Paper Info
Title
Three-dimensional simulation of eccentric LWD tool response in boreholes through dipping formations
Abstract
We simulate the response of logging-while-drilling (LWD) tools in complex thee-dimensional (3-D) borehole environments using a finite-difference time-domain (FDTD) scheme in cylindrical coordinates. Several techniques are applied to the FDTD algorithm to improve the computational efficiency and the modeling accuracy of more arbitrary geometries/media in well-logging problems: (1) a 3-D FDTD cylindrical grid to avoid staircasing discretization errors in the transmitter, receiver, and mandrel geometries; (2) an anisotropic-medium (unsplit) perfectly matched layer (PML) absorbing boundary condition in cylindrical coordinates is applied to the FDTD algorithm, leading to more compact grids and reduced memory requirements; (3) a simple and efficient algorithm is employed to extract frequency-domain data (phase and amplitude) from early-time FDTD data; (4) permittivity scaling is applied to overcome the Courant limit of FDTD and allow faster simulations of lower frequency tool; and (5) two locally conformal FDTD (LC-FDTD) techniques are applied to better simulate the response of logging tools in eccentric boreholes. We validate the FDTD results against the numerical mode matching method for problems where the latter is applicable, and against pseudoanalytical results for eccentric borehole problems. The comparisons show very good agreement. Results from 3-D borehole problems involving eccentric tools and dipping beds simultaneously are also included to demonstrate the robustness of the method.
Year
DOI
Venue
2005
10.1109/TGRS.2004.841354
IEEE T. Geoscience and Remote Sensing
Keywords
Field
DocType
index terms—borehole problem,numerical mode matching method,well logging,oil drilling,dipping formations,finite-difference time-domain scheme,well logging problems,geophysical prospecting,absorbing boundary condition,well-logging.,computational efficiency,memory requirements,staircasing discretization errors,borehole problem,logging-while-drilling lwd tool,finite-difference time-domain fdtd method,arbitrary media,perfectly matched layer,permittivity scaling,arbitrary geometry,courant limit,tool response,cylindrical coordinates,mandrel geometry,3d borehole environments,oil explo- ration,oil exploration,finite difference time-domain analysis,logging-while-drilling tools,3d simulation,modeling accuracy,anisotropic medium,finite difference time domain,indexing terms,frequency domain,three dimensional
Discretization,Cylindrical coordinate system,Robustness (computer science),Finite-difference time-domain method,Artificial intelligence,Perfectly matched layer,Computer vision,Boundary value problem,Cylinder,Optics,Conformal map,Acoustics,Mathematics
Journal
Volume
Issue
ISSN
43
2
0196-2892
Citations 
PageRank 
References 
17
2.26
6
Authors
4
Name
Order
Citations
PageRank
Yik-Kiong Hue1263.35
Fernando L. Teixeira29716.97
Luis San Martin3172.26
Michael S. Bittar4252.94