Simulation of wireline sonic logging measurements acquired with Borehole–Eccentered tools using a high-order adaptive finite-element method

Resumen

The paper introduces a high-order, adaptive finite-element method for simulation of sonic measurements acquired with borehole-eccentered logging instruments. The resulting frequency-domain based algorithm combines a Fourier series expansion in one spatial dimension with a two-dimensional high-order adaptive finite-element method (FEM), and incorporates a perfectly matched layer (PML) for truncation of the computational domain. The simulation method was verified for various model problems, including a comparison to a semi-analytical solution developed specifically for this purpose. Numerical results indicate that for a wireline sonic tool operating in a fast formation, the main propagation modes are insensitive to the distance from the center of the tool to the center of the borehole (eccentricity distance). However, new flexural modes arise with an increase in eccentricity distance. In soft formations, we identify a new dipole tool mode which arises as a result of tool eccentricity.

Autores: Pardo, D., Matuszyk, P., Muga, I., Torres-Verdín, C., Mora, A., Calo, V.

Journal: Journal of Computational Physics

Journal Volume: 230

Journal Issue: 16

Journal Page: 6320–6333

Tipo de publicación: ISI

Fecha de publicación: 2011

Topics: Sonic logging, Adaptive finite element methods, Linear elasto-acoustics, Wave propagation, Non-orthogonal change of coordinates

DOI: http://dx.doi.org/10.1016/j.jcp.2011.04.028

URL de la publicación: https://pdfs.semanticscholar.org/45ed/1095a826933f77ce899e89bfd008f5005d32.pdf