Laboratory core flooding experiments using Bio-surfactant and molasses: Implications for Microbial EOR
Mohammad Bahar, Keyu Liu, Abdul Rashid ,Xiaofang Wei, Tara Sutherland, Xiaoyi Wang, Manzur Ahmed, Phil Hendry, Dongmei Li, Se Gong, Herbert Volk, S. Razak, Wan Ata, A Azhan,M.RizalCSIRO Wealth from Ocean Flagshipand Petronas Research
30th IEA Annual Workshop and symposium on EOR -Canberra
Outline
• Background
• Objectives
• Materials and methods
• Results and discussion
• Conclusions
30th IEA Annual Workshop and symposium on EOR -Canberra
Oil Recovery Mechanisms
CONVENTIONAL RECOVERY
EOR
TERTIARYRECOVERYTERTIARY
RECOVERY
SECONDARYRECOVERY
SECONDARYRECOVERY
PRIMARYRECOVERYPRIMARY
RECOVERY NaturalFlow
NaturalFlow
Artificial Lift(Pump, Gas Lift, etc.)
Artificial Lift(Pump, Gas Lift, etc.)
WaterfloodWaterflood Pressure Maintenance(Water, Gas Reinjection)Pressure Maintenance
(Water, Gas Reinjection)
ThermalThermal SolventSolvent ChemicalChemical MEORMEOR
Adapted from the Oil & Gas Journal, Apr 23, 1990
OtherOther
30th IEA Annual Workshop and symposium on EOR -Canberra
EOR vs. Permeability
HydrocarbonMiscible
Nitrogen andFlue Gas
CO2
MiscibleSurfactantPolymer
Polymer
Alkaline
Fireflood
Steam Drive
EOR Method
Not critical if uniform
Not critical if uniform
High enough for good injection
Permeability (md)10 100 1,000
Good Possible Fair Difficult Not Feasible
MEOR
Dr. Larry Lake, Oilfield Review (Jan. 1992)
30th IEA Annual Workshop and symposium on EOR -Canberra
Oil Gravity vs. EOR Methods
0 10 20 30 40 50 60Oil Gravity oAPI
N2 & Flue GasN2 & Flue Gas
HydrocarbonHydrocarbon
CO2 - MiscibleCO2 - Miscible
Immiscible GasImmiscible Gas
Alkaline/Surfactant/PolymerAlkaline/Surfactant/Polymer
Polymer FloodingPolymer Flooding
Gel TreatmentsGel Treatments
MEORMEOR
Steam FloodingSteam Flooding
MiningMining
(Modified from J.J. Taber, F.D. Martin & R.S. Seright, 1997)
30th IEA Annual Workshop and symposium on EOR -Canberra
• Microbes can be introduced into oil reservoirs, and/or indigenous microbes can be stimulated with nutrients.
Potentials:• Changing fluid properties such as Density, Viscosity,
composition and IFT• Changing the rock properties such as wettability ,
permeability and relative permeability• Changing conditions of system (pressurize,
What is MEOR and its Potential on EOR?
30th IEA Annual Workshop and symposium on EOR -Canberra
Background: Can MEOR be a successful method for EOR?
With biosurfactant (above CMC)
S.M. Farouq Ali- University of Calgary-2003
Initial
30th IEA Annual Workshop and symposium on EOR -Canberra
Overview of CSIRO’s MEOR project
MicrobiologyMicrobial physiologyMicrobial metabolismsIsolation and culture
before and after Microorganisms treatmentsMeasuring fluid physical properties, such as density, viscosity and IFTMeasuring rock physical properties K, Krw, Kro, Measuring EOR
Organic GeochemistryDevelop analytical protocolidentify/quantify metabolites
ModellingAnalyse/verify experimental resultsBuild predictive model for MEOR Build reservoir model for field trial
30th IEA Annual Workshop and symposium on EOR -Canberra
• Monitor changes in oil and water physical properties after culture experiments
• Detect and quantify various by-products
- Gases- Bio-surfactants- Acids- Co-biosurfactants
- Polymer - Oil Degradation
• Select suitable nutrients to stimulate microbial growth and production of metabolites leading to MEOR
• Undertake core flooding experiments
Objectives
30th IEA Annual Workshop and symposium on EOR -Canberra
• Reservoir fluids from Off-shore Malaysian oil-field
- Depth: ~ 720 m
- Temperature: 50ºC
- Salinity: 2.3 %
- Mature, high water cut
- Reservoir Pressure: 940 Psia
Material and methods
30th IEA Annual Workshop and symposium on EOR -Canberra
Experiment : Core Flooding Setup
30th IEA Annual Workshop and symposium on EOR -Canberra
Experimental sequences
Oil
Water
Molasses
Water
Water
Measuring volume ofWater
OilGas
Core Holder
30th IEA Annual Workshop and symposium on EOR -Canberra
Effects of biosurfactant on water densitiesEffect of Bio-surfactant concentration on density of Bokor formation water
for Well 104 LS
0.99
0.995
1
1.005
1.01
1.015
1.02
0 10 20 30 40 50 60 70
Temperature (oC)
Den
sity
(g
m/c
c)
Base Case
Bio - Surfactant - 40 ppm
Bio-surfactant - 150 ppm
No effects
30th IEA Annual Workshop and symposium on EOR -Canberra
Effects of bio-surfactant on viscosity of Bokor formation water (104LS)
Effect of Bio-surfactant on viscosity of Bokor formation water
0.4
0.5
0.6
0.7
0.8
0.9
1
1.1
1.2
0 10 20 30 40 50 60 70
Temperature (oC)
Vis
cosi
ty (
cp)
No - Biosurfactant
Bio-surfactant - 40 ppm
Bio-surfactant - 150 ppm
H2O viscosity increases with BS concentrations
30th IEA Annual Workshop and symposium on EOR -Canberra
Effect of bio-surfactant (Surfactin) on IFT (104LS) at 50 °C
0
2
4
6
8
10
12
14
0 200 400 600 800 1000
Pressure (psi)
IFT
(d
ynes
/cm
)
No - Surfactant
Bio-surfactant - 40 ppm
Bio-Surfactant - 150 ppm 940psi
30th IEA Annual Workshop and symposium on EOR -Canberra
MEOR core flooding results
0.0
1.0
2.0
3.0
4.0
5.0
0.0 0.2 0.4 0.6 0.8 1.0 1.2Volume of Water Injected (pv)
% E
OR
4.1% MEOR
Sor=25.6%
Swir=14%; Primary oil recovery: 74.4%Soir=25.6%; incremental EOR: 4.1%
30th IEA Annual Workshop and symposium on EOR -Canberra
Which phenomena is more reliable?
