【摘要】 为逼近油井实际情况,本文处理圆柱状(任意)多层介质中弹性波的传播问题。采用与文[1]相同的物理模型和二维FFT算法,给出了任意层数柱状准弹性介质中全波声压波形的计算方法和程序。 对多种参数进行了声压波形的数值计算,考察了串槽对全波波形的影响,着重分析了两个胶结面串槽引起初至波的变化。结果表明,串槽导致套管滑行纵波幅度明显降低,固、流界面的反射波是影响串槽时初至波特征的一个重要机制。更多还原

【Abstract】 The physical model is the same as what was used in ref. [1] and the two dimensions Fast Fourier Transformation algorithm (FFT) is adopted. The evaluation method and program which are used to calculate the full waveform of acoustic pressure in the cylindrical multilayer quasi elastical media is given.The numerical evaluation of the acoustic pressure waveform has been done for many kinds of parameters. The effect of the water layer between two solid media on the waveform is analysed, particularly for the changes of the earlest arrived wave when the cementing interface between casing and cement or cement and formation is broken and there is water between them. The results show that the amplitudes of P and S refracted arrival waves from casing are reduced obviosly when there is water layer between two solid media; and the reflected waves from the interface between solid and fluid is an important mechanism to affect the characters of the esrlest arrived wave.更多还原