VISCOELASTIC SURFACTANTS VISCOELASTIC SURFACTANTS FORFOR
OIL RECOVERYOIL RECOVERY
PRIMARY RECOVERY
Produces 2-15% Original Oil in Place
OIL PRODUCTIONSECONDARY RECOVERY
Another 15-20% OOIP may be produced by water flooding
ENHANCED OIL RECOVERY
Another 4-35% OOIP may be produced by EOR
EOR Process•Thermal•Gas miscible•Chemical
EOR Process
•Microbial•Gravity Mining
Approx. 460 billion
bbls OIP before any production
Approx. 65% 300 billion bbls OIP after secondary recovery
4-35%
15-20%
2 -15%
OilOil WaterWater OilOil
PreflushPolymer for mobility control
Surfactant
To reduce IFT
Oil Bank
Water after flush
Injection fluid
Injection pump
Injection well
Oil
Producing well
CHEMICAL EOREOR may include surfactant, polymer and alkaline flooding. After a reservoir is conditioned by a water preflush, specific chemicals are injected to reduce the IFT (help to release oil) and improve mobility control (reduce channeling)
Injection pump
TWO PRIMARY MECHANISMSIN CHEMICAL EOR
Reduce interfacial forces
Improve sweep efficiency & mobility ratio
TWO PRIMARY MECHANISMSIN CHEMICAL EOR
Reduce interfacial forcessurfactants
Improve sweep efficiency & mobility ratio
ROLE OF IFT ROLE OF IFT
SURFACE TENSION & INTERFACIAL SURFACE TENSION & INTERFACIAL TENSIONTENSION
<0.01<0.01O/W with 0.05O/W with 0.05--0.2% EOR 0.2% EOR surfactantsurfactant
33--3030Oil/WaterOil/Water
66--4040OilOil
7272WaterWater
ST or IFT, mN/mST or IFT, mN/mDescriptionDescription
RELATIONSHIP BETWEEN CAPILLARY RELATIONSHIP BETWEEN CAPILLARY NUMBER AND OIL RECOVERYNUMBER AND OIL RECOVERY
Chatzis and Morrow, SPEJ, (1994) 561.Chatzis and Morrow, SPEJ, (1994) 561.
0
20
40
60
80
100
1.E-06 1.E-05 1.E-04 1.E-03 1.E-02
Capillary Number
% O
il R
ecov
ered
Nc = ν µ /σ cosθ
Nc =Nc = Capillary NumberCapillary Number
νν = Darcy Velocity= Darcy Velocity
µµ = Viscosity= Viscosity
σσ= Interfacial Tension= Interfacial Tension
Θ=wetting angle
TWO PRIMARY MECHANISMSIN CHEMICAL EOR
Reduce interfacial forcesSurfactants
Improve sweep efficiency & mobility ratio
TWO PRIMARY MECHANISMSIN CHEMICAL EOR
Reduce interfacial forcesSurfactants
Improve sweep efficiency & mobility ratioPolymers
OIL CONTAINING COREOIL CONTAINING CORE
FRACTURES
INJECTION FLUID CAN CHANNEL THROUGH LARGE FRACTURES AND BY-PASS OIL
POLYMERS USED IN EORPOLYMERS USED IN EOR
highhighfairfairfairfair100100ooCCScleroglucanScleroglucanhighhighfairfairfairfair5050ooCCXanthan gumXanthan gummediummediumpoorpoorfairfair9090ooCCAMPS copolymerAMPS copolymerlowlowpoorpoorpoorpoor7575ooCCPolyacrylamidePolyacrylamide
COSTCOSTHIGH HIGH SHEARSHEAR
HIGHHIGHTDSTDS
HIGH HIGH TEMPTEMP
POLYMERPOLYMER
EFFECT OF SALT ON VISCOSITYEFFECT OF SALT ON VISCOSITY
200 cps
70cps
20cps
TWO PRIMARY MECHANISMSIN CHEMICAL EOR
Reduce interfacial forcessurfactants
Improve sweep efficiency & mobility ratioPolymersViscoelastic surfactants
VISCOELASTIC SURFACTANTVISCOELASTIC SURFACTANT
•• Forms viscoelastic solution at 0.1Forms viscoelastic solution at 0.1--1.0 wt%1.0 wt%•• Reduces IFT to below 0.01 mN/m Reduces IFT to below 0.01 mN/m •• Tolerant to high TDS and hardnessTolerant to high TDS and hardness•• Shear thinning and reversibleShear thinning and reversible•• Viscosity is reduced when contacted with oilViscosity is reduced when contacted with oil•• Diverts injection fluid to oil bearing sitesDiverts injection fluid to oil bearing sites•• Thermal stability above 150CThermal stability above 150C
POLYMERS USED IN EORPOLYMERS USED IN EOR
highhighfairfairfairfair100100ooCCScleroglucanScleroglucanlowlowexcellentexcellentexcellentexcellent150150ooCCViscoelastic surf.Viscoelastic surf.
