viscosifying surfactants for chemical...
TRANSCRIPT
Viscosifying Surfactants for Chemical EOR
M. Morvan , G. Degré (Rhodia)J. Bouillot & A. Zaitoun (Poweltec)R.S. Al-Maamari & A.R. Al-Hashmi (SQU) H.H. Al-Sharji (PDO)
32nd Annual IEA EOR Symposium & Workshop
• Introduction
• Integrated workflow
•Technology positioning
• Field case
• Conclusion
2
Contents
Investigate surfactant formulations providing reserve increase
Surfactants(Displacement efficiency)
Surfactants(Displacement efficiency)
Polymers(Sweep efficiency)
Polymers(Sweep efficiency)
Time
~30%
Ultimate recovery
Time
~50%
Higher final recovery Faster recovery
Water floodSurfactant flood
Water floodPolymer flood
~30%
Ultimate recovery
3
Background in Chemical EOR
Simulation (H. Bodiguel, LOF)
M= 0,01 M= 100
Fingering Homogeneous front
Water + Surfacant
rP
γ2=∆
100 µµµµm
Trapped oil
Micromodel at LOF
• Rheological properties of micellar structures in aque ous solutions
Spherical Micelles Cylindrical Micelles
Low viscosityNewtonian fluid
Entanglements(analogy with polymer)
Typical EOR surfactant formulations
L ≈≈≈≈ 1 µµµµm
Viscosifying surfactant as an alternative approach to polymer & surfactant polymer flooding
Breakage/recombination dynamic
..)5.21()( +Φ+=Φ sηηΦ Φ Φ Φ = volume fraction
τη0
0 G≈G0: Elastic modulusττττ: Relaxation time
Introduction to viscosifying surfactants for EOR
+
• Introduction
• Integrated workflow
•Technology positioning
• Field case
• Conclusion
5
Contents
An integrated workflow
High Throughput Screening (HTS) tools have been developed to demonstrate surfactant solubility in reservoir conditions (brine, temperature). Classical ageing tests have been implemented to investigate thermal stability.
Millifluidic set-up have been designed to investigate fluid propagation in porous media in comparison with bulk flow properties & measure surfactant retention.
Petrophysic experiments are used to measure increase in oil recovery and surfactant adsorption in cores
Lab-scale simulations are required before up-scaling and injection strategy definition – Physics from SARIPCH
implemented to full field simulators
Coreflood Validation
Simulation
A whole set of capabilities are required for techno logy positioning
Surfactant solubility & stability
Flow properties
• Robotic platform used to determine surfactant solub ility versus salt & temperature
High Throughput method for solubility measurement
• Robotic microplates filled with surfactant solutions• Light transmission measurements with grey scale for solubility
screening: surfactant and salt concentrations, temp erature
Salt
Salt
Salt
Salt conc
conc
conc
conc.. ..
