Production System Selection
For
High-Pour Point Crude Producing Well
ZoltánTurzó, PhD.
University of Miskolci
Low and volatile oil price environment. Technical
responses in the Pannonian basin
SPE HUN Workshop
Garden Hotel, Szolnok, 17/11/2016
Well Data
Perforations: 1850-1900 m
Bottom: 2000 m
9 5/8" casing shoe Cement on surface
2 7/8" OD tubingPacker 1800 m
13 3/8" casing shoeCement on surface
7" casing shoe Cement on surface
0
50
100
150
200
250
0 10 20 30 40 50
FBH
P, b
ar
Flow Rate of Oil, Sm3/d
AOFP : 46.8 Sm3/d
PI : 0.24 Sm3/(bar d)Tr : 110 oC
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
30 40 50 60 70 80 90
Dyn
amic
Vis
cosi
ty, P
a s
Temperature, oC
Properties of Dead Oil
Density:
20 : 885 kg/m3
: 0.870 kg/(m3 oC)
Problems
• High Pour Point Crude
• Limited Reservoir Energy, Small Rates
• Sytem for Production Test(/Production)
Flowing Well
Transient Temperature Distribution by Enthalpy Balance
0
200
400
600
800
1000
1200
1400
1600
1800
2000
0 20 40 60 80 100
De
pth
, m
Temperature, oC
1 m3/d
5 m3/d
10 m3/d
15 m3/d
20 m3/d
25 m3/d
30 m3/d
35 m3/d
40 m3/d
45 m3/d
Pour Point
Production Time : 360 day
Temperature profile stabilized in short time!
Flowing Well
Dynamic Viscosity vs. Depth
0
200
400
600
800
1000
1200
1400
1600
1800
2000
0 500 1000 1500 2000 2500 3000
De
pth
, m
Dynamic Viscosity, mPas
1 m3/d
5 m3/d
10 m3/d
15 m3/d
20 m3/d
25 m3/d
30 m3/d
35 m3/d
40 m3/d
45 m3/d
Pour Point
Production Time : 1 day
Flowing Well, Pressure vs. Depth
No significant difference!
Friction loss is not
significant!
Main task is the fluid lifting
not the friction loss due to
high viscosity!
The chart does not show
the effect of cooling in
production breaks, neither
the paraffin deposition on
pipe wall!
Both are serious problem!
0
200
400
600
800
1000
1200
1400
1600
1800
2000
0 50 100 150 200
De
pth
, m
Pressure, bars
1 m3/d
5 m3/d
10 m3/d
15 m3/d
20 m3/d
25 m3/d
30 m3/d
35 m3/d
40 m3/d
45 m3/d
Production Time : 1 day
Flowing Well, Insulated Tubing
Reduced Deposition on
Pipe Wall!
Cooling Down Remain
Problem in Production
Breaks!
Fluid Lift Required!
0
200
400
600
800
1000
1200
1400
1600
1800
2000
0 20 40 60 80 100
De
pth
, m
Temperature, oC
1 m3/d
5 m3/d
10 m3/d
15 m3/d
20 m3/d
25 m3/d
30 m3/d
35 m3/d
40 m3/d
45 m3/d
Pour Point
Production Time : 1 dayTop 800 m of tubing is insulatedby 4 cm foam, 0.035 W/(m K)
Artificial Lift Required!
• Appropriate for Production Test– Cheap enough for single well
– Easy to install
– Flexible
– Applicable for highy pour point,
heawy oil
– Applicability after production test is
an Advantade
„Steam Lift”?
Required Minimal „gas lift pressure” - 30 bar ~ 220 oC
Examined 305 oC ~ 80 bar
100
150
200
250
300
350
0 20 40 60 80 100 120
Sa
tura
tio
n T
em
pe
ratu
re,
oC
Pressure, bar
Steam Saturation Temperature
Temperature vs. Depth of Steam
Injected into the Annulus
The cooling effect of tubing is neglected!
