【摘要】 为选取最佳炮孔耦合介质以改善碳酸盐岩中地震勘探震源的激发效果,基于弹性波理论建立炮孔不同耦合介质(空气、水、黏土)孔壁爆炸载荷及透射波比能的计算方法,借助Matlab编程计算得到解析解,并绘制图形进行对比分析。在典型碳酸盐岩场地进行炮孔不同耦合介质的地震波激发试验,应用基于功率谱的能量分析方法对试验数据进行分析。理论计算和现场试验研究均表明:水不耦合装药时,采集的地震波信号能量最强,信号频率最高、信噪比最低;空气不耦合装药时,采集的地震波信号能量次之,信号频率最低、信噪比最高。因此,实际碳酸盐岩储层中,应采用空气不耦合装药的结构形式,并加大炮孔装药量以弥补地震波信号能量,从而改善地震勘探激发效果。更多还原

【Abstract】 To choose the best borehole coupling medium and improve the seismic exploration excitation effect,the calculation methods of explosion load and transmitted wave specific energy based on the theory of elastic wave are built.The analytical solutions are calculated by program in Matlab;and the graphics are drawn for the comparative analysis.Then,the field experiment is conducted in typical carbonate rock site;and the experimental data are analyzed by the way of energy analysis based on the power spectrum.The theoretical calculation and experimental results show that:(1) When the coupling medium of decoupling charge is water,the seismic wave energy is the biggest,the frequency is the highest,and the signal-to-noise ratio is the lowest.(2) When the coupling medium of decoupling charge is air,the seismic wave energy is smaller than that of water,the frequency is the lowest,and the signal-to-noise ratio is the highest.So,in order to gain a good seismic excitation effect,the air should be used as the coupling medium of decoupling charge in seismic exploration,and the seismic wave energy can be made up by increasing the total charge.更多还原