Page 479 - Standard Handbook Petroleum Natural Gas Engineering VOLUME2

Flow of Fluids 435

presented flow-pattern and flow-regime maps in which various areas are indicated
on a graph for which there are two independent coordinates. Maps are also
dependent on ranges of pipe inclination from vertical upward to vertical
downward [19]. Selection of the appropriate flow regime map is based solely
on the pipe segment inclincation 8 from the horizontal, as shown below:

Range of lnclinatlon from the Horizontal Regime Maps

e = 900 to 150 Upward inclined
e = 150 to-io0 Near horizontal
e = -1 00 to -900 Downward inclined

Flow Regimes

The steps in the determination of the flow regime are as follows:
1. Calculate dimensionless parameters.
2. Refer to flow regime maps laid out in coordinates of these parameters.
3. Determine the flow regime by locating the operating point on the flow
regime map.
The discussions in the following sections treat the flow regime maps for
vertical upward (e = 90"); slightly inclined (0 = 15" to -10") and vertical
downward inclinations.
To proceed with the calculations of the flow regime, it is necessary to calculate
the superficial velocities for each flow phase. The superficial velocities for the
gas, oil and water are

(6-65~)

(6-653)
v, = qPp (6-65c)

where A, = pipe flow area in ft2
q = volumetric flowrate at flow conditions in ft3/s

The superficial velocities of liquid phase (oil and water) are calculated as
(6-65d)

The mixture velocity that will be used in some of the calculations is the sum
of the superficial velocities of the gas and the liquid phases:
(6-65e)

The average velocity of each phase is related to the superficial velocity through
the liquid holdup:
U, = vL = vsJHL (6-658