Transcript PETE 310 Lecutre 17 - Properties of Black Oils

PETE 310
Lecture # 17
Chapter 10 – Properties of Black
Oils - Reservoir Fluid Studies
Fluid Properties for Reservoir
Engineering Processes
The fluid properties of interest to the
Reservoir Engineer are those that affect
the mobility of fluids within the
reservoirs these are used in material
balance calculations
Properties at surface conditions for
transportation and sales (API, viscosity,
oil quality)
Fluid Properties for Reservoir
Engineering Processes
PVT properties are determined from 5
specific lab procedures
–
–
–
–
–
Flash liberation tests
Differential Liberation Tests
Viscosity Measurements
Separator Tests
Compositional measurements
Fluid Properties Determined
Oil Properties
–
–
–
–
–
Bubble Point Pressure
Bo
Rs
Bt
Co and mo
Gas properties
– z
– Bg and mg
Compositions oil & gas
Oil Sampling Procedures
Bottom hole or subsurface samples
Separator Samples
SAMPLE BEFORE RESERVOIR
PRESSURE DROPS BELOW Pb
1.Flash Vaporization Test
V
2
V
t1
oil
3
V t3 = V b
1
t2
oil
4
5
gas
V
oil
gas
V
t4
t5
oil
oil
Hg
Hg
Hg
Hg
Hg
P 1 >> P
b
P2 > P
b
P3 = P
b
P4 < P
b
P5 <P
4
Temperature of Test = Reservoir Temperature
1.Flash Vaporization Test
Properties determined
– Pb
– Co
Determination of Pb
Determination of Co
2.Differential Separation
Test
Gas off
1
2
3
4
gas
5
gas
gas
oil
oil
Hg
oil
oil
Hg
oil
Hg
Hg
P1 = Pb
P2 < Pb
oil
Hg
P2 < Pb
P2 < P b
P3 < P
2
< Pb
Temperature of Test = Reservoir Temperature
2.Differential Separation
Test
Properties Determined
– Oil formation volume factor at the Bubble
Point pressure Bodb and below the bubble
point pressure Bod
– Solution gas-oil ratio at the Bubble Point
pressure Rsdb and below the bubble point
pressure Rsd
– Isothermal compressibility (derived property)
3. Separator Tests
Tests performed at a combination
of different Temperature and
Pressure pairs
3. Separator Tests
Goals: Maximize API, minimize BoSb
& RsSb
Optimization of Separator 2
Conditions
3300
2.86
Solution Gas Oil Ratio at Pb (Rsb)
3280
2.84
3260
2.82
3240
2.80
3220
3200
2.78
3180
3160
50
o
T
= 75 F 2.76
Sep2
100
150
200
Separator 2 Pressure (psia)
250
300
Formation Volume Factor at Pb (Bob)
High Pressure Separator @ 900 psia and 100 ºF
Comparison between 1 & 2
Separators Stages (volatile oil)
2.96
3440
One Separator Stage
3420
2.94
3400
2.92
3380
3360
Low Pressure Separator @ 300 psia and 75ºF
o
T
= 160 F
Sep1
400
500
600
700
800
Separator 1 Pressure (psia)
2.90
900
1000
Formation Volume Factor at Pb (Bob)
Solution Gas Oil Ratio at Pb (Rsb)
3460
Typical PVT Properties for a
Black Oil and a Volatile Oil
3.2
3.0
Formation Volume Factor (Bo)
o
T =180 F
R
Black Oil
Volatile Oil
Black Oil Correlation
2.8
2.6
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
P
b
P
b
0
1000
2000
3000
Pressure (psia)
4000
5000
Typical PVT Properties for a
Black Oil and a Volatile Oil
4000
o
T =180 F
R
Solution Gas Oil Ratio (Rs)
Black Oil
Volatile Oil
Black Oil Correlation
3000
2000
1000
0
P
b
0
1000
2000
3000
Pressure (psia)
P
b
4000
5000
Nomenclature
4. Compositional Tests
http://www.rpi.edu/dept/chem-eng/Biotech-Environ/CHROMO/chromintro.html
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