多参数岩性反演在灰岩解释中的应用

Application of Multi-parameter lithological Inversion in Limestone Interpretation

对于煤田岩性地震勘探来说,利用密度和声速测井曲线约束的波阻抗反演是主要的方法之一。由于灰岩与围岩的波阻抗差异较小,常规波阻抗反演所获得的波阻抗信息很难识别出灰岩层位。通过对姚桥煤矿西六采区灰岩多测井曲线特征的分析,发现与围岩相比,煤层的密度较低、电阻率较高;而灰岩的视电阻率特别高。因此,在灰岩解释过程中,通过对密度曲线和视电阻率曲线进行融合,获得1条拟密度曲线,同时突出了煤层密度与灰岩的视电阻率异常。利用多参数岩性反演方法获得拟波阻抗数据体,确定出灰岩的空间分布和厚度变化,为煤矿的防治水工作提供了重要依据。

The surge impedance inversion which uses the density and acoustic velocity logging curve is one of the most important methods in coalfield seismic exploration.As the surge impedance difference between limestone and surrounding rocks is small,it is difficult to identify limestone horizon with the surge impedance information acquired from the conventional surge impedance inversion.Through the analysis on the characteristics of the multi-logging curves of the western No.6 mining district in Yaoqiao Mine,it was found that the coal seam has a lower density and a higher resistivity as compared with the surrounding rock;and the apparent resistivity of limestone is very high.Therefore,a quasi-density curve was obtained by merging the density curve with the apparent resistivity curve in limestone interpretation and the anomaly of the coal seam＇s density and the limestone＇s apparent resistivity was highlighted.The quasi-surge impedance data which were obtained with multi-parameter lithological inversion method and the spatial distribution and the thickness change of limestone which were determined with this method can provide an important basis for water prevention and control in coal mines.