Electromagnetic field generated by an off-axis source in a cylindrically layered medium with an arbitrary number of horizontal discontinuities
- Schlumberger-Doll Research, Ridgefield, CT (United States)
The authors investigate the propagation of electromagnetic waves in a cylindrically layered medium with an arbitrary number of horizontal discontinuities. The dielectric constant, conductivity, and magnetic permeability of the medium are functions of [rho] and z only, but the field generated by an off-axis source in this medium is in general a function of [rho], [sigma], and z. This two and a half-dimensional (2.5-D) problem is often encountered in electromagnetic well logging, as well as in other areas such as optical fiber communications and integrated optics. They show that a coupling exists between the transverse electric (TE) and transverse magnetic (TM) components of the field even in the absence of the horizontal discontinuities, which makes it difficult to solve for the field. They apply an efficient numerical mode-matching (NMM) algorithm to tackle this 2.5-D problem. This algorithm uses the local reflection and transmission operators developed in the recent work on the diffraction of non axisymmetric waves in a cylindrically layered medium with a single horizontal discontinuity. For several special geometries, they compare the numerical results from this NMM algorithm with analytical solutions as well as the earlier numerical results for axisymmetric cases, and found excellent agreement between them. As an application to the geophysical subsurface sensing, solve several practical problems, and find that a large eccentricity effect can occur in realistic electromagnetic well logging. Conventional log interpretation methods cannot adequately account for these effects. With the NMM algorithm developed here, all these different effects can be accounted for simultaneously and accurately.
- OSTI ID:
- 6111397
- Journal Information:
- Geophysics; (United States), Vol. 58:5; ISSN 0016-8033
- Country of Publication:
- United States
- Language:
- English
Similar Records
Stresses, strains, and displacements in a poroelastic layered pavement model subject to a moving load
The crosswell electromagnetic response of layered media
Related Subjects
02 PETROLEUM
03 NATURAL GAS
ELECTRIC LOGGING
DATA ANALYSIS
EXPLORATORY WELLS
RESERVOIR ROCK
DIELECTRIC PROPERTIES
ELECTRIC CONDUCTIVITY
CORRECTIONS
ELECTRIC FIELDS
ELECTROMAGNETIC RADIATION
GEOLOGIC STRATA
MAGNETIC FIELDS
NATURAL GAS WELLS
OIL WELLS
WAVE PROPAGATION
ELECTRICAL PROPERTIES
GEOLOGIC STRUCTURES
PHYSICAL PROPERTIES
RADIATIONS
WELL LOGGING
WELLS
580000* - Geosciences
020200 - Petroleum- Reserves
Geology
& Exploration
030200 - Natural Gas- Reserves
Geology
& Exploration