Journal of Geology & Geophysics
Open Access
ISSN: 2381-8719
+44 1478 350008
ISSN: 2381-8719
+44 1478 350008
Raj Mittra
University Park, PA-16802
Tanzania
Research Article
Low Frequency Modelling of Layered Media for Logging While Drilling Applications Using FDTD
Author(s): Kadappan Panayappan, Sidharath Jain, Raj Mittra and Jaideva C. GoswamiKadappan Panayappan, Sidharath Jain, Raj Mittra and Jaideva C. Goswami
In a typical Logging While Drilling (LWD) ap- plication, several coils operating in the frequency range of a few KHz to MHz are used as transmitters and receivers to appropriately characterize the earth formation. Electromagnetic modelling of such a low frequency system poses serious computational challenges. In the Method of Moment (MoM) formulation, contribution of vector potential to the total field becomes several orders of magnitude smaller than that of the scalar potential, thus making the resultant matrix highly ill-conditioned. Finite Difference Time Domain (FDTD) method, on the other hand, requires enormous number of time steps to capture the low frequency information. In this paper, we consider a layered-earth model and compute the electromagnetic field due to electric and magnetic dipoles embedded in the formation. To address the low frequency problem in FDTD, we consider t.. View More»
DOI:
10.4172/2381-8719.1000201