research on asphaltene deposition during the process of co 2 flooding huang lei 1 shen pingping 1...
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Research on Asphaltene Deposition During the Process of CO2 Flooding
Huang Lei1 Shen Pingping1 Jia Ying2 Li Shi1
1.State Key Laboratory of EOR (Research institute of Petroleum Exploration and Development,Petrochina) 2.Exploration and Production R
esearch Institute, Sinopec
For IEA EOR MeetingCNPC
1 、 Research Background
2 、 Asphaltene Precipitation Experiment study for CO2 Injecti
on
3 、 Asphaltene Precipitation Model for CO2 Injection Process
4 、 Compositional simulator Considering Asphaltene Deposit
ion
5 、 Conclusion
contentCNPC
Asphaltene deposition in the well hole
Asphaltene deposition in the pipe line
Research BackgroundCNPC
Asphaltene Precipitation:
Asphaltene component to be s
eperated from oil and get togeth
er to form another phase differen
t from oil phase
Asphaltene deposition:
the process of precipitated as
phaltene settling onto the surfac
e of porous media
Two Basic Concept
AsphalteneResinsaromatic
sAlkanesCO2
CO2 Injection
Asphaltene Precipitation
Asphaltene Deposition
Research BackgroundCNPC
1 、 Research Background
2 、 Asphaltene Precipitation Experiment study for CO2 Injecti
on
3 、 Asphaltene Precipitation Model for CO2 Injection Process
4 、 Compositional simulator Considering Asphaltene Deposit
ion
5 、 Conclusion
contentCNPC
The Basic Properties and Composition of Experiment OilSampling
Separator Sampling
Reservoir Pressure ( MPa ) 32
Reservoir Temperatue(℃) 110
Bubble Point ( MPa ) 4
DOR ( m3/m3 ) 12.9
FVF 1.088
Density@Pr,Tr (g/cm3) 0.8219
Viscosity@Pr,Tr(mPa.s) 7.02
Dead Oil Density (g/cm3) 0.886
CO2 0.34
C1+N2 11.26
C2 ~ C10 23.43
C11+ 64.97
Wax of Dead oil ( % ) 24.69
Asphaltene of Dead oil ( % ) 16.79
Evaluation Representative
Asphaltene Precipitation Experiment study for CO2 InjectionCNPC
1
2 3
45
6
7
8
9
10
注:1.恒速驱替泵;2.地层油容器;3. CO2气容器;4.恒温箱;5.激光检测系统;
6.样品筒活塞;7.样品;8.激光发射器;9.激光接收器;10.电磁搅拌系统。
Equipment for Precipitation Onset Point Measure
Asphaltene Precipitation Experiment study for CO2 InjectionCNPC
Equipment for Precipitate quantity measure
13
11
12
1514
4 6
CBA
P3
P5 Õæ
P4
31
600 ml 1000ml
CO2
1000ml
N2
Æø
Ñù
Æ¿
Ôö
ѹ
»ú
È¡Ñùϵͳ
CO2
P1
D
E
5
P2
2
16
9
107
8
注: 1-3. 手动高压泵 4-16. 高压阀门 P1-P5. 压力表A. 主平衡釜 B. 副釜 C. 转样釜 D. 空气恒温浴 E. 石油醚洗瓶
Asphaltene Precipitation Experiment study for CO2 InjectionCNPC
4. 0E- 12
4. 2E- 12
4. 4E- 12
4. 6E- 12
4. 8E- 12
5. 0E- 12
5. 2E- 12
5. 4E- 12
0. 0 0. 1 0. 2 0. 3 0. 4 0. 5 0. 6 0. 7CO注入 2在原油中的摩尔分数
PT
L ,
w
出现气相
onset
20.0MPa4. 4E- 12
4. 6E- 12
4. 8E- 12
5. 0E- 12
5. 2E- 12
5. 4E- 12
5. 6E- 12
5. 8E- 12
0. 0 0. 1 0. 2 0. 3 0. 4 0. 5 0. 6 0. 7CO注入 2在原油中的摩尔分数
PT
L ,
w
出现气相
onset
26.0MPa4. 4E- 12
4. 6E- 12
4. 8E- 12
5. 0E- 12
5. 2E- 12
5. 4E- 12
5. 6E- 12
5. 8E- 12
0. 0 0. 1 0. 2 0. 3 0. 4 0. 5 0. 6 0. 7CO注入 2在原油中的摩尔分数
PT
L ,
w
出现气相
onset
20.0MPa 23.0MPa 26.0MPa
4. 4E- 12
4. 6E- 12
4. 8E- 12
