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石油勘探所发展的地震勘探技术为煤田勘探提供了一套有效的方法。由于目的是探测1500米范围以内的小断层而不是更深部的构造特征,因此,新的技术要求在传统地震剖面图的最初部分具有更高的分辨率。即要通过扩展频谱的高频端来获取宽的频带宽度。达到这一目的的途径是:①将炸药量按比例减少和采用单个检波器代替组合检波器;②减小空间的和时间的采样间隔。不按比例缩小的噪声包括静态误差和地滚波。考虑到静态误差、地滚波及近地表层的高切滤波效应,迫使我们在有可能的地区采用深部爆炸井和深部检波器。这种方法已由试验证实,并在一条正规的生产基线上使用了这种方法。已经证明,该方法能够清晰地分辨深度在800米,垂直落差约5米的断层。
Seismic exploration techniques developed by the Petroleum Exploration Institute provide an effective method for coalfield exploration. As the aim is to detect small faults within a range of 1,500 meters rather than deeper structural features, the new technique requires higher resolution at the very beginning of conventional seismic profiles. That is to be wideband by expanding the high-frequency side of the spectrum. The way to achieve this is to: (1) reduce the amount of explosives in proportion and use a single geophone instead of a combination geophone; (2) reduce the spatial and temporal sampling intervals. Unscaled noise includes static errors and ground roll. Taking into account static errors, the high-shear filtering effect of ground roll and near-surface layer forces us to employ deep exploding wells and deep geophones wherever possible. This method has been experimentally confirmed and used on a regular production baseline. It has been proved that this method can clearly distinguish faults with a depth of 800 meters and a vertical drop of about 5 meters.