3d Finite Difference Simulations of Acoustic Logs in Tilted Layered Porous Formations

Abstract

A finite-difference algorithm is developed in the 3D cylindrical coordinate system. Synthetic waveforms excited by monopole and dipole acoustic sources are calculated for acoustic logging in a tilted layered formation composed of two poroelastic media. It is revealed that the existence of a tilted layer drives more acoustic energy out and therefore reduces the reflection back to the wellbore. Numerical results show that the amplitudes and the arrival times of the shear waves and flexural modes are influenced by the borehole inclination. The Stoneley modes, however, show little sensitivity to the orientation of the layer interface.

Effects of confining pressure and pore pressure on multipole borehole acoustic field in fluid-saturated porous media

“…Guan and Hu [32] employed the timedomain finite difference algorithm to simulate acoustic well logging responses to horizontally layered porous formations. He et al [33,34] employed three-dimensional finite-difference simulations to model inclined layered porous formations and porous elastic formations with anisotropic magnetic permeability. Peng et al [35] analyzed the acoustic wave propagation and wellbore acoustic fields in non-uniform porous media saturated with viscous fluid.…”