Application of Wilcoxon generalized radial basis function network for prediction of natural gas compressibility factor

Gas compressibility factor is necessary in most of chemical and petroleum engineering calculations. Accurate and fast calculation of this property is of a vital importance in a large number of simulators used in petroleum and gas engineering. In this study, a large data bank (978 data points), covering a wide range of natural gases, was collected from open literature sources. Afterwards, one of the newest and most powerful modeling approach, namely Wilcoxon generalized radial basis function network (WGRBFN) was employed to predict the compressibility factor of natural gases. The results obtained from the proposed model were compared to those of nine empirical correlations and five equations of state. Statistical and graphical error analyses demonstrated that the developed model can satisfactorily predict the compressibility factor of natural gases with an average absolute percent relative error of 2.3%. Moreover, it was demonstrated that the proposed model outperforms all of the studied empirical correlations and equations of state. Finally, to identify the probable outliers the Leverage approach was performed. All of the experimental data seem to be reliable except 2%. Therefore, the developed model is reliable for the prediction of natural gas compressibility factor in its applicability domain. (C) 2015 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.