This is prepaired by Satyajit et al . the slides are giving introduction of Bioremediation of oil contaminatted soil.

1. BIOREMEDIATION
AND
MICROBIAL ENHANCED OIL
RECOVERY
SATYAJIT PRADHAN
DARSHI PATNI
NEHA OLI

2. WHAT IS BIOREMEDIATION?
It is a process which uses naturally occurring
microorganisms to enhance normal biological
breakdown.
How does it work?
Microorganisms break down petroleum based
compounds and convert them to carbon dioxide and
water, eliminating the oil and grease in the cleaning
solution and eliminating the need to transport hazardous
materials.

3. Types of bioremediation
In-situ: This involves treating the
contaminated material at the site.
Ex-situ: When bioremediation is carried
out by displacement of the
contaminated soil to another site for
treatment.

4. Several factors influence the success of
bioremediation:
1. The type of bacteria present at the site
2. The physical and chemical characteristics of the
oil and the oil surface area.
The three main approaches to oil-spill
bioremediation are:
1. Bio augmentation: Oil-degrading bacteria are
added to supplement the existing microbial
population.

5. 2. Bio enhancement: Nutrients or other
growth limiting substances are added to
stimulate the growth of indigenous oil
degraders.
3. Bio stimulation:The use of indigenous
microbes to promote the growth of native
microbes, already present in the soil, so as
to modify the site for bioremediation.

6. WHY BIOREMEDIATION?
Freezing of oil, deposition of semi-solid compounds
and rusting of steel cause rupture of pipelines
leading to oil spills. This becomes an important
environmental concern.
Of all the different processes available for clean-up
of sites, bioremediation is the best and most cost
effective method for remediation, with respect to
environmental liability.
Thus, it serves as a cheap, eco-friendly solution to
clean the land and sea of oil spills.

7. OIL ZAPPER
It is developed by TERI after seven years of research work
and partly supported by the DBT (Department of
Biotechnology), Ministry of Science and Technology,
Government.
The Oilzapper is neatly packed into sterile polythene bags
and sealed aseptically for safe transport.
The shelf life of the product is three months at ambient
temperature.

8. What is Oil zapper?
1. It is a consortium of four bacterial strains.
2. Each bacteria feeds on different layers of crude oil i.e.
a) waxy element/ saturated hydrocarbons
b) aromatic component/ benzene compounds.
c) NSO (compounds of nitrogen and sulphur)
d) Asphaltene or tar
It thus degrades the total petroleum hydrocarbon by its
metabolic processes, converting hazardous substances into
water, carbon dioxide and fatty acids.

9. 1.A carrier material is used along with oil zapper.
2.It is an organic plant material(powdered corncob).
3.It helps in retaining moisture in contaminated soil
and creates air pockets in soil, thus requiring less
water.
4.This increases the rate of bioremediation.
5. The sludge eating bacteria can increase in
number when an oily sludge is available.
6. When the contaminated is bio remediated, the
microbial population naturally declines.

10. How does oil zapper act?
Crude oil contains hydrocarbon chains. Bacteria’s enzyme
will catalyse the insertion of oxygen into the hydrocarbon,
so that the molecule can subsequently be consumed by
cellular metabolism.
Carbon hydrogen bond is an excellent source of energy for
the bacteria in oil zapper. So, it gets easier to degrade the
petroleum product.
The microbes used are either present in the environment,
or they can be added by culture grown from other
contaminated areas or being genetically engineered.

11. METABOLIZING ACTION BY MICROBES

12. OIL- CONTAMINATED SOIL

13. MEOR—Microbial Enhanced Oil
Recovery
The MEOR technology involves the use of
specific microbes capable of producing
useful metabolites (gases, solvents,
surfactants, polymer, acids etc.) to
recover additional oil from depleted
petroleum reservoirs.

14. Why MEOR?
 Ageing of wells is a perpetual and crucial concern that the
global oil industry faces.
 Thousands of oil wells lie abandoned—they are either
unproductive or yield oil in insignificant quantities.
 An oil well becomes sick when approximately 30% of oil in
place has been recovered.
 The reason: natural gas in the reservoir (responsible for
pushing oil up to the mouth of the well) diminishes in
quantity and loses pressure because of deep extraction.

