波阻抗反演在煤层底板岩性预测中的应用

Wave Impedance Inversion Application for Coal Floor Lithology Prediction

叠后波阻抗反演利用波阻抗差异区分地质体岩性,是常用的煤层顶底板岩性预测方法,在煤层安全开采以及工作面施工等方面发挥了重要作用。以实际工区为例,对反演过程中的关键技术进行了详细阐述,并基于实际地质、测井、地震资料,针对反演目的区域测井资料不足的问题,使用不同采样率的地震数据开展波阻抗反演,得到不同尺度的反演结果。结果表明在测井数量不足以及测井曲线深度未能完全覆盖目的层时,较大尺度的反演结果在分辨率上虽然存在不足,但能更好地刻画岩层结构和岩性变化,更贴近工区实际情况。

Post-stack impedance inversion uses impedance difference to distinguish geological body lithology,which is a common method for lithology prediction of coal seam roof and floor,and plays an important role in the safe mining of coal seams and construction of working faces.Taking the actual work area as an example,the key technologies in the inversion process are described in detail,based on the actual geological,logging and seismic data,aiming at the problem of insufficient logging data in the inversion target area,the seismic data with different sampling rates are used to carry out impedance inversion,and the inversion results of different scales are obtained.The results show that when the number of well logs is insufficient and depth of the logging couves does not fully cover the target layer,although the large-scale inversion results have shortcomings in resolution,they can better describe the changes of rock structure and lithology,which is more in line with the actual situation of the work area.