Novel Approaches to the Determination of Archie Parameters I: Simplex Method

Chen, D.S. (The University of Alabama) | Fang, J.H. (The University of Alabama) | Kortright, M.E. (The University of Alabama) | Chen, H.C. (The University of Alabama)



The Nelder-and-Mead simplex method is used to obtain optimal sets of Archie parameters (m, n, a) from resistivity measurements on core samples. This derivative-free optimization method, despite being a local search technique, avoids trapping by minor optima. We have found that the method is very effective, highly efficaceous, and easily implemented on a PC. The agreement between the results obtained from this method and those from the nonlinear least-squares approach is remarkable.