Pseudo interface waves can exist at the interface of a fluid and a fluid-saturated poroelastic solid. These waves are typically related to the pseudo-Rayleigh pole and the pseudo-Stoneley pole in the complex slowness plane. It is found that each of these two poles can contribute (as a residue) to a full transient wave motion when the corresponding Fourier integral is computed on the principal R...

The amplitude of sound scattered from submerged elastic objects is dominated by resonance phenomena corresponding to the mechanical eigenvibrations of the object. It is often difficult to predict the resonance frequencies of bounded elastic targets using exact methods. It has been shown, however, that resonances arise due to phase matching of circumferential waves traveling over the object surf...

In this paper, a finite element approach is applied to study the dispersion properties of non-leaky acoustic waves inside boreholes with off-centered LWD (logging while drilling) tools. Both soft and hard formation cases are studied with focus on phase velocity dispersions of Stoneley, dipole and quadrupole modes. When an LWD tool is off-centered, the dispersion curve of the Stoneley mode shift...

The wavefields generated by monopole and dipole sources in a fluid filled borehole embedded in multilayered transversely isotropic saturated porous formations are studied. The layers are modeled following Biot theory modified in accordance with homogenization theory. It allows to take into account a transversely isotropic skeleton and/or a transversely isotropic complex permeability tensor. The...

The propagation of seismic waves in an open borehole is reviewed. The principal wave types are the refracted P and S waves and the two guided waves pseudo-Rayleigh and Stoneley. The dispersion properties of the gUided waves are analyzed. An efficient method of computing synthetic microseismograms is described. The relative effects of the borehole. fluid and formation properties on the propagati...

3677 Scholte-Stoneley waves (SSW) propagate at the interface of a fluid medium and a solid medium. They have a velocity smaller than the transverse and longitudinal velocities in the solid, and smaller than the sound velocity in the fluid. They are thus doubly evanescent and propagate without loss along the interface. They were observed for periodically corrugated surfaces in contact with water...

The classical solution for the Scholte wave along a fluid and isotropic substrate .s well known. However, when the subshate is either a weakly anisotropic solid, or the adjoining fitrid is subject o a hydrostatic pressure, the analysis of Scholte wave propagation becomes rather complex and lengthy computations are required to obtain the solution. The purpose of this paper is to apply simple and...

There has recently been considerable interest in the acoustics of fluid-saturated porous media. The most interesting peculiarity, the existence of two compressional waves, was first predicted by Biot [1] in 1956. It was not until 1980 that Plona [2] experimentally observed the additional slow compressional bulk wave in a water-saturated porous solid composed of sintered glass spheres. Even more...

The seismoelectric logging method is based on measuring the electric field generated by seismic waves in a fluid-filled borehole. Two kinds of electromagnetic (EM) fields can be generated within the formation and at the interface of formations. One is a stationary or local EM wave and the other is a radiating EM wave. In this paper, we make various fractured borehole models with artificial mate...