SolubleSolubleSolubleSoluble InsolubleInsolubleInsolubleInsoluble
Surfactant concentrationSurfactant concentrationSurfactant concentrationSurfactant concentration
Principle of miniaturized core flood test developed at Rhodia LOF
Syringe pump
Porous mediaInjectivity, porous media
∆Pcore∆Pcapillary
Imposed flow rate
CapillaryAdsorption
Syringe pump
Porous mediaInjectivity, porous media
∆Pcore∆Pcapillary
Imposed flow rate
CapillaryAdsorption
5 cm
Syringe pumpCapillaryviscometer
Pressure sensor
Pressure sensorcore
• A millifluidic device has been developed by Rhodia t o measure fluid propagation and adsorption in porous media
This miniaturized test is used prior to full corefl ood study to pre-screen performances of surfactant formulations
Flow properties of viscosifying surfactants
• Bulk rheology is measured using stress controlled rh eometer
• Introduction
• Integrated workflow
•Technology positioning
• Field case
• Conclusion
9
Contents
Viscosity measurements
Our viscosifying surfactants are salt tolerant (including divalent ions) with
favorable impact of high brine concentration
10
Salinity (g/L TDS)
T (°C)
0
51°C
200
85°C
966
Field 2
Field 1
Field 3
Shear rate: 4 s-1
• Viscosity performances have been evaluated in various conditions of salinity (6 to 200 g/L) and temperature (51°C to 85°C )
• Viscosity of tens of cP is measured for concentration between 0.1%w/w and 0.5%w/w
0 0.1 0.2 0.3 0.4 0.50
20
40
60
80
concentration (%w/w
)
Abs
. vis
cosi
ty(c
P)
0 0.1 0.2 0.3 0.4 0.50
20
40
60
80
concentration (%w/w
)
Abs
. vis
cosi
ty(c
P)
0.1 0.3 0.5 0.7 0.90
50
100
150
200
concentration (%w/w)
Abs
. vis
cosi
ty(c
P)
0.1 0.3 0.5 0.7 0.90
50
100
150
200
concentration (%w/w)
Abs
. vis
cosi
ty(c
P)
0.1 0.3 0.5 0.7 0.90
100
200
300
400
500
concentration (%w/w)
Abs
. vis
cosi
ty(c
P)
0.1 0.3 0.5 0.7 0.90
100
200
300
400
500
concentration (%w/w)
Abs
. vis
cosi
ty(c
P)
• Favorable impact of salinity on viscosity is observed
96 2000
20
40
60
80
salinity (g/L TDS)
rela
tive
vis
cosi
ty
T = 85°C
C = 0.3%w/w
Thermal stability• Anaerobic ageing tests are performed to evaluate thermal stability of the viscosifying surfactants.
• Ageing of two surfactant systems at two temperatures (51°C and 90°C) and various salinities (6, 32 and 97 g/L) are performed with oxygen content less tha n 50 ppb.
• Stability is evaluated by measuring viscosity as a function of time .
0 50 100 1500
0.2
0.4
0.6
0.8
1
1.2
time (days)
η /η 0
surf. A - TDS = 6 g/L
surf. B - TDS = 6 g/L
surf. A - TDS = 97 g/L
surf. B - TDS = 97 g/L
0 50 1000
0.2
0.4
0.6
0.8
1
1.2
time (days)
η /η 0
surf. A - TDS = 32 g/L
surf. A - TDS = 96g/L
surf. B - TDS = 96g/L
T = 51°C[02] < 10 ppb T = 90°C
[02] < 50 ppb
No degradation is observed over 4 months at T = 51°C and T = 90°C
Glove box test Sealed ampoules
• Example of flow behavior in representative porous m edia (Clashachsandstone) using miniaturized core flood test desig n by Rhodia
Rheometer ���� Bulk viscosity
Viscosity in porous media ���� injection in coresimpose Q and measure ∆∆∆∆P
100
102
104
100
101
cisaillement (s-1)
visc
osi
te, R
m C2
C1
Miniaturized core dataBulk rheology
Flow in porous media matches bulk rheologyGood propagation of viscosifying surfactant in porou s media
Fluid propagation in synthetic cores
Φ= k
r8
Mean pore radius
Sr
Q=γ&
Darcy’s Law
Flow rate
Q
Shear rate
Pressure drop viscosity
∆PWater
Surf
Water
Surfm
P
PR
ηη .. =
∆∆
=
Capillary bundle model
