An investigation into sub-critical choke flow performance in high rate gas condensate wells

Abstract

There are some correlations in the literature to predict the gas and liquid flow rate through wellhead chokes under subcritical flow condition. Majority of these empirical correlations are developed based on limited production data sets that were collected from a small number of fields. Therefore these correlations are valid within the parameters’ variation ranges of those fields. If such correlations are used elsewhere for the prediction of the subcritical choke flow performance of the
other fields, this will lead to significant errors. Additionally, there are only a few empirical correlations for sub-critical choke flow performance in high rate gas condensate wells. These led the authors toward developing a new empirical correlation based on a wider production data set from different gas condensate fields in the world. 234 production data points were collected from a large number of production wells in twenty different gas condensate fields with diverse reservoir
conditions and different production history. Non-linear regression analysis method is applied to the production. The new correlation is validated with a new set of data points from some other production wells to confirm the accuracy of the established correlation. The results show that the new correlation had minimal errors and predicted the gas flow rate more accurately compared to the other three existing models over a wider range of the parameters’ variation ranges.