Multiphase-flow choke correlation limits analyzed

An evaluation shows the limitations of seven correlations for determining flow rate of multiphase fluids through restrictions. No single correlation is best for all ranges of flow variables, but in this evaluation the best overall comparison was obtained with the Gilbert, Ros, and Poettmann and Beck correlations. A number of published correlations, both analytical and empirical, are available to assess multiphase flow through restrictions. Besides the three previously mentioned, four other correlations in use today are those by Ashford, Omana, Achong, and Baxendell. This evaluation reviews these seven correlations using production data from 181 well tests. Statistical analysis is used to determine the strengths and weaknesses of each correlation and to develop practical guidelines that a production engineer can use to choose the proper correlation for a particular circumstance. Also examined are the effects of several flow variables such as pressure ranges, producing gas/liquid ratios, restriction sizes, liquid flow rates, and flowing oil API gravity.