Page 465 - Handbook Of Multiphase Flow Assurance

Units and conversions 465

Gravity driven flow is characterized by Froude (pronounced fru:d) formula
Fr = v/(g D)^0.5.
Fr < 1 stratified smooth.
Fr < 2 stratified wavy.
Fr > 2 stratified mist.
Fr > 12 mist.
Froude allows an important insight at energies of entrainment and deposition. V = 2√gD
is a transition where flowing gas starts to entrain liquid. This may be of use for TOLC corro-
sion inhibition.
Flow correlations applicability to vertical or horizontal flow is shown in Table 14.10.

Monitoring and instrumentation for flow assurance

Possible locations for produced fluids monitoring instrumentation are shown in Table 14.11.

Units and conversions

Acceleration of gravity (standard) near 45° latitude; gravity near equator is 0.25% less and
gravity in polar regions is 0.25% more.
2
g = 32.17 ft/s = 9.807 m/s 2
Avogadro's number
23
N A = 6.023 * 10 molecules/g-mole
Newton's conversion constant
2
g c = 32.17 lbm-ft/lbf s = 1.000 kg m/N s 2
TABLE 14.10 Flow correlations applicability to vertical or horizontal flow
Near-vertical
liquid Inclined liquid Near-horizontal Near-vertical Near-horizontal
dominated dominated liquid gas dominated gas dominated
flow flow dominated flow flow flow
Ansari + − + − −
Beggs and Brill + + + + +
Duns & Ross + + + + +
Govier, Aziz and + + + + +
Forgasi
Gray − − + − −
Hagedorn and Brown + − + − −
Mukherjee and Brill + + + + +
Oliemans − − − + +
Orkiszewski + − + − −