highhighfairfairfairfair5050ooCCXanthan gumXanthan gummediummediumpoorpoorfairfair9090ooCCAMPS copolymerAMPS copolymerlowlowpoorpoorpoorpoor7575ooCCPolyacrylamidePolyacrylamide
COSTCOSTHIGH HIGH SHEARSHEAR
HIGHHIGHTDSTDS
HIGH HIGH TEMPTEMP
POLYMERPOLYMER
EFFECT OF SHEAR ON EFFECT OF SHEAR ON VISCOELASTIC SURFACTANTVISCOELASTIC SURFACTANT
0
10
20
30
40
50
60
0 10 20 30 40 50 60 70
RPM
VISC
OSI
TY, C
PS
EFFECT OF TEMPERATUREEFFECT OF TEMPERATURE0.5% @150C0.5% @150C
150
160
170
180
190
200
1 10 100 1000
DAYS
VISC
, CPS
MECHANISM OF MECHANISM OF VISCOELASTIC SURFACTANT VISCOELASTIC SURFACTANT
FLOODSFLOODS
WATER FLOODWATER FLOOD
Water channels through Water channels through the formationthe formation
WATER FLOODWATER FLOOD
InjectorInjector ProducerProducer
WATER FLOODWATER FLOOD
InjectorInjector ProducerProducer
WATER FLOODWATER FLOOD
InjectorInjector ProducerProducer
WATER FLOODWATER FLOOD
InjectorInjector ProducerProducer
WATER FLOODWATER FLOOD
InjectorInjector ProducerProducer
WATER FLOODWATER FLOOD
InjectorInjector ProducerProducer
WATER FLOODWATER FLOOD
InjectorInjector ProducerProducer
WATER FLOODWATER FLOOD
InjectorInjector ProducerProducer
SURFACTANT FLOODSURFACTANT FLOOD
Surfactant follows the Surfactant follows the water channels through water channels through
the formationthe formation
SURFACTANT FLOODSURFACTANT FLOOD
InjectorInjector ProducerProducer
SURFACTANT FLOODSURFACTANT FLOOD
InjectorInjector ProducerProducer
SURFACTANT FLOODSURFACTANT FLOOD
InjectorInjector ProducerProducer
SURFACTANT FLOODSURFACTANT FLOOD
InjectorInjector ProducerProducer
SURFACTANT FLOODSURFACTANT FLOOD
InjectorInjector ProducerProducer
SURFACTANT FLOODSURFACTANT FLOOD
InjectorInjector ProducerProducer
SURFACTANT FLOODSURFACTANT FLOOD
InjectorInjector ProducerProducer
SURFACTANT FLOODSURFACTANT FLOOD
InjectorInjector ProducerProducer
SURFACTANT FLOODSURFACTANT FLOOD
InjectorInjector ProducerProducer
SURFACTANT FLOODSURFACTANT FLOOD
InjectorInjector ProducerProducer
VISCOELASTIC SURFACTANT VISCOELASTIC SURFACTANT FLOODFLOOD
Injection fluid containing Injection fluid containing viscoelastic surfactant seeks viscoelastic surfactant seeks
out oilout oil--bearing channels, bearing channels, blocks water channelsblocks water channels
VISCOELASTIC SURFACTANTVISCOELASTIC SURFACTANT
InjectorInjector ProducerProducer
VISCOELASTIC SURFACTANTVISCOELASTIC SURFACTANT
InjectorInjector ProducerProducer
VISCOELASTIC SURFACTANTVISCOELASTIC SURFACTANT
InjectorInjector ProducerProducer
VISCOELASTIC SURFACTANTVISCOELASTIC SURFACTANT
InjectorInjector ProducerProducer
VISCOELASTIC SURFACTANTVISCOELASTIC SURFACTANT
InjectorInjector ProducerProducer
VISCOELASTIC SURFACTANTVISCOELASTIC SURFACTANT
InjectorInjector ProducerProducer
VISCOELASTIC SURFACTANTVISCOELASTIC SURFACTANT
InjectorInjector ProducerProducer
VISCOELASTIC SURFACTANTVISCOELASTIC SURFACTANT
InjectorInjector ProducerProducer
VISCOELASTIC SURFACTANTVISCOELASTIC SURFACTANT
InjectorInjector ProducerProducer
VISCOELASTIC SURFACTANTVISCOELASTIC SURFACTANT
InjectorInjector ProducerProducer
VISCOELASTIC SURFACTANTVISCOELASTIC SURFACTANT
InjectorInjector ProducerProducer
01020304050607080
0 25 50 75
PV Injected
% R
ecov
ery
OO
IP
%OOIPCUM,%
15 PV water
35000 TDS, 1700 Ca/Mg35000 TDS, 1700 Ca/Mg0.1% surfactant0.1% surfactant0.6% smart surfactant0.6% smart surfactant
US PATENT 7,373,977US PATENT 7,373,977
01020304050607080
0 25 50 75
PV Injected
% R
ecov
ery
OO
IP
%OOIPCUM,%
15 PV water
15 PV surfactant
15 PV water
35000 TDS, 1700 Ca/Mg35000 TDS, 1700 Ca/Mg0.1% surfactant0.1% surfactant0.6% smart surfactant0.6% smart surfactant
