Dual-iterative model for gas condensate measurement based on void fraction

Abstract

Gas condensate frequently appears in the production of natural gas, and the accurate measurement of this gas–liquid flow, known as wet gas, plays an increasingly significant role in the present age. This study proposed a novel model to measure wet gas based on the void fraction and the Lockhart–Martinelli (L–M) parameter. A vital parameter in two phase flow, the void fraction is not often used in wet gas models because it is difficult to measure. The proposed dual-iterative model attempts to ease this calculation by using an iterative algorithm to obtain the gas phase flow rate. Another complication of existing wet gas correlations is that they require the liquid flow rate to measure the gas flow rate, but this approach is impractical in industrial environments. The proposed dual-iterative model, however, only requires differential pressure ratios and two phase densities, which can be measured accurately and easily. Laboratory results indicate that the relative deviations of the dual-iterative model range from −5.92% to 5.36% with a standard deviation of 1.56%. An on-site test to verify the applicability of the model was conducted at the Petro China's Tarim Oilfield Company and resulted in relative deviations from the cumulative predicted gas flow rate below 5.2% for every well tested.