基于频谱分析技术预测煤与瓦斯突出带

摘要

构造煤与煤与瓦斯突出密切相关,根据构造煤地质特点构建地质模型,依据黏-弹性介质中地震波场吸收衰减理论进行模拟正演.结果表明,构造煤导致高频地震信号衰减,产生频率、振幅等异常.研究区小波傅立叶变换分频解释技术显示:无论是原生煤还是构造煤,其频谱分解技术都可使反射波频率得到拓宽,但其在不同频率上表现出明显差异,且构造煤反射波高频成分衰减强烈;另外煤层厚度的增大,将导致反射波高频成分减少,低频成分增加.通过对研究区过井连线(inline2177)8煤层的频谱分解数据体的解释,确定了构造煤发育区与原生煤(或构造煤欠发育区)范围.根据与钻孔数据的对比,认为8煤层频谱分解的扫描频率在60~70Hz时,其低频分布区域与构造煤范围高度吻合.%The tectonoclastic coal is closely related with coal and gas outburst.According to tectonoclastic coal geological features estab-lished geological model,based on viscoelastic medium seismic wave field adsorptive attenuation theory has carried out simulation for-ward.The result has shown that tectonoclastic coal can cause high frequency seismic signal attenuation and produce frequency and am-plitude anomalies.The study area wavelet Fourier transformation spectral decomposition technology has shown that whether it is primary coal or tectonoclastic coal,their spectral decomposition technology can make reflection frequency broadened, but obvious differences showing on different frequencies; tectonoclastic coal reflection wave high frequency component strongly attenuated.Besides, the in-creasing of coal thickness will cause high frequency component decreasing,low frequency component increasing.Through the interpre-tation of study area cross well line(Inline 2177)coal No.8 spectral decomposition data volume,identified tectonoclastic developed ar-ea and primary coal(or tectonoclastic coal underdeveloped)area ranges.According to comparison with borehole data,considered that when coal No.8 spectral decomposition scanning frequency is 60~70Hz,its low frequency distributed area is highly identical with tec-tonoclastic coal distributed range.