5. 0E- 12
5. 2E- 12
5. 4E- 12
5. 6E- 12
5. 8E- 12
0. 0 0. 1 0. 2 0. 3 0. 4 0. 5 0. 6 0. 7 0. 8CO注入 2在原油中的摩尔分数
PT
L ,
w
出现气相
onset
29.0MPa5. 4E- 12
5. 6E- 12
5. 8E- 12
6. 0E- 12
6. 2E- 12
6. 4E- 12
6. 6E- 12
0. 0 0. 1 0. 2 0. 3 0. 4 0. 5 0. 6 0. 7 0. 8CO注入 2在原油中的摩尔分数
PT
L ,
w
出现气相
onset
32.0MPa5. 2E- 12
5. 4E- 12
5. 6E- 12
5. 8E- 12
6. 0E- 12
6. 2E- 12
6. 4E- 12
0. 0 0. 1 0. 2 0. 3 0. 4 0. 5 0. 6 0. 7 0. 8CO注入 2在原油中的摩尔分数
PT
L ,
w出现气相
onset
35.0MPa
29.0MPa 35.0MPa32.0MPa
CNPC
PLT response of asphaltene Precipitation process
Asphaltene Precipitation Experiment study for CO2 Injection
injection pressure
MPa
CO2
content@onset
mol%
CO2 content
@vapering
mol%
Asphaltene in oil wt%
Asphaltene Precipitation
wt%
noCO2 16.79 0
23.00 0.27 0.60 11.32 5.47
26.00 0.30 0.64 10.31 6.48
29.00 0.33 0.68 9.85 6.94
32.00 0.36 0.71 9.52 7.27
35.00 0.39 0.73 9.13 7.66
Result of Asphaltene Precipitation Experiment
0
10
20
30
40
50
60
70
0 0. 2 0. 4 0. 6 0. 8 1
CO2 , mol %摩尔分数
MPa
压力,
临界点
沥青质沉淀初始点实验值
饱和压力实验值
饱和压力线
沥青质沉淀初始线
Onset line
saturation line
Critical point
CNPC
Asphaltene Precipitation Experiment study for CO2 Injection
1 、 Research Background
2 、 Asphaltene Precipitation Experiment study for CO2 Injec
tion
3 、 Asphaltene Precipitation Model for CO2 Injection Proce
ss
4 、 Compositional simulator Considering Asphaltene Depo
sition and its Application
5 、 Conclusion
contentCNPC
Presumption
Because precipitated asphaltene is composed of heavy polarity an
d non-ideality molecules, which is solid-like precipitated liquid with
strong viscosity under reservoir condition. Thus, equation of state i
ncorporating association ( AEOS ) is used to describe the phas
e behavior of asphaltene
Ignoring resin component , Precipitated Asphaltene is composed
of asphaltene component
asphaltene component do not behave association in oil phase
During the process of asphaltene precipitation, no crystal formed
Asphaltene Precipitation Model for CO2 Injection ProcessCNPC
Because precipitated asphaltene is composed of heavy polarity
and non-ideality molecules, the compress factor of association
compound established by Anderko is introduced to describe the
non-ideality of precipitated asphaltene
where1 phch ZZZ
2
1 1 4 /ch
aa
ZRTK V
Compressible factor of Asphaltene
Asphaltene Precipitation Model for CO2 Injection ProcessCNPC
1 2
ln ( 1) ln( 1) ln2 2 1 2
ph
ch ph ch ph
ph
Z BAZ Z Z Z
B Z B
1 2ln ( , , , ) ( , , )ch chZ V T B Z V T
Fugacity Calculation for Asphaltene Phase
Asphaltene Precipitation Model for CO2 Injection ProcessCNPC
where
0 1Vn
0 1Sn
0 1S Vn n
1
1
10
1 1
1
1 1
VLNi i
S VL Vi i
SN
LS S VL VN N
K z
n K n
z n
K n K n
Vapor/liquid/Asphaltene equilibrium model:
Asphaltene Precipitation Model for CO2 Injection ProcessCNPC
Judgement of asphaltene precipitation is as follows:
if , asphaltene would precipitate ;
if , asphaltene would not precipitate ;
if , asphaltene begin to precipitate 。
Where is content of heavy components in oil.
