基于Wyllie平均方程的煤系岩溶陷落带富水性预测

The water-abundance prediction of karst collapse zone based on Wyllie time average equation

在岩溶陷落带孔隙发育,原来坚硬致密的岩石改变了性质,造成岩石密度、波速、电阻率等物性参数发生变化,这些物性异常引起地震波波场改变,从而导致地震波特征参数如时间、反射系数、波阻抗等的变化。利用Wyllie时间平均方程可以建立充水岩体的地震波速度和孔隙度之间的关系。根据密度平均方程建立充水岩体密度和孔隙度之间的关系,进而建立波阻抗和孔隙度之间的关系。因为岩溶陷落带孔隙发育情况和导通性决定了其是否能成为导水通道,利用波阻抗属性可预测岩溶陷落带孔隙度发育情况,这可为判断富水性提供重要参考依据。

In the karst collapse zone of coal measures, the physical parameters of original hard and compact rock such as density, velocity, resistivity and so on change because of pore development. These physical abnormities cause the change of seismic wave field, inducing the change of the characteristic parameters of seismic wave such as velocity, reflection coefficient and impedance. The relation between velocity or density and porosity can be built based on Wyllie time average equation and density average equation, and then the relation between impedance and porosity can be built. The transmissibility of karst collapse zone depends on the pore development and continuity, therefore the porosity development in karst collapse zone in coal measures can be predicted using impedance at-tributes, providing foundation for judgment of water abundance.