Distribution of acoustic wavefield in boreholes and rock formations

The acoustic wavefield in a borehole and rock formation recorded during the sonic logging is stil a subject of interest to researchers in view of the construction of new instruments and the developement of interpretation methods. The recording of acoustic full wavetrains using elongated devices (Long Spaced Sonic produced by Halliburton Company) in Poland enables us to determine the elastic and reservoir parameters of rocks in natural cinditions (in situ). The introduction of acoustic devices with dipole sources into the fiels practice over the world makes it possible to attain an easier identification of the shear waves in the acoustic full wavetrains in selected geological conditions. The results of modelling aimed to illustrate the influence of different geological parameters on the kinematic and dynamic features of the acoustic wavetrains recorded with long space sonic devices are presented. A comparison of the acoustic full wavetrains modelled with the monopole and the dipole sources is also performed.