On the theory of local acoustic probing of borehole zones in rocks

A theory of local probing of borehole zones in porous and permeable rocks by means of acoustic waves is developed. Acoustic signals are assumed to propagate in an annular gap between the probe body and porous permeable wall of the borehole. Quantitative characteristics and special features of wave dynamics depending on the character of inhomogeneity of the porous medium are considered, in particular, in the case with radial fractures or a poorly permeable “crust” around the channel. The results obtained show that permeability and porosity of rocks in some cases exert a significant effect on evolution of acoustic signals in the borehole.