15. As a result, the oil flow decreases and eventually
stops. These so-called dead or sick wells still have a
substantial quantity of oil left in them.
Conventional methods of recovery are extremely
expensive and costs can vary from 140 000 to 200
000 dollars per well.
However, as oil reserves dry up globally, the depth of
wells increases, and
temperatures inside the reservoirs also increase (it
varies between 80 °C and 120 °C),these methods
prove ineffective and the task becomes more
challenging.

16. So the technique on MEOR is used, in which
hyperthermophilic microbes are used to extract
the remaining oil from the so-called dead or sick
wells.

17. Outcomes of MEOR
 The outcomes of MEOR are explained based on two
predominant rationales:
 Increment in oil production- This is done by modifying
the interfacial properties of the system oil-water-
minerals, with the aim of facilitating oil movement
through porous media.
 In such a system, microbial activity affects
fluidity (viscosity reduction, miscible flooding);
displacement efficiency (decrease of interfacial tension,
increase of permeability); sweep efficiency (mobility
control, selective plugging) and driving force (reservoir
pressure).

18.  Upgrading- In this case, microbial activity acts may
promote the degradation of heavy oils into lighter ones.
Alternatively, it can promote desulfurisation due
to denitrification as well as the removal of heavy metals.

19. Advantages of MEOR
 Injected microbes and nutrients are cheap; easy
to handle in the field and independent of oil
prices.
• Economically attractive for mature oil fields
before abandonment.
• Increases oil production.
• Existing facilities require slight modifications.
• Easy application.
• Less expensive set up.

20.  Low energy input requirement for microbes to
produce MEOR agents.
 More efficient than other EOR methods when
applied to carbonate oil reservoirs.
 Microbial activity increases with microbial
growth. This is opposite to the case of other EOR
additives in time and distance.
 Cellular products are biodegradable and
therefore can be considered environmentally
friendly.

21. Disadvantages of MEOR
 The oxygen deployed in aerobic MEOR can act as corrosive
agent on non-resistant topside equipment and down-hole
piping
 Anaerobic MEOR requires large amounts of sugar limiting its
applicability in offshore platforms due to logistical problems
 Exogenous microbes require facilities for their cultivation.
 Indigenous microbes need a standardized framework for
evaluating microbial activity, e.g. specialized coring and
sampling techniques.
 Microbial growth is favoured when: layer permeability is
greater than 50 md; reservoir temperature is inferior to 80 0C,
salinity is below 150 g/L and reservoir depth is less than
2400m.

22. Classification of MEOR
MEOR is classified as :-
Surface MEOR and underground MEOR based on the
place where microorganisms work.
 Surface MEOR, bio-surfactant , biopolymer (xanthan
gum), and enzyme are produced in the surface facilities.
These biological products are injected into the target
place in the reservoirs as chemical EOR methods.
 Underground MEOR, microorganisms, nutrients and/or
other addictives are injected into the reservoir and let
them sustain, grow, metabolize, and ferment
underground.

23. Two microbial consortia used in
MEOR are:-
 Used in pipe -
IRSM-1 –Clostridium, Bacillus
Thermophilic 45-65º C, Halophilic, Anaerobic
Or
PDS10- Geobacillus kaustophillus Thermophilic – upto
90⁰C but optimum activity at 55⁰C, Anaerobic
 Used in reservoir-
S-2 -Three Hyperthermophilic
Hyperthermophilic to 90º C, Halophilic, Barophilic,
Anaerobic

24. Properties of microbes used in
MEOR
General properties of microbes:-
• Small Size
• Resistant to High Temperatures
• Resistant against High Pressure
• Capability of Withstand Brine and Seawater
• Anaerobic Using of Nutrients
• Unfastidious Nutritional requirements
• Appropriate Biochemical Construction for Production
Suitable Amounts of MEOR Chemicals
• Lack of any Undesirable Characteristics

