1. Adel Sharif University of Surrey a.sharif@surrey.ac.uk
Petroleum Industry uses of Bactria: Microbial Enhanced Oil Recovery (MEOR)
Adel Sharif
University of Surrey
Industrial Uses of Bacteria 19 May 2010, IOM3, London, UK

2. Petroleum Microbiology
MICROBIAL TREATMENT OF PETROLEUM WASTE
Treatment of Contaminated Soils and Sludges 
Factors affecting bioremediation.
Biofiltration of Volatile Organic Compounds
Removal of H2S and SOX
MICROBIAL PROCESSES FOR RECOVERING AND UPGRADING PETROLEUM
Microbial Enhanced Oil Recovery
Microbial Deemulsification
Microbial Desulfurization     
Microbial Denitrogenation
Enzymatic Upgrading of Petroleum Fractions and Pure Hydrocarbons
BACTERIAL BIOSENSORS

3. Oil formation

4. Oil Recovery Methods Primary (natural reservoir energy) (15-20%)
- Solution Gas Drive (depletion).
- Gas Cap Drive.
- Natural water Drive.

5. Secondary oil Recovery method (30-35%)
- Water Injection.
- Gas Injection.
- WAG method.

6. Tertiary Oil Recovery method (30-50%)
- Thermal Injection (steam).
- Chemical Injection (Polymer).

7. Oil Recovery Techniques
During primary stage only 15-20% oil can be recovered naturally.
Another 15-25% can be recovered during the secondary stage through water injection.
Tertiary stage (of steam injection) is too expensive to be used.
Hence, nearly 50% of the oil still needs to be recovered.

8. Microbial Enhanced Oil Recovery (MEOR)
What is the solution?
MEOR!
MEOR is a process in which micro-organisms are used to produce surfactants, acids, and/or gases using growth substrates from the fossil fuel, to enhance the oil recovery.

9. Schematic Diagram of MEOR

10. Microbial Enhanced Oil Recovery (MEOR)
MEOR Microorganisms produce
Biosurfactants which decrease the oil viscosity to increase oil flow.
Acids which increase the rock porosity and hence oil flow.
Gases to increase the pressure in the reservoir and improve oil recovery.
Exopolymers and biomass to block the thief zones.

11. MEOR Mechanism

12. MEOR - Objectives
Developing an MEOR technology, to be implemented in the oil fields to recover the oil during the secondary/tertiary stage.
Isolating suitable microorganisms from the samples taken from the oil reservoirs.
Isolating microorganisms producing biosurfactants and/or organic acids, polymers, gases and using hydrocarbons under low water activity.
Isolating microorganisms producing the above chemicals under reservoir conditions from hydrocarbons or cheap feedstocks.
To genetically or physiologically manipulate useful microorganisms adapted to be active under the reservoir conditions.

13. Exploitation of Deep fields
High Temperature ( > optimum less bacteria growth) (85C is well known, but is possible).
High Pressure (careful consideration must be given to the effects of pressure on growth rate and yield as they might result in delays in the bacterial release of oil or possibly even lowered bacterial activity to the point where expected benefits are not obtained at all.)
High Salinity (high NaCl concentration will inhibits the growing of bacteria, so better use Halophiles at high NaCl ppm).

14. Plugging of Formations (due to bacteria metabolism and their products)
Down-side of MEOR
Plugging of Formations (due to bacteria metabolism and their products)
- plug porous rocks causing reduced permeability.
Degradation of Oil in Reservoir (CH4 diffusion from oil)
Bacterial Corrosion (sulphate-reducing bacteria)
Souring (H2S)
Insufficient Nutrition for Bacteria.

15. MEOR- The Hard Part!
Process development, scale-up, field implementation….

16. Sustainable Development and MEOR
MEOR reduces or eliminates the need to use harsh chemicals during oil drilling
It is an environmentally compatible method of carrying out tertiary oil recovery.
MEOR will become increasingly economically feasible as genetic engineering develops more effective microbial bacteria that may subsist on inexpensive and abundant nutrients.
Methods for developing and growing MEOR bacteria are improving, thereby lowering production costs and making it a more attractive alternative to traditional chemical methods of tertiary oil recovery.

17. Conclusions I Key potential advantage of MEOR
–ability to use in situ carbon source
Key disadvantages of MEOR
Likely microbial performance constraints
Poor lab, field performance relative to peers (other chemical EOR)
Preferred MEOR option
Profile modification via biomass
Simpler, esp. with indigenous microbes
Compared to waterflood -Small incremental cost; Marginal increase in difficulty

18. Conclusions II
While the research on MEOR mechanisms is still not adequate and the success rate is still not high enough to increase heavy oil recovery on a large scale, at today’s oil prices this is a promising technology which offers major R&D and commercial opportunities.