Известия Томского политехнического университета: Инжиниринг георесурсов (Apr 2018)
Experimental study of two-phase flow in vertical tube in gas lift mode
Abstract
Relevance. The problem of robust design of gas lift is now very important in connection with the widespread use of this method for oil production, development of airlifts to transport pulp, mineral extraction from the seabed and other applications. The action mechanism of gas lift systems is not entirely clear, since it is held under complex conditions, at different orientations of pipe and long lengths, with variable physical properties of the phases in the changing flow regimes. The main aim of the study is the experimental investigation of gas-liquid flow in vertical tube (gas lift regime), using a laser Doppler anemometer with optical fiber probe, measurement of velocity and concentration profiles in the tube cross section. The research methods: Laser Doppler anemometer with optical fiber probe to measure velocity and concentration profiles of a gas phase in the tube cross section. The results. Theauthor has studied the efficiency of gas lift and gas-liquid flow structure in a vertical pipe employing a laser Doppler anemometer with fiber-optical probe. Three specific zones can be distinguished in the cross section of the gas-liquid flow. In contrast to the wall area with minimum values of the parameters, the velocity and concentration of the gas phase in the transition zone are increasing sharply, further they are increasing smoothly to a maximum in the central zone. The gas lift is characterized mainly by slug regime, the liquid rises in the plugs between the large bubbles. Velocity of the large bubbles top and bottom borders in the central zone of tube is the same, but in the transition zone the velocity of the top border slows down, while at the bottom border, on the contrary, it is accelerated by falling liquid film. The velocity of small bubbles in the center and transition zones is the same.