25. MICROBES IN THE PIPE:-
• The microbes are :-
Thermophilic consortium (90⁰C,optically active at
55⁰C)
Micro aerophilic consortium
• Non pathogenic
• Gram negative
• Carbon source:- glucose and wax
• pH – 6 to 8
• Incubation period – 7 days

26. MICROBES IN THE RESERVOIR:-
•The microbes are HYPERTHERMOPHILIC –
•Obligate anaerobes(-300 to -400 redox)
•Thermophilic (90º C, attempt to 110º C)
•Halophilic (7-4% salinity)
•Barophilic (4500 psi)
•Acidogenic (~pH 4.0)
•Gram negative
•Non pathogenic.
•Carbon source :- Sugar cane
•Nitrogen source:- Urea, Ammonium sulfate

27. Effects:
• Gases, increase reservoir P, push oil out with gas drive
• Gases, solvents and weak acids reduce viscosity: oil
gets thinner
and flows more freely
• Surfactants (e.g. glycolipids, lipopeptides) emulsify oil-
water, reduce surface tension and interfacial tension
• Acids, dissolve carbonates, increase perm
• Biopolymers, plug thief zones, access of secondary
pathways
• Bio films, influence on flow properties

28. How it works?
• A large volume (120 cubic meters) of
bacterial culture with nutrient in aqueous
media is pumped into well (wells must have
significant water cut in order to facilitate
bacterial growth).
• Well is kept shut-in for a significant period
(almost for about 21 days) to allow bacterial
growth.
• In nutrient broth bacteria rapidly multiply.
• CO2, volatile fatty acids and bio-surfactants
are released as the bacteria consume
nutrient feed.

29. •Generated acids dissolve rock, clean the pores
and improve absolute permeability.
•Produced gases re-pressurize the pores and
push oil out of pore spaces & reduce oil
viscosity.
•Produced bio-surfactants reduce interfacial
tension between oil and water and facilitate
mobilization of trapped oil.
•Production of biopolymers increase water
viscosity and improve mobility ratio.
•Bio-film developed on solid surface
physically displace oil.

30. Paraffin Deposition Bacteria
and
Wax Deposition Prevention
Method:-
 When the oil is completely removed or taken out from the
reservoir to column pipe , its temperature decreases from
about 90⁰C to 50 -60⁰C.
 As the temperature decreases the wax and paraffin present in
the crude oil start solidifying and narrowing the column.
 A microbe PDS10 (Paraffin Degrading Strain) is used to remove
those solidified wax and paraffin. (Growth time is 5 days, add
30-40cubic meters of growth culture in the pipe)
 The microbe metabolizes wax and paraffin into CO2 H2O and
simpler products.
 Biofilm is formed by bacteria which does not let oil or wax to
adhere on the surface of the pipe.

31.  When the wax starts depositing inside the pipes present
on the surface of the earth (due to very low temp i.e.,
37⁰C), WDP (Wax deposition Preventive strains) is added.
(growth time 5 days and 30cubic meters of growth
culture is added in the pipe)
 The same process is activated. Wax is metabolized by the
bacteria present in the growth culture and biofilm is
formed.
 Due to this, oil doesn’t stick at the surface of the pipes
and we get a good production in an oil reservoir.

33. Oil and Natural Gas Corporation
MEOR Projects, India
The MEOR technology, when applied in 25 oil wells of
ONGC, extracted 4500 cubic metres of oil from one of
the sick wells, translating into revenues of more than
675 000 dollars.
The Company plans to use the technology for other sick
oil wells in Gujarat and Assam.
Its benefits such as cost effective use and environment-
friendly nature have generated interest among oil firms
in the Middle East and other oil-producing countries.

34. Summary and Conclusions
Up to 3 fold increase in oil production
Significant reduction in water cut
Longevity of 8-12 months
Indigenous formation-organisms were most
successful
Incremental pay back of 2 to 3 months
» formation characteristics
» source of microbes.
Cost/bbl and payback:
» Thermophilic consortium $3/bbl in 2 months
(IRSM-1 culture)
» Hyperthermophilic consortium $6/bbl in 3
months (S-2 culture)