ln lnNo sf f
ln lnNo sf f
ln lnNo sf f
Nof
Phase stability analysis of precipitated asphaltene:
Asphaltene Precipitation Model for CO2 Injection ProcessCNPC
Regression Result for Asphaltene Pricipitation onset point
Asphaltene Precipitation Model for CO2 Injection Process
0
20
40
60
80
100
120
0 0. 1 0. 2 0. 3 0. 4 0. 5 0. 6 0. 7 0. 8 0. 9 1
CO2 , %摩尔百分含量
MPa
压力,
计算饱和压力线
临界点
沥青质沉淀初始点计算值
沥青质沉淀消失点计算值
沥青质沉淀初始点实验值
饱和压力实验值
CO2,mole%
cal.Pb point
cal.onset line
cal.disappearance line
expl.onset line
exp.Pb line
critical point
CNPC
When injection pressure is constant, precipitated asphaltene increases with the increase of injected C
O2 before CO2-oil system reaches saturation. Precipitated asphaltene reaches maximum at saturation
state, and then precipitated asphaltene decreases with the increase of injected CO2
When the CO2 mole percents of CO2-oil system are constant, precipitated asphaltene reaches maxi
mum at saturation pressure.
The higher system pressure, the more maximum quantities of precipitated asphaltene
Asphaltene Precipitation Model for CO2 Injection Process
0. 0
1. 0
2. 0
3. 0
4. 0
5. 0
6. 0
7. 0
8. 0
9. 0
20 30 40 50 60 70 80 90
CO2 %摩尔百分数,
wt沥青质沉淀量,
%
23MPa 31MPa
26MPa 29MPa
35MPa 37MPa
0
1
2
3
4
5
6
7
8
0 10 20 30 40 50 60压力,MPa
沥青质沉淀量,
wt%
0
10
20
30
40
50
60
70
气相摩尔百分数,%
0. 6CO2沥青质沉淀量0. 64CO2沥青质沉淀量
0. 68CO2沥青质沉淀量0. 71CO2沥青质沉淀量0. 73CO2沥青质沉淀量0. 6CO2气相摩尔分数
0. 64CO2气相摩尔分数0. 68CO2气相摩尔分数0. 71CO2气相摩尔分数
0. 73CO2气相摩尔分数
the relationship between asphaltene precipitation and CO2 mole percent at fixed pressure
the relationship between asphaltene precipitation, gas phase mole percent and pressure at varied CO2 mole percent
Asp
ha
lten
e P
recip
itatio
n,w
t%
Ga
s mo
le%
Asp
ha
lten
e P
recip
itatio
n,w
t%
CO2,mole% pressure,MPa
CNPC
1 、 Research Background
2 、 Asphaltene Precipitation Experiment study for CO2 Inject
ion
3 、 Asphaltene Precipitation Model for CO2 Injection Proces
s
4 、 Compositional simulator Considering Asphaltene Depos
ition
5 、 Conclusion
contentCNPC
0 ,
,c
isfsf o c
i ny
N N i n
1
0fn
w wrww w wk
kw
Skkq
t
where ,
Conservation Equation for Component i
1
( ) 0f
j ij jnjrj
j ij isf j i ik ijj k jj
y Skk
y y q yt
0
o g srgroo o g g t
o g
N N Nkkkkq
t
Compositional simulator Considering Asphaltene Deposition
Conservation Equation for Water
Conservation Equation for Oil and Gas
CNPC
Precipitated Asphaltnene is made of three parts : deposit onto the p
orous media surface through adsorption ; deposit through mecha
nical entrapment ; suspended in the oil phase
adoption by unit rock volume
surface adsorption by unit rock mass follows a Langmuir isotherm :
saN
sfN
s sa se sfN N N N
s
saRsa
~1
M
WN
=
