TITLE:
Influence of the Chemical Composition of Completion Fluids on the Propagation of Electromagnetic Waves within Oil Wells
AUTHORS:
Alexandre Ashade Lassance Cunha, Marco Aurélio Pacheco, José Ricardo Bergmann
KEYWORDS:
Electromagnetism; Oil Well; Wireless Telemetry; Monte-Carlo; Uncertainties; Heterogeneous Media
JOURNAL NAME:
Engineering,
Vol.4 No.12A,
December
31,
2012
ABSTRACT: The propagation of
electromagnetic waves in the annular region of oil wells was studied. The
present study aims to analyse the propagation attenuation along the well, as
well as the input impedance determined by a source placed near the wellhead. A
coaxial waveguide model was adopted with heterogeneous dielectrics and losses.
First, a wave equation solution for the waveguide is presented, assuming a
homogeneous medium with losses, by solving the equation in cylindrical
coordinates using the vector potential technique. An uncertainty analysis model
is then developed to model the heterogeneous characteristics of the medium. Monte Carlo simulations were performed with the created
model using data gathered from the literature. The results of the simulations
indicate that propagation in the transverse electromagnetic mode has the
smallest attenuation and that for depths of up to 4000 m, there is an attenuation of less than 52 dB. Furthermore, the input impedance
ranges from 10 Ω to 10 kΩ because of the uncertainties involved in the problem
in question.