利用三维地震资料研究鱼卡煤田7煤层厚度

3D Seismic Data Determination of No.7 Coal Seam Thickness in Iqe Coalfield

7煤层为青海省鱼卡煤田主要可采煤层,中国煤炭地质总局水文物测队利用该区的高精度三维地震数据体,结合钻孔资料,对7煤层厚度与其反射波T7波的相位特征、振幅特征、频率特征进行相关性研究。结果表明,T7波的相位特征与7煤层厚度有较好的相关性,而T7波的频率特征、顺层振幅与7煤层厚度的相关性很差,即使煤层较厚时也是如此。通过例举薄煤层、较厚煤层、厚煤层等具体实例,说明煤层与反射波相位个数及相位时差具有正相关关系。由不同煤厚模型(0～50m)正演出的自激自收时间剖面反射波相位特征,也验证了7煤层厚度变化与其T7波相位特征的关系。

The No.7 coal seam is the main mineable coal seam in the Iqe coalfield. Our team used the area＇s high precision 3D seismic data volumes combined with drilling data carried out correlativity study between No.7 coal thicknesses and its T7 reflection wave phase, amplitude and frequency characteristics. The results have demonstrated that the phase characteristics of No.7 coal thicknesses have better correlativity, while frequency characteristics and bedding amplitude of T7 wave have poor correlativity with No.7 coal thicknesses, even if when coal seam is rather thick. Through practical examples of thin, thicker and thick coal seams, demonstrated that there are positive correlations exist between coal seam thicknesses and reflection wave phase number and phase moveouts. From different coal thickness （0-50m） models forwarded self shot and receiving time section reflection wave phase characteristics and validated relation between No.7 coal thickness changing and T7 wave phase characteristics.