Study on the wave amplitude of radial P-wave velocity profile

Formation alteration is a common phenomenon in the process of oil-gas development. Lots of research has been done on the situation where radial velocity changes. Most of them focused on the dispersion characteristics of acoustic waves propagation. In this paper, we study the amplitude variation of the P-wave in the radially layered formation model, whose elastic wave velocity changes from the near-well zone to the area far away from the well. Monopole is used as the acoustic source. We establish different formation models with multiple coaxial cylindrical layers. Through compare the waveforms of different models with different wave velocity variation, we found that the velocity difference between adjacent layer instead the number of layers is the main reason to amplitude change. By analyzing the waveform amplitude and studying the mechanism of borehole-acoustic wave propagation, we can provide theoretical reference for the data processing.