Infinite element method for solving open boundary field problem and its application in resitivity well-logging
WithZ. Tang, J. Yuan, J. Zhu &W.Yan
Pages 5

TheNMMmethod is an efficient algorithmwhich is widely used inwell-logging calculation.When the 2-D distribution ofmedium is arbitrary in every layer, a 3-D NMMmethod is introduced in Fan & Liu (2000). This method established and solved the generalized eigenvalue matrices by the 2-D FEM problem of every layer at first, then a series analytical formula are formed in z direction to calculate the field of the whole domain. This method is much faster than 3-D FEM since it decomposes the 3-D solution to a series of 2-D eigenvalue solutions. However, the eigenvalue matrix of each layer is formed by general 2-D FEM and a large calculation domain is selected, as a result, a truncate error is not avoidable and large number of FEM nodes are generated.