3 Phase Separator spreadsheet

EXAMPLE 4: SIZE A 3-PHASE HORIZONTAL SEPARATOR Gas Flowrate (MMSCFD) 0.01 Gas MW Oil Flowrate (BOPD) 60 Oil S.G. W ater Flowrate (BW PD) 100 W ater S.G. Total Liquid (BPD) 160.00  ATM Press. 14.7 Op Press (psig) 50.00 Op Temp (F) 120 Gas Compressibility Z 0.89 Retention Time (min) t 3.00 Remove drops >__micron from gas 150 Remove H2O drops >__micron from oil 500 Remove oil drops >__micron from H2O 200 Vessel Liquid Level - beta 50%

1. Calculate design design specification information rg = (P+Pa)(MW) 10.73*(T+460)*(z) rl = 62.4(sp. gr.) rw = 62.4(sp. Gr H2O.) Dp= 0.00003937(micron)/12 Dw= 0.00003937(micron)/12 Do = 0.00003937(micron)/12 m=MMSCFD(1e6)(MW) 379.4(24)(3600) Qa=m/rg Ql Qw Qm=Qa+Ql+Qw pm=(rl*Ql+rg*Qg+rw*Qw)/Qm Fractional area of liquids - alpha

0.27

lb/cu ft

49.92 62.40 0.000492 0.001640 0.000656 0.01

lb/cu ft lb/cu ft ft ft ft lb/sec

0.03 0.0039 0.0065 0.04 15.97 0.50

23 0.8 1

acfs cu ft/sec cu ft/sec cu ft/sec lb/cu ft

2. Calculate C D and min diameter  Trial No.  Assume C D

1 2.01

2 2.02

3 2.02

Vt = (4gDp(rl-rg)/3CDrg)^0.5

1.39

1.39

1.39

22.86

22.82

22.81

2.02

2.02

2.02

Re = 1488(D pVtrg)/m Calculated CD Minimum dia.= 12*(TZQg/2.4Vt(P+Pa))^0.5

3. Determine the fractional height of water in the vessel  Fractional area of water aw=atQw/t(Qw+Ql) 0.313 Fractional height of water  bw 0.35 .350 Fractional area of water aw 0.312 4. Calculate max vessel diameter for water settling  Vtw = 1488gDw2(pw-pl)/18ml 0.08 Max Height of Oil Pad, Ho 165.04 Maximum diameter = Ho/(b -b w) 1100

1.9 in

6

change un until til ab above ma matches be bel

ft/sec in max in max

5. Calculate max vessel diameter for oil settling  Vtw = 1488gDw2(pw-pl)/18mw Max Height of water, Hw Maximum diameter = Hw/bw Maximum Vessel Diameter

0.0207 44.77 128

ft/sec in max in max

128

126

6. Calculate vessel gas and liquid capacity requirements dvLeff (for gas capacity) 0.30 dv^2*Leff (for liquid capacity) 686 7. Determine appropriate diameter and S-S length Diameter (in) Leff (gas) Lss (gas) Leff (liquid) Lss (liquid) Lss (ft) L/D

24 0.01 2.01 1.19 1.59 3 1.25

30 0.01 2.51 0.76 1.02 3 1.20

36 0.01 3.01 0.53 0.71 4 1.17

Gas Viscosity m Oil Viscosity ml H2O Viscosity mw

in

ow

0.012 1.17 0.69

cp cp cp

4 2.02

5 2.02

6 2.02

1.39

1.39

1.39

22.81

22.80

22.80

2.02

2.02

2.02

in

42 0.01 3.51 0.39 0.52 4 1.14

48 0.01 4.01 0.30 0.40 5 1.13

54 0.01 4.51 0.24 0.31 5 1.11