矿井地震反射波观测系统优化正演模拟研究

Research on Optimization Forward Modeling of Mine Seismic Reflection Wave Observation System

为了加强断层构造超前探测的精确性,针对巷道前方存在的落差大于1/2煤厚的中小型断层的影响,利用Tesseral地震正演软件建立井下不同倾角断层的地质模型,基于矿井反射波方法原理,进行地震波场模拟,对比地震记录、波场快照及偏移成像,分析断层面的反射波特征和成像效果,优化地震反射波观测系统参数,为矿井煤巷工作面回采提供技术指导。研究表明:倾角处于10°~45°的低倾角断层,随着倾角的逐渐增大,成像点与震源点的距离逐渐增大,成像效果逐渐优化,观测系统总长度需在50~100 m内逐渐减小。倾角处于45°~90°的高倾角断层,随着倾角的逐渐增大,成像点与迎头位置的距离逐渐减小,成像效果较好且无明显差异,观测系统总长度需在30~50 m内逐渐减小。

In order to enhance the accuracy of the advance detection of fault structures,in view of the influence of small and medium-sized faults with a drop greater than 1/2 coal thickness in front of the roadway,the Tesseral seismic forward modeling software is used to establish underground geological models of faults with different dip angles,based on the principle of the mine reflection wave method,carry out seismic wave field simulation,compare seismic records,wave field snapshots and migration imaging,analyze the characteristics and imaging effects of the reflected waves of the fault plane,optimize the parameters of the seismic reflection wave observation system,and provide technical guidance for the mining of coal roadways.Results suggest that for low-dip faults with an inclination angle of 10°to 45°,as the inclination angle gradually increases,imaging the distance between the focal point and the focal point gradually increases,and the imaging effect is gradually optimized.The total length of the observation system needs to be gradually reduced within the range of 50 to 100 m.For high-dip faults with an inclination angle of 45°to 90°,as the inclination angle gradually increases,the distance between the imaging point and the head-on position is gradually reduced,and the imaging effect is better without obvious difference.The total length of the observation system needs to be gradually reduced within the range of 30 to 50 m.