0
200
400
600
800
1000
1200
1400
1600
1800
2000
0 50 100 150 200 250 300 350
De
pth
, m
Temperature, oC
1 m3/d
2 m3/d
3 m3/d
4 m3/d
5 m3/d
6 m3/d
7 m3/d
8 m3/d
9 m3/d
10 m3/d
Sat. Temp.
Tinj: 305 oCPinj: 80 barSat Temp: 295 oC
Temperature vs. Depth of Steam
Injected into the Annulus
0
200
400
600
800
1000
1200
1400
1600
1800
2000
0 50 100 150 200 250 300 350
De
pth
, m
Temperature, oC
1 m3/d
2 m3/d
3 m3/d
4 m3/d
5 m3/d
6 m3/d
7 m3/d
8 m3/d
9 m3/d
10 m3/d
Sat. Temp.
Tinj: 305 oCPinj: 60 barSat Temp: 275.6 oC
The cooling effect of tubing is neglected!
Temperature Distribution in Tubing
Convective Heat Transfer!
Steam Lift is not Possible in
this case!
Possible:
• Small Injection
Pressure,
• steam mass is
greater than the
produced fluid mass!
Uneconomic!
0
200
400
600
800
1000
1200
1400
1600
1800
2000
0 50 100 150 200 250 300 350
De
pth
, m
Temperature, oC
Fluid Temp.
Sat. Temp
Tinj: 305 oCPinj: 80 barSat Temp: 295 oC
Qo: 15 Sm3/dQw: 5 Sm3/d
Dilutant Injection
To Decrease Viscosity and Pour Point
Constant Effect, Production Break Problems Eliminated
780
790
800
810
820
830
840
850
860
870
880
0
1000
2000
3000
4000
5000
6000
0 5 10 15
De
nsi
ty, k
g/m
3
Vis
cosi
ty, m
Pa
s
Dilutant Injection Rate, Sm3/d
Wellhead Liquid Viscosity
Wellhead Liquid Density
Dilutant Injection
To Decrease Viscosity and Pour Point
Constant Effect, Production Break Problems Eliminated
Must be combined by artificial lift!
0
2
4
6
8
10
12
14
0 2 4 6 8 10 12 14 16
Oil
Pro
du
ctio
n R
ate
, Sm
3/d
Dilutant Injection Rate, Sm3/d
Dilutant Injection
To Decrease Viscosity and Pour Point
Constant Effect, Production Break Problems Eliminated
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
0 20 40 60 80 100
Dyn
amic
Vis
cosi
ty, P
as
Temperature, oC
Effect of Diluting Agent on Oil Viscosity
0% 10%
20% 40%
50% 66%
Jet Pump
The diluting agent can be the power fluid
of the jet pump system.
Diluting agent can be:
heated water, revers flow application
heated well fluid, revers flow application
heated light oil, gasoline , lower temperature;
normal or revers flow application
Jet Pump
Using heated water and heated well fluids
small power fluid requirement, continuous
cleaning and recirculating
Using light oil, or gasoline
continuous power fluid supply is required
Possible power fluid choice could be water
with 5-10 % gasoline, bigger safety in case
of production breaks.
The surface units required for jet pumping
is slightly more complicated than in case of
simple diluting agent injection.
Jet Pump
No moving parts in the downhole pump,
long production life, low repair cost
If free-pump installation is used, the pump
can be circulated to the bottom, to produce,
or can be circulated to the surface for
repair. No need for high cost tubing
operations.
Jet Pump
Reverse flow installation Normal flow installation
Jet Pump
Normal flow installation Normal flow installation
Jet Pump
The best fluid ratio (Produced liquid rate/Power fluid rate):
30 Sm3/day power fluid rate
210 bars surface injection pressure.
Production rate < the required 30 m3/day.
Suggested:
185 bar power fluid surface injection pressure,
60 Sm3/day injection rate.
Conclusions
• In case of low rates the high viscosity does not
cause high friction loss
• Insulation decrease the problems due to
production breaks and deposition
• Fluid lifting is the main problem
• Steam Lift is not an economic solution
• Dilitant ijection Must be combined with artificial
lifting
• Jet Pump is a valuable tool for heavy oil
production
Thank You for Your Attention!
