Ref.1: Ikoku, Natural Gas Production Engineering, John Wiley & Sons, 1984, Chapter 7.Ref.2: Menon, Gas Pipeline Hydraulic, Taylor & Francis, 2005, Chapter 3.
1
Single Phase Gas Flow Series Pipeline with Elevation Change
P2
P1
P3
P4
P5
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2
Single Phase Gas Flow Series Pipeline with Elevation Change
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3
Single Phase Gas Flow Series Pipeline with Elevation Change
1
111
2
2221
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33312
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444123
4321
51
52
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542
52
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4
Single Phase Gas Flow Series Pipeline with Elevation Change
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11
1,,1,1: 1 mmb
av
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Assumeb
ii
Series
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d
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Series
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e eSLdd
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1
1
1 ,:1
5
51
5
Single Phase Gas Flow Series Pipeline with Elevation Change
Series
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13/16
3/161
1
1:
)(032.0: 3/1 Weymouthd
fAssumei
mi
6
Single Phase Gas Flow Parallel Pipeline with Elevation Change
P1 P2
LeA , dA , qA
LeB , dB , qB
LeC , dC , qC
5.05
5.05
5.05
5.05
ParallelbCCBBAA em
b
em
C
em
B
em
A
CBAtotal
LfdK
Lfd
Lfd
LfdK
qqqq
5.02
22
1
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21 )(94.198:,)(94.198
avavg
S
ememavavg
S
g TzPePEKWhere
LfdK
LfTzdPePEq
sc
7
Single Phase Gas Flow Parallel Pipeline with Elevation Change
25.05
5
25.05
5.05
5.05
5
C
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em
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em
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e
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b
Parallel
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fd
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fd
L
23/83/8
1
,:
A
C
A
B
ee
eeeAb
dd
dd
LL
equationWeymouthandLLLddAssume
A
Parallel
CBA
8
Single Phase Gas Flow Looped Pipeline with Elevation Change
P2P1
LeA , dA , qA
LeB , dB , qB
LeC , dC , qCPx
C
AA
LoopSeries
A
Parallel eS
A
B
eee
A
B
ee Le
dd
LLL
dd
LL
23/823/8
11
equationWeymouthandddLLAssume CAee BA,,:
5.02
22
1
5.03/16
5.03/162
22
1 )(1.1112:,)(1.1112
avavg
S
e
A
eavavg
AS
g TzPePEKWhere
LdK
LTzdPePEq
LoopLoop
sc 9
Single Phase Gas Flow Looped Pipeline For Increasing Capacity
P2P1
LeA , dA , qA
LeB , dB , qB
LeC , dC , qCPx
5.03/16
5.03/16
,:
LoopC
A
A e
Anew
eS
e
Aold L
dKqLeL
dKqPipelineOld
equationWeymouthandddLLAssume CAee BA,,:
C
AA
C
A
A
C
A
A
Loop
eS
A
B
e
eS
e
eS
e
A
e
A
old
new
Le
dd
LLeL
LeLd
Ld
23/8
3/16
3/16
2
110
Single Phase Gas Flow Looped Pipeline For Increasing Capacity
P2P1
LeA , dA , qA
LeB , dB , qB
LeC , dC , qCPx
C
A
A
C
A
e
C
A
A
A
ee
Se
eS
fe
Se
ef LeL
Lex
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xAssume
1:
23/8
2
23/8
2
1
11
1
1
1
1
A
B
new
old
f
f
A
B
fold
new
dd
xx
dd
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e
e
e
11
Single Phase Gas Flow Optimum Diameter of Looped Pipeline
P2P1
LeA , dA , qA
LeB , dB , qB
LeC , dC , qCPx
23/8
5.12
1
111)(:
A
B
B
new
oldCAbaseB
dd
dqqLLCCpipelinehorizontalFor
)( :cost Installed 5.15.1CAfBbaseBBBbaseB LLxdCCLdCC
Assume that the cost of a pipe with one inch diameter and one foot length is Cbase
y)graphicall problem thisSolve(0dd:
B
BB d
CdForOptimum
Single Phase Gas Flow Example 1: Description
P2
P1
P3
P4
P5
For the above pipeline, calculate the exit pressure of each segments (P2, P3, P4, P5) based on Weymouth equation and Hysys software.
Feed specifications: T1=50 oF, P1=1000 psia, qsc=200 MMscfd, C1=90%, C2=10% (mole)
Pipeline specifications:L1=20 km, ΔZ1=2000 m, L2=30 km, ΔZ2=-500, L3=15 km, ΔZ3=600, L4=50 km, ΔZ4=-800, d1= d2= d3= d4= 20 in, T5=35 oF, E=0.95(in Weymouth) 13
Single Phase Gas Flow Example 1: Solution
602.045.17,5.502Air
ggiig
oav M
MMyMRT
psiaPPPPPpsiaPAssume av 7.816
32600 2
52
1
35
31
5
85.0211.1,414.15.355,3.674 avprpro
pcpc zPTRTpsiaP
1387.0,1041.0,0867.0,3468.00375.0
4321
1
SSSTz
ZS
avav
g
psiaPLd
TzEqPeP
fteLeLeLLLS
Series
sc
Series
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SSSe
SSe
Seee
)655(612)/(100864.8
499488,2255.0
53/161
272
12
5
321
4
21
3
1
21
Hysys
Single Phase Gas Flow Example 1: Solution
psiaPLd
TzEqPeP
fteLeLLLS
Series
sc
Series
eavavggS
SSe
Seee
)711(700)/(100864.8
279072,3642.0
43/161
272
12
4
21
3
1
21
psiaPLd
TzEqPeP
fteLLLS
Series
sc
Series
eavavggS
Seee
)782(773)/(100864.8
211803,3642.0
33/161
272
12
3
1
21
psiaPLd
TzEqPeP e
avavggS sc )800(805)/(100864.8
23/161
272
12
2 1
1
Hysys
Hysys
Hysys
15
Single Phase Gas Flow Example 2: Description
P2P1
LA , dA
LB , dB
LC , dC Px
An old pipeline has the following specification:
Feed specifications: T1=50 oC, P1=1000 psia, qold =1500 MMscfd, C1=90%, C2=10% (mole)
Pipeline specifications:LA+LC =100 km, ΔZ=0, dA= dC= 42 in, T2=42 oC, E=0.95(in Weymouth)
a)Calculate the outlet pressure (P2)
b)The pipeline capacity is increased by 25% (qnew=1875 MMscfd). Calculate the optimum length and diameter of the looped pipeline.
Single Phase Gas Flow Example 2: Solution
602.045.17,575Air
ggiig
oav M
MMyMRT
psiaPPPPPpsiaPAssume av 876
32740 2
22
1
32
31
2
905.030.1,62.15.355,3.674 avprpro
pcpc zPTRTpsiaP
)738(738)/(100864.8
,328084
23/16
272
12
2 psiaPLd
TzEqPP
ftL
A
avavoldg
Single Phase Gas Flow Example 2: Solution
)( :cost Installed 5.15.1CAfBbaseBBBbaseB LLxdCCLdCC
)3.68(1.69691.0 kmkmLx Bf