• Viscosifying surfactant flood versus polymer flood• Claschach core: ΦΦΦΦ = 0.18 - k = 1.1 Da – Temperature: 50°C • Fluid formulation in sea water - Oil viscosity: 4.2 cp at 50°C
Coreflood tests
0 2 40
20
40
60
80
100
120
time
Sa
tura
tion
(%
)
Sw=1 Swi Sor
Noadditional
oil
HPAM (C= 0.3 g/L, ηηηη = 1.7 cP)
Viscosifying surfactant (C = 3 g/L, k=1.1 D, ηηηη = 1.7 cP)
∆∆∆∆Sor = 13% OOIP
0 2 40
20
40
60
80
100
120
time
Sa
tura
tion
(%
)
water oil water polymer
Sw=1 Swi Sor
water oil water surfactant
Additional oil
100 80
20
5248
5248 100 85
15
5743
6832
• Introduction
• Integrated workflow
•Technology positioning
• Field case
• Conclusion
14
Contents
Viscosifying surfactant: field case
Reservoir conditions•Temperature: T = 51°C
• Permeability: k ~ 1 – 5 D (Sandstone)
• Crude oil viscosity at 51°C : ηηηη = 530 cP
• Brine concentration: 6.2 g/L TDS
Methodology•Select best viscosifying surfactant that matches reservoir characteristics:
- Viscosity
- Adsorption
- Injectivity
• Evaluate performance in reservoir conditions
- Adsorption
- Oil recovery efficiency
10-2
10-1
100
101
102
100
101
102
103
shear rate (s-1
)
ab
solu
te v
isco
sity
(cP
)Chemistry selection: viscosity performance
0.5%w/w
10-2
10-1
100
101
102
103
100
101
102
103
shear rate (s-1
)a
bso
lute
vis
cosi
ty (
cP)
0.4%w/w
0.3%w/w
0.2%w/w
0.1%w/w
HPAM 0.09%w/wHPAM 0.09%w/w
1%w/w
0.8%w/w
0.6%w/w
0.4%w/w
0.2%w/w
Surfactant A Surfactant B
18 cP0.4%w/wSurf. B
22 cP0.3%w/wSurf. A
20 cP0.09%w/wHPAM
Vicosity (7s -1)ConcentrationSolution
• Adsorption is measured using mini Clashach cores (L ~ 5 cm, d = 1.3 cm, k ~ 1 -2 D).
• Adsorption is determined by measuring delay of surf actant front. Capillary rheometer is used to detect the surfactant front at the outle t of the core.
0 2 4 6 8 10 12 140
20
40
60
80
100
120
V
∆ P
core
pc
m
CVVAds 0).( −
=
∆Pbrine
∆Psurf
C = 0
C = C0
Vc
Outlet surfactant front
Co: Sufactant concentrationmcore : Mass of the core
∆P∆P
Syringe pump
Porous media
Injectivity
corecapillary
Capillary
Adsorption
Imposedflow rate
Adsorption test
Chemistry selection: reduced adsorption
• Chemistry, process and formulation routes have been studied to reduce surfactant adsorption with no impact on viscosity p erformance
0 2 4 60
500
1000
1500
2000
2500
Ad
sorp
tion
(µ
g/g
)Adsorption measurements in monophasic
conditions using mini-core test
Surf. A
Surf. B
Proc. A
Proc. B
Proc. A
Proc. B
Proc. B + additive
Selected chemical
Viscosifying surfactant: oil recovery efficiency
Surfactant (kw = 2D, C = 0.4%w/w)
0 2 40
20
40
60
80
100
120
time
satu
ratio
n (
%)
∆∆∆∆Sor
=
20% OOIP
Sw=1 Swi Sor
water oil water surfactant
Adsorption = 500 µg/g
100
8614
6238
7921
Sor reduction with viscosifying surfactant :
20% OOIP
Sor reduction with viscosifying surfactant :
20% OOIP
Standard injection protocol
• Introduction
• Integrated workflow
•Technology positioning
• Field case
• Conclusion
20
Contents
Conclusion• Following performances have been measured for this patented technology in different conditions
• Viscosity at low concentration: 0.1 to 0.5%w/w
• Sor reduction in coreflood ∆Sw = 10 to 20% OOIP (ηoil up to 500 cPs)
• High temperature / high salinity tolerance
• Shear thinning / recombination dynamics (Unlike Polymer)
• Limited surface facility required
• Perspectives
• Pursue experiment on field case reservoir:
- Optimization of injection strategy
- Simulation and extrapolation at pilot scale to evaluate economics
• Explore more severe conditions (low permeability, high temperature...)