏移距比较大时，该排列单炮上的线性噪音则呈双曲线形态，并且随着横向偏移距的加大双曲现象就越明显。常规FK滤波等压制线性噪音的方法，对于这种由于横向偏移距增大而引起的非线性噪音其压制能力较差。笔者采用线性时差校正的方法，首先将横向偏移距对线性噪音旅行时的影响消除掉，恢复其线性形态，再应用线性噪音压制技术将其压制掉，最后进行反线性时差校正，以达到高精度噪音压制的目的。目前这种方法在宽方位角采集的数据上取得比较好的效果。 

Application of Linear Time Difference Correction in Noise Attenuation

When the xline and inline offset ratio in the 3-D seismic data is big,the linear waveform of reflection noise changes toward the hyperbola waveform with xline offset increase.When the source location is near the geophone line and the xline offset is small,the noise waveform accepted by the geophone line in the seismic record is linear;in contrast that the source location is far away the geophone line and the xline offset is large,the noise waveform in the seismic record is hyperbolic.The linear noise attenuation technology,such as FK filter,has no ability to attenuate hyperbolic shape noise.In this paper,we apply the linear time difference correction to eliminate the affections of the xline offset on the linear noise travel time,and to recovery the linear waveform which is affected by shot gather and big xline offset,then use the linear noise attenuation technology to attenuate the linear noise,and finally do the inverse linear time difference correction to recover normal offsets of the shot records.This technology has been successfully used to the wide-azimuth collected data.