Experimental Research On Methods Of Mine Seismic While Drilling

Method of seismic while drilling is a new type of seismic exploration method, It use the vibration between bit and formation as the source. It could be divided to vibration logging while drilling, the bit while drilling seismic and VSP with drilling in broad sense. In this paper, the logging while drilling vibration were studied with extensive experiments, and the bit while drilling earthquake theory is discussed.Firstly, The mechanical properties of the rock are introduced, especially the properties closely with drill role, such as Elasticity, strength, plasticity and hardness. Impact of drilling, cutting mechanism and the rock movement and force analysis are discussed.Two typical rock bit and PDC bit are analysised collectively. This paper expounds the three basic form of drill string vibration, the longitudinal vibration \ torsional vibration and the transverse vibration, and the motion law and calculating natural frequency are analyzed.In terms of the drilling and seismic signal processing method, Short-time Fourier transform and correlation analysis are emphatically studied and practical application steps are put forward. Fast Fourier transform to real-time calculation with drilling and seismic signal spectrum bysliding window on time domain vibration signal, getting to corresponding of the signal time and frequency. The characteristics of time domain waveform of the seismic signal with drilling can be extracted through the autocorrelation algorithm. Direct wave and reflected wave signal can be extracted from drill string reference signal through the cross-correlation algorithm. Plastic processing was used to the bottom reflection wave signal since the nature of ductility.Seismic acquisition instrument and application software with drilling was developed, and the experimental study was carried Indoor experimental field and mine roadway. Explain hierarchical decision of different lithology through the experimental data analysis results, and the effective ingredients was extracted from the noise interference in the frequency domain. Rig vibration and lithology identification band distribution range was determined.The coal seam drilling experiment, coal gangue can be identified, and the roof and floor.The paper provides details to attention of drilling and seismic method.