Injecting Molasses
Increasing production 4%
?
30th IEA Annual Workshop and symposium on EOR -Canberra
What types of by-products were produced?
• Gases• Alcohols• Acids• Bio-surfactants• Micro-emulsion
30th IEA Annual Workshop and symposium on EOR -Canberra
Gases and swelling
• A large reduction in oil viscosity and small increase in water viscosity
The Young – Laplace Equation predicts an inverse relation of pressure drop with Swelling of Oil
21 R
1
R
1γΔP
30th IEA Annual Workshop and symposium on EOR -Canberra
Distribution of microbial gases
CO2 CH4 C2H6 C3H8 C4H10
Con
cent
ratio
n (p
pm)
• Stimulation by carbohydrates produced substantial amounts of CO2 and CH4 gases
• C2+ gases desorbed from oil?
0E+0
2E+4
4E+4
6E+4
8E+4
1E+5
1E+5
Molasses only Microbes with molasses Microbes without molasses
30th IEA Annual Workshop and symposium on EOR -Canberra
Microbial gases
Duration of culture (days)(Control)
2 2 4 7 9 11 16 18 21 310.0E+0
2.0E+4
4.0E+4
6.0E+4
8.0E+4
1.0E+5
CO2
CH4
Con
cent
ratio
n (p
pm)
• Very high amounts of CO2 and CH4 gases produced
• CO2 generation continued to increase until after 9 days
• CH4 generation continued to increase until after 11 days
30th IEA Annual Workshop and symposium on EOR -Canberra
Alcohols production
• Variable amounts of alcohols produced
• Generation continued to increase until after 16 days of culture
• A second cycle of moderate generation initiated after 18 days
ng/m
L of
wat
er
Duration of culture (days)
2(Control)
2 4 7 229 11 14 16 18 20
0
100
200
300
1-Butanol, 2- + 3-methyl
0
20
40
60
1-Pentanol
0
100
200
300
1-Propanol
30th IEA Annual Workshop and symposium on EOR -Canberra
0
200
400
600
Acetic acid
0
50
100
150
Propanoic acid
0
25
50
75
100
Butanoic acid, 2-methyl
ng/m
L of
wat
er
Duration of culture (days)
2(Control)
2 4 7 229 11 14 16 18 20
Acids production
• Variable amounts of acids produced
• Consistent with gases and alcohols, generation continued to increase until after 16 days of culture
• A second cycle of intense generation initiated after 18 days
30th IEA Annual Workshop and symposium on EOR -Canberra
Micro-emulsion experiment using co-surfactant
30th IEA Annual Workshop and symposium on EOR -Canberra
Low Concentration - Surfactant Adsorption
High Concentration - Self-Assembled Surface Aggregates
Moderate Concentration - Hemimicelle Formation
Surfactants at the Solid-Liquid Interface
Clay
Clay
ClayClay
30th IEA Annual Workshop and symposium on EOR -Canberra
Water dropletsOil rim
surfactantsSolubility of alcohol in micelles
30th IEA Annual Workshop and symposium on EOR -Canberra
w/o emulsion
Micelles
Bio-surfactants
30th IEA Annual Workshop and symposium on EOR -Canberra
Water droplets
Oil
30th IEA Annual Workshop and symposium on EOR -Canberra
Water droplets with oil rimOil droplets
in water droplets
5 m
30th IEA Annual Workshop and symposium on EOR -Canberra
Interfacial tension and capillary pressure
• Surfactant Reduce interfacial tension in small pore and reduce the capillary pressure in the system
R1=2
Y=2
P=(2*2)/2=2
R2=1
Y=1
P=(2*1)/1=2
30th IEA Annual Workshop and symposium on EOR -Canberra
Conclusions
• Microorganisms can change the threshold point of residual oil in reservoirs and to enhance oil recovery:
• Core flooding using 40 ppm surfactin enable 3% EOR• Core flooding using 0.875% molasses enable 4.1% EOR
• MEOR uses a combination of mechanisms to recover residual oils in reservoirs including
• Gas production can reduce oil viscosity• Biosurfactant production can reduce IFT • Solvents and biosurfactants can promote micro or nano emulsion• Produced biosurfactants may change the wettability of clay rocks
• MEOR could become a low cost environmental friendly EOR method in the future but more research is required
Contact UsPhone: 1300 363 400 or +61 3 9545 2176
Email: [email protected] Web: www.csiro.au
Thank you
Wealth from Ocean FlagshipMohammad BaharReservoir Engineer
Phone: 08 64368954Email: [email protected]: www.csiro.au/science/MEOR.html