1. USE OF MICROBES IN MINERAL
BENEFICIATION AND OIL RECOVERY
presented by
Essam Yahya

2.  Currently global energy production from fossil
fuels is about 80-90% with oil and gas representing
about 60 %
 During oil production, primary oil recovery can
account for between 30-40 % oil productions
 While additional 15-25% can be recovered by
secondary methods such as water injection leaving
behind about 35-55 % of oil as residual oil in the
reservoirs
 This residual oil is usually the target of many
enhanced oil recovery technologies and it amounts
to about 2-4 trillion barrels. 2
Introduction

3. 3
Enhanced oil recovery (EOR) methods
 Enhanced oil recovery (EOR) methods aimed to recover additional oil after
primary recovery or natural drives in the reservoirs
 Water flooding (water injection).
 Gas injection (not miscible).
 Carbon dioxide flooding (miscible).
 Steam injection and in-situ burning.
 Surfacants or foams injection.
 Microbial Enhanced Oil Recovery Methods.

4. Primary Oil Recovery
 The initial stage of producing oil from a reservoir.
Primary recovery: natural mechanisms (5-10%).
Natural gas expansion
 Use natural forces such as:-
- expansion of oil, gas or both
- displacement by naturally pressurized water
- drainage from a reservoir in high elevation to a well
in lower elevation
- artificial techniques (pumps)

5. Secondary Oil Recovery
 Injection of fluids in a series of wells to
force oil into another series of wells.
 Essentially augmenting the natural
forces used in primary methods.
 Water flooding.
Secondary recovery: fluïd injection (25-
30%)
Water or natural gas circa 65% not
recovered

6. Tertiary or enhanced oil recovery
 Tertiary or enhanced oil recovery (EOR):
o Gas injection.
o Thermal recovery (TEOR).
o Chemical injection
• Alkaline, surfactant, polymer and MICRO-ORGANISMS.
• MEOR Extra 20-30% recovery!
6

7. 7
What is microbial enhanced oil recovery (MEOR)?
Use of microbes to improve oil recovery, established by
Beckman 1926.
How much additional oil can be produced? Up to 60% oil in
place after primary recovery.

9. 9
Schematic of MEOR Technology

10. 10
MEOR Mechanisms
Bioproduct Effect
Acids
Biomass
Gases (CO2, CH4, H2)
Solvents
Surface-active agents
Polymers
Modification of reservoir rock
Improvement of porosity and permeability
Reaction with calcareous rocks and CO2 production
Selective or non selective plugging
Emulsification through adherence to hydrocarbons
Modification of solid surfaces
Degradation and alteration of oil
Reduction of viscosity and oil pour point
Desulfurization of oil
Reservoir repressurization
Oil swelling
Viscosity reduction
Increase permeability due to solubilization of carbonate rocks by
CO2
Dissolving of oil
Lowering of interfacial tension
Emulsification
Mobility control
Selective and non-selective plugging

11. MEOR Application
 During last 15 years some countries began to develop and apply MEOR methods
successfully again such as USA, Russia, Romania, Germany, Malaysia, China,
India, Norway, UK, Venezuela, Iran, Trinidad among others.
 More than 300 cases of MEOR methods application – mostly of single well
stimulation – were reported.
 MEOR Application
1. Selective Plugging
2. Hydrocarbon Chain Degrading Bacteria
3. Cyclic Microbial Recovery

12. 1. Selective Plugging Recovery:
 Microbes of activated sludge and bio-stimulators
application on the last stage of carbonate rock field
development.
 Totally during 1996-2002, 68 injectors were
treated.
 1 t of bio-product gave up to 756 t of oil.
Microbes plug the washed out tunnel forcing
water to flow through yet unwashed areas.

13. 2. Microbiological Stimulation for Oil Recovery
Stimulating naturally occurring bacteria that feed on
oil to create conditions that release residual oil from
the reservoir.
 The interfacial tension between water and oil is
lowered resulting in easier oil recovery.
Stat oil
• Applying an aerobic MEOR technique to the development of
Norne field.
• Considers that the technique will produce about 32 million
incremental barrels; about 6% above what would otherwise have
been recovered.
Carbon hungry bacteria are injected by Statoil
into the Norne field to free oil clinging to the
reservoir rock and enhanced recovery

14. 3. Hydrocarbon Chain Degrading Bacteria
Viscous Oil
(Bokor Field Malaysia)
Before
Treatment
After Treatment Over past 5
months
(post MEOR)
Production rate 152 b/d 334 b/d
Water cut 75 % 45 %
Heavy oil field in
Western Siberia,
Russia, January, 2006
Before
Treatment
After Treatment For a Period 3
Months
Production rate 5 - 7 m3/h 15 -19 m3/h (mostly 16-17 m3/h)
Water cut 48 % 25 %
Quality of oil - improved
 A large group of bacteria is able to cut hydrocarbon chains
thus decreasing the viscosity of oil.
 The microbes degrade hydrocarbons to the following
components.

15.  Microbes replicate -process is self sustaining.
 Eliminates logistical hassle.
 Find their own carbon source in the reservoir.
 Create recovery enhancing chemicals where
needed.
 A Rather cheap method compared to CO2
injection.
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The Best Part of MEOR
Self-propagating
Self- directing

16. Q1 What are the most common Enhanced oil recovery (EOR) methods ?
Q2 explain the main differences between primary and secondary oil
recovery, and why we need to go for the tertiary oil recovery?