Finitedifference (FD) method for 3D simulation of sonic waves propagating in a borehole and surrounding 3D heterogeneous elastic medium is presented. It is based on explicit secondorder staggered grid FD scheme that solves the firstorder elastic wave equations in cylindrical coordinates. Special modification of Perfectly Matched Layer (PML) for cylindrical coordinate system is developed and implemented. Essential 3D nature of the waves processes for realistic models claims necessity to use parallel computations. Parallelization is performed on the base of domain decomposition approach and implemented under Message Passing Interface (MPI). Result of numerical experiments is presented.