MICROBIAL ENHANCED

OIL RECOVERY

CONTENTS Introduction • EOR• MEOR History Mechanism• Stimulation of oil production• Wellbore cleaning• Selective plugging• Biosurfactants• Microbial products Advantages Disadvantages Environment al issues Current status Conclusion References

TYPES OF ENHANCED OIL RECOVERY

• Primary recovery-12% to 15%oil in well recovered without the need to introduce the other substances into the well.

• Secondary recovery-The oil well flooded with water or other substances to drive out additional 15% to 20% more oil from well.

Poor Sweeping Efficiency

Poor Displacement Efficiency

TERTIARY OIL RECOVERY

• Known as MICROBIAL ENHANCED OIL RECOVERY ,use of microorganisms to additional recover up to 11% more oil from well.

Microbial Enhanced Oil Recovery

• MEOR is use of microorganisms to retrieve additional oil from existing well thereby enhancing oil production from oil reservior.

• Selected microorganisms are introduced into oil wells to produce harmless product such as natural substances or gases which propel the oil out of well.

HISTORY

• 1936 Beckman proposed the utilisation of microbes for enhanced oil recovery.• 1947 Zobell released oil from strata rocks using Desulfovibrio sp.• 1954 Kuznetsov inoculated molasses enriched media and observed the gas production.• 1958 Heinningen proposed the selective plugging with microbial produced biomass

contd…

• 1977 Yakinov observed the strain of

Bacillus licheniformis JF-2 in

enhancement of oil recovery.• 1983 Bubela examined the effects of

reservior env.conditions on

microbial culture.• 2004 McInemey examined the 200 strains of

Bacillus sp.in oil enhancement.

MECHANISMS OF MEOR

• Stimulation of oil production.• Wellbore cleaning.• Selective plugging• Production of Biosurfactants.• Microbial Products

MICROORGANISMS

• Desulfovibrio sp.

• Bacillus sp.

• Clostridium sp.

• Pseudomonas sp.

• Arthrobacter sp.

• Microbacterium sp.

STIMULATION OF OIL PRODUCTION

• Partial repressurisation of reservior by methane and carbon dioxide.

• Reduction of oil viscosity through dissolution of organic solvents in oil phase.

• Increase of reservior permeability and widening of fissures and channels through etching of carbaneous rocks.

WELLBORE CLEANING

• Cleaning of wellbore region by Increasing the average pore size.

• Various metabolites -• Acids - react with various minerals,loosen the clay and deposits.• Solvents - dissolve the precipitated organic deposits.• Biogas – push oil from dead spaces and dislodge debris.

SELECTIVE PLUGGING

Selective plugging of highly permeable zones by injecting slime forming microorganisms,increases the sweeping efficiency and oil recovery.

BIOSURFACTANTS

Biosurfactants are microbially derived surface active agents that can lower the surface tension of oil and act as slippery detergents helping the oil move more freely away from rocks and more easily out of well.

Arthrobacter sp.

Bacillus licheniformis

Bacillus subtilis

Candida lipolytica

Corneybacterium lepus

Nocardia sp.

Pseudomonas sp.

Rhodococcus sp.H13-A

Torulopsis bombicola

Xanthomonas compestris

Trehalose,sucrose,

lipids,fructose

Lipopeptides

Surfactin

Sophorose lipid

Fatty acids

Neutral lipid

Glycolipid

Glycolipid

Sophorose lipid

Xanthan

ADVANTAGES

• Biodegradibility

• Low toxicity

• Environment friendliness.

MICROBIAL PRODUCTS INCREASING OIL RECOVERY

Biomass

Selective plugging.

Modification of solid surface.

Reduction of oil viscosity.

Alternation in flow properties.

BIOGAS

Carbon dioxide(80%)

Increase the pressure

High energy potential in oil field

Hydrogen(20%)

Increase oil volume,

decrease oil viscosity

Give better oil mobilisation

Methane Change pressure potential in fissures,pores

Increase oil production rate

ORGANIC ACIDS

Acetic acid,

propanoic acid,

valerianic acid

Decrease pH up to 4.8

Increase permeability of rocks

Dissolve the carbonate rock

Dissolve carbonate partially building up new flow channels

Methane,

ethanol,

propanol,

butanol

Decreases interfacial tension

Forces the imbibition of injected,fermented molasses media into pore canals to give more oil from rock

Biolipid Alter the rock

Increase wettability

break oil/water barriers creating emulsion leading to improved flow rate

ADVANTAGES OF MEOR

• Cheap • Environmentally acceptable alternative.• Ability to grow on low cost nutrients.• Small size help them to penetrate deep into oil wells

enhancing oil recovery.• Do not consume large amount of energy.

DISADVANTAGES OF MEOR

• Need a standardized framework for evaluating microbial activity.

• Exogenous microbes require facilities for cultivation.• Oxygen deployed in aerobic MEOR act as corrosive

agent on non resistant equipments and pipelines.• Plugging of reservoirs due to aggregation of cell mass

or precipitation of metabolites.

ENVIRONMENTAL ISSUES

(A) Subsurface water Migration of organism or metabolites into groundwater.

(B) Waste water Spent fluids due to additional drilling. Equipment washing. Media and Chemicals used for pH adjustment.(C) Atmospheric emission Hydrogen sulphide production.(D) Solid wastes Bacteria in filter solids.

CURRENT STATUS

• TITAN INC.-Changing the skin surface of microbes to induce a unique oleophilic activity which dislodges and breakdown oil droplets and create natural emulsion.

• New project at Daquing field in CHINA to change the structure of polymers to strengthen their ability to break down the long carbon chains of high density crude oil.

Contd….

• TERI,Delhi and ONGC,Gujarat – Development of Thermophilic paraffin degrading strain consortium S 2 for prevention of paraffin deposition inside the oil well tubing.

BIOTECHNOLOGY AND MEOR

• MEOR is direct application of Biotechnology.Use of Genetic engineering and Recombinant DNA technology to develop the strains of bacteria with oil recovery traits and susceptibility to adverse conditions.

• Recombinant strain of Bacillus mojavensis JF-2,RrB-2 having high efficiency.

CONCLUSION

• MEOR reduces or eliminates the need to use the harsh chemicals during oil drilling .MEOR will become increasingly economically feasible as genetic engineering develops.

• Methods for developing and growing MEOR bacteria are improving, lowering the production cost making it more attractive alternative to traditional chemical methods.

REFERENCES

• Belyaev S.S,Borzenkov I.A,Ibatullin T.N, May 17,2004 Use of microorganisms in Biotechnology for enhancement of oil recovery,Microbiology,vol 73(5):pg 590-598

• Jang L.K, Yen T.F. 1990 ,Mechanism of MEOR In MEOR Principle and practice :pg 158-163

• Microbial enhanced oil recovery,retrieved May 5,2002 from Environmental Biotechnologies inc.www.e-b-t.com/meor.htm

• www.abc.edu/chyn/lect/lect-11 htm• http//findarticals.com/p/articals/mi_m3159• http.//wikipedia.org/wiki/MEOR