An Improved Method for Calculating Bottomhole Pressures in Flowing Gas Wells With Liquid Present

Abstract

Summary A method is presented for calculating bottomhole pressures (BHP's) from wellhead measurements in flowing gas wells with liquid present in the well stream. This method, a modification of existing methods, is based on including the contribution of entrained liquid to gravitational gradients. The study also includes evaluation of effective roughness factors evident from actual flowing pressure data. The proposed method was tested vs. both a two-phase flow model developed by Govier and Fogarasi1 and currently applied methods based on dry-gas wells. The method was also tested with Govier and Fogarasi's data from 94 flowing wells and with data from 50 wells from the public files of the Texas Railroad Commission. The new method compared favorably with the two-phase flow model and was superior to currently applied methods.