A simple predictive tool to estimate flow coefficient for subsonic natural gas flow through nozzle-type chokes

In this work a simple-to-use method is developed to estimate the choke flow coefficient for natural gas subsonic flow through nozzle-type chokes as a function of Reynolds number and the ratio of choke diameter to pipe diameter. The results can be used in follow-up calculations for rapid estimation of gas passage through a choke under subsonic flow conditions for Reynolds number and the ratio of choke diameter to pipe diameter between 0.4 and 0.75. Estimations are found to be in excellent agreement with reported data in the literature with average absolute deviation being less than 0.3%. The tool developed in this study can be of immense practical value for petroleum engineers to have a quick check of gas flow through chokes at various conditions without opting for any field trials. In particular, engineers would find the approach to be user-friendly with transparent calculations involving no complex expressions. (C) 2012 Elsevier B.V. All rights reserved.