Drop size, liquid holdup, and pressure drop have been measured
simultaneously in real time. This experiment was carried out with air/water to
establish annular two-phase flow on a 0.019-m-internal-diameter vertical pipe
(7-m-long multiphase-flow facility). Drop concentration, distribution, and
sizes in the core flow were measured using Spraytec, a light-diffraction-based
Liquid holdup was logged with pairs of flush-mounted ring-conductance probes
at various positions within the test section. Pressure drop was monitored using
a differential-pressure meter mounted between two pressure taps separated by a
distance of 1.5 m.
Subtle changes were observed in the characteristic drop diameters around gas
superficial velocities of 21 and 30 m/s following progressive, systematic
increase in gas and liquid superficial velocities. The gas superficial
velocities at which these changes were observed have been linked with
transition boundaries to cocurrent and mist annular flows, respectively.
Corresponding similar pseudochanges, finger-rinted in the liquid-holdup and
pressure-drop data at these transition boundaries, in addition to film and
drop-flow reversals captured on video, make the evidence more compelling.
Applicability of core-flow dynamic data to explain various physical processes
associated with gas-well liquid loading has been demonstrated.
© 2012. Society of Petroleum Engineers
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- Original manuscript received:
28 October 2010
- Revised manuscript received:
29 August 2011
- Manuscript approved:
14 September 2011
- Published online:
16 January 2012
- Version of record:
13 March 2012