,max
1sa a sf
saa sf
W K CW
K C
oo
ssf6
sf
10
MN
MNC =
mechanical entrapment : 0sf
ses
ˆ m
CN
v
=
seN
suspended content in oil phase :
CNPC
Compositional simulator Considering Asphaltene Deposition
Plugging Equations
0 0 0
ˆ 11 1 exp 1 1
exp -1
K E KE G
K G K
=
ssesaˆ uNN +-=
Using following equations established by Cernansky
&Siroky ( 1985 ) to describe plugging process
CNPC
Compositional simulator Considering Asphaltene Deposition
Sequnia
l
Core length(c
m)
Perm
( mD )
Soi( % ) Pex(MPa)
dp(MPa)
Injection
PV
Exp. Re
(%)
New method
Cal. Re
(%)
Conventional methed
Cal. Re
(%)
1 43.16 8.92 0.5494 19 5 3.31 59.76 58.47 63.28
2 42.85 8.91 0.5527 24 6.4 3.11 64.38 64.12 67.85
3 45.82 8.69 0.5561 29 8 3.11 78.07 80.13 82.77
4 43.16 8.92 0.5524 34 10 2.88 79.24 82.04 84.32
2m
Recovery factor matching for core flooding
CNPC
Compositional simulator Considering Asphaltene Deposition
Asphaltene deposition front is consistent with gas front, which indicate
s that CO2 injection lead to asphaltene pricipitate
0
0. 1
0. 2
0. 3
0. 4
0. 5
0. 6
0. 7
0. 8
0. 9
0 2 4 6 8 10 12 14 16 18 20网格块
g沉积沥青质质量,
0
10
20
30
40
50
60
%饱和度,
沥青质沉积量
气体饱和度
0
0. 1
0. 2
0. 3
0. 4
0. 5
0. 6
0. 7
0. 8
0. 9
0 2 4 6 8 10 12 14 16 18 20网格块
g沉积沥青质质量,
0
10
20
30
40
50
60
%饱和度,
沥青质沉积量
气体饱和度
0
0. 1
0. 2
0. 3
0. 4
0. 5
0. 6
0. 7
0. 8
0. 9
0 2 4 6 8 10 12 14 16 18 20网格块
g沉积沥青质质量,
0
10
20
30
40
50
60
%饱和度。
沥青质沉积量
气体饱和度
0
0. 1
0. 2
0. 3
0. 4
0. 5
0. 6
0. 7
0. 8
0. 9
0 2 4 6 8 10 12 14 16 18 20网格块
kg沉积沥青质质量,
0
10
20
30
40
50
60
70
%饱和度,
沥青质沉积量
气体饱和度
0.1HCPV0.2HCPV
0.3HCPV 0.4HCPV
CNPC
Compositional simulator Considering Asphaltene Deposition
0
5
10
15
20
0 0. 2 0. 4 0. 6 0. 8 1 1. 2 1. 4 1. 6
PV, d
,g沉积沥青质质量
25MPa
29. 4MPa35MPa
As pressure rises , more asphaltene deposition lefted in core.
CNPC
Compositional simulator Considering Asphaltene Deposition
1 、 Research Background
2 、 Asphaltene Precipitation Experiment study for CO2 Injec
tion
3 、 Asphaltene Precipitation Model for CO2 Injection Proces
s
4 、 Compositional simulator Considering Asphaltene Depo
sition
5 、 Conclusion
contentCNPC
AEOS can describe Asphaltene Precipitation behavior.
For a fixed pressure system, precipitated asphaltene increases
with the increase of injected CO2 before system reaches satura
tion, then precipitated asphaltene decreases with the increase.
When system composition is fixed, precipitated asphaltene rea
ch its climax near saturation pressure.
Asphaltene Precipitation should be considered in CO2 injection
process of high Asphaltene content oil.
Asphaltene deposition front is consistent with CO2 front.
As pressure rises , more asphaltene deposition lefted in core.
ConclusionCNPC