煤田陷落柱特殊波对陷落柱解释的影响

AN ANALYSIS OF THE SPECIAL WAVE IMPACT ON THE INTERPRETATION OF THE COALFIELD COLLAPSE COLUMN

对典型陷落柱建立圆锥状陷落柱数学模型,采用波动方程法对陷落柱模型进行地震射线追踪和波场模拟。模拟结果说明:由于陷落柱构造形态的特殊性,在陷落柱附近形成了正常煤层反射波、断陷点绕射波、延迟绕射波、延迟反射波及柱顶绕射波组成的纵波波场。在此基础上,模拟野外放炮,然后对生成的单炮记录进行常规处理,形成叠加、偏移剖面。通过对正演剖面和实际揭露资料分析,认为陷落柱特殊波的存在,是判别陷落柱构造的一个重要特征,但又造成了实际揭露陷落柱规模往往小于地震资料解释结果。将研究结果用于实际勘查,效果较好。

In the light of typical cone-shaped columns in the Lu＇an mine of Shanxi Province,the authors established a mathematical model for the collapse column,and used the wave equation model for seismic ray tracing and wave-field simulation of collapse columns.The simulation results show that,due to the special nature of the collapse columns,such waves as the normal reflected wave,the fault-point diffraction wave,the delay diffraction wave,the delay reflected wave and the ＂diffraction wave＂ consisting of P-wave field are formed around the collapse columns.On such a basis,the field shot was simulated,and then a single shot record for routine processing was generated to produce stacking sections and migrated sections.The forward section and the actual data analysis reveal that the fallen columns of the special wave constitute an important feature for recognizing collapse columns;nevertheless,the resultant scale of the actual seismic data interpretation is often smaller than the scale of actual collapse column.Some suggestions are also put forward for reference.