联合反演在煤层顶底板岩性预测中的应用

为了提高煤层顶底板岩性预测的精度,首先进行了含煤地层波阻抗反演,利用煤层在波阻抗体上表现为异常低值、灰岩在波阻抗体上表现为异常高值的特点区分了煤层和灰岩;针对剩余的砂泥岩混合岩性体,由于自然伽马曲线对砂岩和泥岩极其敏感,因此采用自然伽马拟声波反演的方法得到了自然伽马体,从而有效地区分了砂岩和泥岩,实现了煤层顶底板岩性的精确预测。因此,采用波阻抗反演和拟声波反演联合的方法能够有效预测煤层顶底板岩性。

Joint inversion in the application of coal seam roof and floor lithologic prediction

In order to improve the accuracy of lithologic prediction for coal seam roof and floor,impedance inversion was firstly conducted to distinguish the coal and limestone because coal has a characteristic of abnormally low value for impedance and limestone has an abnormally high value.For the rest of mixed sand mudstone lithologic body,due to the natural gamma curve is extremely sensitive to sandstone and mudstone,natural gamma pseudo acoustic inversion method was used to obtain the natural gamma data volume so the sand and shale can be identified easily,therefore the accurate forecast of lithologic prediction for coal seam roof and floor is realized.As a result,by combining the methods of impedance inversion and pseudo acoustic inversion,the lithology prediction of coal roof and floor can be effectively predicted.