01020304050607080
0 25 50 75
PV Injected
% R
ecov
ery
OO
IP
%OOIPCUM,%
15 PV water
15 PV surfactant
2 PV viscoelastic surfactant15 PV water
35000 TDS, 1700 Ca/Mg35000 TDS, 1700 Ca/Mg0.1% surfactant0.1% surfactant0.6% viscoelastic surfactan0.6% viscoelastic surfactan
01020304050607080
0 25 50 75
PV Injected
% R
ecov
ery
OO
IP
%OOIPCUM,%
15 PV water
15 PV surfactant
2 PV viscoelastic surfactant15 PV water
13 PV water
35000 TDS, 1700 Ca/Mg35000 TDS, 1700 Ca/Mg0.1% surfactant0.1% surfactant0.6% viscoelastic surfactan0.6% viscoelastic surfactan
VISCOELASTIC SURFACTANT VISCOELASTIC SURFACTANT STRUCTURESTRUCTURE
WorkWork--like viscoelastic like viscoelastic surfactant micelles for viscositysurfactant micelles for viscosity
CosurfactantCosurfactant for low IFTfor low IFT
APPLICATION OF VISCOELASTIC APPLICATION OF VISCOELASTIC SURFACTANTSSURFACTANTS
Viscoelastic Surfactants Alone Viscoelastic Surfactants Alone ––•• Tight formations, high temperatures, high Tight formations, high temperatures, high
salinitiessalinities
Viscoelastic Surfactants With Polymers Viscoelastic Surfactants With Polymers --•• High viscosity oils, polymer gives residual High viscosity oils, polymer gives residual
viscosity when contacting oilviscosity when contacting oil
US PATENT 7,373,977US PATENT 7,373,977
RESIDUAL OIL RECOVERY TEST
0.01.02.03.04.05.06.0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
FRACTION (0.5 pore volume each)
OIL
/FRA
CTIO
N (g
)
010203040506070
%CU
M.O
IL
RECO
VERE
D
Begin Surfactant Addition0.3 Pore Volume, 0.5%
APPLICATION OF VISCOELASTIC APPLICATION OF VISCOELASTIC SURFACTANTSSURFACTANTS
Viscoelastic Surfactants Alone Viscoelastic Surfactants Alone ––•• Tight formations, high temperatures, high Tight formations, high temperatures, high
salinitiessalinities
Viscoelastic Surfactants With Polymers Viscoelastic Surfactants With Polymers --•• High viscosity oils, polymer gives residual High viscosity oils, polymer gives residual
viscosity when contacting oilviscosity when contacting oil
US PATENT 7,373,977US PATENT 7,373,977
VISCOELASTIC SURFACTANT WITH VISCOELASTIC SURFACTANT WITH POLYMER IN SEA WATERPOLYMER IN SEA WATER
11110.00510.0051D+ED+EGG9090C+EC+EFF10102.82.80.010% polyacrylamide0.010% polyacrylamideEE2.72.70.00420.0042A+B after oil contactA+B after oil contactDD8181A+B before oil contactA+B before oil contactCC62620.0920.0920.45% viscoelastic0.45% viscoelasticBBPptPptPptPpt0.05% anionic surfactant0.05% anionic surfactantAAViscVisc, cps, cpsIFT,mN/mIFT,mN/mDescriptionDescription
CONCLUSIONSCONCLUSIONSViscoelastic surfactants have been developed Viscoelastic surfactants have been developed that provide both low IFT and high viscosity in that provide both low IFT and high viscosity in injection fluidsinjection fluidsUnlike polymers, viscoelastic surfactants are Unlike polymers, viscoelastic surfactants are not permanently degraded by high shear.not permanently degraded by high shear.Also, unlike polymers their viscosity building Also, unlike polymers their viscosity building characteristics are not reduced by high characteristics are not reduced by high electrolyte concentrations. electrolyte concentrations. Viscoelastic systems can be designed to Viscoelastic systems can be designed to tolerate both high temperature and high salinity tolerate both high temperature and high salinity conditions.conditions.
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12822 Park One Drive12822 Park One DriveSugar Land, TX 77478Sugar Land, TX 77478
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