The Preliminary Study Andapplication Of Reflection Seismic Exploration Technique Applied In Coal Mine Underground

At present, the surface seismic exploration technology has developed and matured which had been widely used in the oil and gas exploration, coal resources exploration, engineering disease detection and other fields. However, the surface seismic exploration technology has its limitation when to solve the complex underground geological problems, which forcing people to turn our attention to the research of seismic exploration technique applied in coal mine underground.In this paper, the author summarized an overview on research situation of seismic exploration technique applied in coal mine, which based on access to the domestic and international relative literature data of seismic exploration technique applied in coal mine in nearly 20 years. And the existent difficult problems is analyzed in seismic exploration technique applied in coal mine underground, Such as weakness in basic research, low S/N compared to surface seismic exploration, lack of coal mine explosion-proof equipment applied in coal mine underground and the few people engaged in the seismic exploration underground, etc. The author developed a brief advantage and disadvantage among the finite difference method, finite element method, pseudo spectral method, spectral element, integral equation method and ray-tracing method and compared the application effects of different forward modeling software.In this paper, the author simulated the elastic wave field inside the mine tunnel by using FORWARD simulation software, obtain the following understanding: stimulate in the roadway, the reverberation caused by tunnel top and bottom interface affected the reflection of coal seam below the tunnel seriously, the receivers on the top of roadway receive sound waves and some converted waves, the receivers on the bottom of roadway receive X, Z components seismic wave field is complex, but Y-component is relatively simple. Then according to the conclusions of numerical simulation of seismic wave field, carry out seismic physical simulation inside the coal mine tunnel. After analyzing the actual seismic data, it is found that the receivers on top of tunnel receive sound waves propagating through the air, its energy is very small compared to other locations, but has high dominant frequency. Energy concentrated in the bottom, the roof and lateral wall receive very small energy. According to the seismic forward simulation and physical simulation, the practical application of 2-D seismic was carried out inside coal mine tunnel. This application achieved good results in detection of the under-coal seam, which is verified by actual drilling technology. This case study shows that this technology has the ability to detect underground and has a higher resolution, and also has a great development potential. Finally, the feasibility of 3-D seismic applied in coal mine underground is analyzed and a preliminary experiment had been carried out.