CH盆地煤田高分辨率地震勘探

在煤田高分辨率地震勘探中,首要的问题是针对研究的对象设计合理的采集参数,在资料处理过程中要尽量保持已采集到的高频有效信息。在CH盆地的煤田地震勘探中,采样间隔选为1ms,最大炮检距为235m,道距为10m,接收频宽为16-250Hz。在资料处理中,针对不同的t₀时间,分别实施高通、带通和时变滤波;反褶积因子长为60、70个样,白噪因子为10～15%;注重精细速度分析、真振幅恢复和偏移技术的应用。利用瞬时信息、层速度、反射系数和亮点显示,能够近似地识别出煤层的空间位置。此外,利用高分辨率地震剖面还可识别出错动半个相位的断层,并清楚地显示地层不整合接触关系和古河道的形态。

High resolution seismic prospecting for coal in CH basin

Two key points in high resolution seismic prospecting for coal are (1)to design reasonable acquisition parameters for exploration target, and (2)to preserve useful high frequency components as many aspossible during data processing. In the coal seismic exploration inCH basin, we used the following reasonable acquisition parameters;Ims sampling interval, 235m maximum offset, 10m group interval and 16-250 Hz frequency band, In seismic data processing, high-pass fiite-ring，band-pass filtering and time-variant filtering are respectively usedaccordiwg to different normal reflection times(t times); the length of deconvolutfon operator ranges from 60 or 70 samples; white noise accounts for 10-15‰，and particularly, refined velocity analysis, trueamplitude recovery and migration technique are applied to data pra-cessing, Coal seam can be appreximately located using instantaneous information, interval velocity, reflection coefficient and bright spot.Furthermore, the minor fault whose throw is only half phase, unconfortuity and palaeochannel can be clearly shown on the high resolution seismic section,