Application of numerical methods in electromagnetic wave well-logging problems

摘要

The introduction of numerical methods in Electromagnetic Theory has solved, a number of problems which conventional or analytical methods failed. Electromagnetic wave well-logging is an important application of Electromagnetics. As EM waves penetrate the stratified media, the phase difference and amplitude ratio which well-logging tool measures vary [1]. FEM [2] and BEM [3] are applied to the simulation of Radio-frequenoy well-logging curve in this paper to enhance the numerical methods of well-logging analysis. A memory-saving FEM algorithm is derived and programmed. The results are in good agreement with those obtained by other methods. For stratified and inhomogeneous media FEN grid varies little, so the cpu time and storage required are about the same. This is the disadvantage of FEU. BEM can be used to treat the stratified case specifically and the numerical solutions are acceptable compared with analytic solutions. [8].