煤层岩浆岩侵入区的交会图定量预测技术——以卧龙湖煤矿为例

Quantitative predicting of coalbed igneous intrusion by crossplot analysis:a case study from Wolonghu Coal Mine

以卧龙湖煤矿某采区实际钻孔资料为基础,建立了8个符合采区实际情况的煤层模型。通过合成地震记录方法,获得了所有模型的正演合成地震记录。并通过地震属性技术,提取了上述模型10号煤层反射波的波峰振幅、波谷振幅、瞬时振幅、瞬时频率和甜面体值等属性。在此基础上,利用交会图技术分析了正常煤层和不同岩浆岩侵入煤层在属性交会图分布上的对应位置;并且利用蒙特卡罗模拟法模拟了更接近真实情况的属性交会图。通过分析蒙特卡罗模拟后的属性交会图,确定了属性交会图预测岩浆岩侵入区的定量划分标准。将此标准应用到实际采区,所划分的正常煤与变焦区、变焦区与岩浆岩完全替代区边界与钻孔数据和井下采掘数据一致,平面摆动误差较小。

8 models corresponding to different coalbed structure were built on the actual drilling data of a mining area from Wolonghu Coal Mine.By using the method of synthetic seismogram,all synthetic seismograms of above models were achieved.And by using the technique of seismic attribute,the attributes of peak amplitude,trough amplitude,instantaneous amplitude,instantaneous frequency and sweetness were extracted from No.10 coal reflections of above models.On this basis,the technique of crossplot analysis was used to study the distribution pattern of attribute crossplot points of normal coalbed and magmatic intrusion zone.Then the Monte Carlo simulation was used to simulate new attribute crossplots which closer to actual conditions.After analyzed the simulated attribute crossplots,a quantitative standard of interpreting normal coalbed and magmatic intrusion area was given.After applied this standard on actual data of mining area,the predicted boundaries between normal coalbed and coked area and between coked zone and magmatic intrusion area are fully complied with the validation of drilling and underground mining,and the smallest horizontal error is less than 10 m.