Practical Solution of Gas-Flow Equations for Wells and Pipelines with Large Temperature Gradients

Abstract

Published in Petroleum Transactions, AIME, Vol. 207, 1956, pages 281–287. Abstract Rigorous equations for calculating subsurface pressures in flowing and static gas wells, and pressures along horizontal pipelines are presented in this paper. These general equations, based on the mechanical energy balance, contain no assumptions regarding temperature and can be used with either straight-line or curved temperature gradients. The friction factors recommended in this report are based on an absolute roughness of 0.0006 in. Flow is always considered to be turbulent. Although these general flow equations are solved by numerical means, the methods are as convenient as many of those used today to calculate pressures in gas wells and pipelines. These numerical methods are illustrated for flowing and static columns of gas in wells and for flow in pipelines. The authors believe that the use of these methods will result in more accurately calculated pressures in gas wells and pipelines and that the methods are more flexible than any in use at the present time. Also, the methods are easily adaptable to automatic computers. Introduction The problem of calculating subsurface pressures in gas wells and along flowing pipelines has been studied by many investigators with the results that two widely used methods have been presented in technical literature. One approximates conditions in a gas well or pipeline by assuming that temperature and compressibility are constants for the entire gas column.