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High liquid content is obtained in the T-junction side arm, which affects the operational performance of downstream equipment installed in offshore petroleum industries. Diameter ratio, velocity ratio, and side arm angle of T-junction play dynamic role to control phase redistribution. The effect of these parameters on liquid take-offs is unclear from literature, without any agreement among researchers. Literature only provides empirical correlations valid for one specific application for which the correlations were developed. There is a dire need of correlations with high accuracies to conclude the effect of a certain variable on liquid carryovers based on available data. Objectives of this study are to collect data from multiple research publications, develop easy to use correlations, and to study parameters response surfaces. Plot digitization and Design Expert software are utilized for data collection and statistical analysis, respectively. Results depicted that phase separation improves by reducing diameter ratio to 0.33 and upward inclined side arm. Furthermore, liquid carryovers escalate by increasing velocity ratio and decrease at higher velocity ratios. This research study is first attempt in last few decades which is based on collection of data from different experimentation facilities and eliminating confusions among researchers about effect of parameters on phase separation. [ABSTRACT FROM AUTHOR]

Abstract T-junctions are often used in offshore platforms to partially separate gas from produced fluids. Poorly designed T-junctions frequently produce very high liquid (oil and/or water) carryovers, causing major issues to the downstream equipment train which is not designed to handle excessive liquid. This paper reports the liquid carryover experiments in T-junctions using five different side to main arm diameter ratios under slug flow regime. The obtained phase separation curves can be divided into two component variables; liquid-carryover threshold and peak liquid carryover. The experiments demonstrate that with a decrease in diameter ratio both of these variables decrease. Yet, for superior multiphase flow separation, a high liquid carryover threshold and a low peak liquid carryover are required. Hence, the generally accepted rule that a reduction in diameter ratio improves the phase separation is revealed to be an over-extrapolated statement. The novel findings of this work are: 1) for optimum flow splitting under slug flow conditions, the diameter ratio should be kept between 1 and 0.67, while the diameter ratio 0.67 was found to be most suitable; 2) two correlations were developed for predicting two-phase slug flow separation in different diameter ratio T-junctions. These correlations offer beneficial guidance and clarifications for a number of oil and gas flowline and pipeline applications. Highlights • Separation of two-phase slug flow was experimentally analyzed in five T-junction diameter ratios. • T-junction diameter ratio can only be reduced up to a limit, for improving phase separation. • Two correlations were presented to determine the side arm extraction of operating phases. [ABSTRACT FROM AUTHOR]

Despite its modest construction, T-junctions have been used as a partial phase separator in various industries for decades. To this date, the prediction of phase maldistribution at a pipe junction is a serious concern, as oftentimes very high liquid carryovers are received, affecting the operation of downstream equipment. This not only results in unforeseen maintenance, but also in the loss of operational time and cost. To address this matter, a study is reported in which experiments were conducted on five distinct diameter ratio T-junctions under stratified-wavy and slug flow conditions. From the collected data, six numerical correlations were prepared to estimate the side arm extraction of gas and liquid, as well as the pressure at main and side arm outlets of the T-junction. It was found that predictions from present equations concede reasonably well with the experimental results. [ABSTRACT FROM AUTHOR]

Most of the research carried out on reduced diameter ratio T-junctions concluded that partial phase separation can be improved by decreasing the diameter ratio. Despite using very small diameter ratio T-junctions, petroleum industry has always faced the problem of continuous and sometimes very high liquid carryovers. In this regard, the separation of air-water stratified-wavy flow in 1.0, 0.52, 0.67, 0.27 and 0.20 diameter ratio T-junctions was examined to investigate the effect of diameter ratio on phase separation. Phase distribution of each T-junction was evaluated by observing the point at which liquid carryover starts (liquid carryover threshold) and the maximum liquid carryover delivered (peak liquid carryover). For optimum separation it is essential that liquid carryover threshold is high and peak liquid carryover is low, however these parameters were found to decrease with the reduction in diameter ratio. It was observed that in stratified-wavy flow, the drop in liquid carryover threshold was reasonable and thus in this flow regime a decrease in diameter ratio was always found to enhance phase separation. Two correlations were also developed to predict the phase splitting behavior, under a wide range of operating conditions. [ABSTRACT FROM AUTHOR]