Analysis of subcritical multiphase flow through wellhead chokes.

This work presents the evaluation of the theoretical models and empirical correlations for the prediction of multiphase flow rate through wellhead chokes in subcritical conditions. First, literature review was conducted to have a comprehensive understanding of problem and areas that needed to be improved. Then selected existing models, correlations and slip correlations are studied to determine which of them gives the best prediction relative stability and accuracy, evaluating and comparing the flow data tests with three different errors parameters: absolute errors, relative errors and standard deviation. Before generating results, all selected models and correlations are tested by using the same database. Models and correlations were compared with three different errors parameters: absolute errors, relative errors and standard deviations. Before generating results, all selected model and correlations are tested by using the same flow data base. The database that we have built is considered very representative with wide ranges of oil rates, pressures, GOR, choke size and fluid characteristics. The flow tests are manily from Norway, Angola, Italy and Nigeria fields. This thesis work evaluates Sachdeva et al. and Perkins model, Gilbert equation and two semi-analytical models chosen after an accurate analysis of the literature (Kargarpour model). Additionally, this study proposes a new empirical correlation (De ghetto Equation) and modifications conducted on Sachdeva model and Gilbert equation. This is the added value of this work.