Improved Multiphase Flow Rate Models for Chokes in the Algerian HMD Oil Field

Accurate prediction of multiphase flow rate is of prime importance in controlling production of oil fields. Direct measurements using multiphase meters are time-consuming and very costly. On the other hand, none of the published models can be considered as a universal model and most of these models are designated only for the critical flow. The aim of this study is to develop and validate practical models for the Algerian Hassi Messaoud (HMD) oil field covering both critical and subcritical multiphase flows through chokes of naturally flowing and gas lift wells. The new choke models are developed on the basis of the Gilbert model by incorporating the downstream pressure of the choke under the subcritical conditions. A large data set is used to evaluate the new models and to compare their performance with previously published prediction models. These data are divided, for each flow regime, into five selected categories based on the gas–oil ratio and a nonlinear regression algorithm is implemented to validate the new models. The comparison revealed the accuracy of two new models that improved the predicted production rates of the current model of HMD field in 130 wells out of 174 and the sum of absolute differences between the measured and the predicted oil flow rates (SAD) was reduced by 16.68% on 6,786 measurements. For the wells that are assisted with gas lift, the predictability was improved considerably: There was improvement in 85 wells out of 93 and the SAD was reduced by 42.11% on 2,317 measurements.