Analysis and design of magnet and antenna for NMR well-logging tool

Author

Goswami, J.C. ; Luong, B. ; Sezginer, A. ; Oldigs, R.

Author_Institution

Sugar Land Product Center, Schlumberger Oilfield Services, Houston, TX, USA

Volume

2

fYear

1999

fDate

11-16 July 1999

Firstpage

760

Abstract

We analyze the performance of a saddle-point nuclear magnetic resonance (NMR) well-logging tool proposed by Kleinberg, Sezginer and Griffin (1992). A perturbation technique in conjunction with the finite element method (FEM) is used to evaluate the antenna efficiency. The static magnetic field due to a permanent magnet in the presence of ferrites is evaluated by using nonlinear magnetostatic FEM. Comparisons of the computed and measured results indicate a very good match. The present approach has proved to be quite efficient and accurate in the design of an NMR sensor. A typical inside-out NMR tool for oilfield measurement is shown.

Keywords

antennas; ferrites; finite element analysis; magnetic fields; magnetic sensors; magnetostatics; nuclear magnetic resonance; oil technology; permanent magnets; perturbation techniques; NMR sensor; NMR well-logging tool; antenna analysis; antenna design; antenna efficiency; ferrites; finite element method; magnet analysis; magnet design; measured results; nonlinear magnetostatic FEM; oilfield measurement; performance analysis; permanent magnet; perturbation technique; saddle-point; static magnetic field; Ferrites; Finite element methods; Magnetic analysis; Magnetic field measurement; Magnetic resonance; Magnetostatics; Nuclear magnetic resonance; Performance analysis; Permanent magnets; Perturbation methods;

fLanguage

English

Publisher

ieee

Conference_Titel

Antennas and Propagation Society International Symposium, 1999. IEEE

Conference_Location

Orlando, FL, USA

Print_ISBN

0-7803-5639-x

Type

conf

DOI

10.1109/APS.1999.789425

Filename

789425