地震勘探在地层倾角较大地区的应用初探

在地层倾角较大地区，尤其是通过钻孔见煤深度推断的地层倾角变化较大地区，钻孔之间的地层及构造变化情况，若仅依靠钻孔资料，可能会得出与事实相反的结论。大倾角地层地区的地震勘探，须解决的地质问题主要有：受构造运动影响，煤系地层被风化剥蚀后，与新生界呈不不整合接触关系的煤层露头点：背斜轴部发育的褶曲、断层以及煤层赋存形态的变化；受大断层的牵引作用，其附近地层倾角变化及小断层的发育情况。在地震资料处理时，对干涉波应采用炮炮计算切除量及去线性干扰模块进行切除：并认为偏移处理中的层速度，做沿层平滑较均方根速度平滑更加合理。在进行解释时，应注意分辨不同的波形特征及断点识别标志。实例表明：地震勘探可以准确地控制单斜地层因断层导致的背斜构造及地层倾角变化情况。

An Initial Discussion on Application of Seismic Prospecting in Larger Strata Dipping Area

In larger strata dipping area, especially in such area is only deduced by coal seam depth changing in boreholes, if only rely on drilling data, may be caused an opposite conclusion. The seismic prospecting in larger strata dipping area, have to be solved geological problems have： affected by tectonic movement, coal measures strata after eroded by weathering, concealed coal seam outcrops unconformable contact with Cenozoic strata; folds, faults developed on anticline axial region and changing of coal seam hosting configuration; major fault traction strata dip angle changing and minor faults development. During the seismic data processing, the disturbing wave muting amount should be estimated shot by shot and muting by linear interference moved module; to interval velocity in migration processing, it is more reasonable to use layer smoothing than root-mean-square velocity smoothing. During interpretation, should pay attention to distinguish different waveform characteristics and fault point identification marks. Examples have demonstrated： seismic prospecting can control fault caused anticline and dip angle changing strata in monocline strata accurately.