1. Microbial Enhanced Oil Recovery
Microbial Process Technology
Elda Renedo Gil
Abdelrahman Abdelkader
Ihab Hashem
Jesse Verlinden

2. Overview Introduction Technology
Economical, ecological and social assessment
Conclusion
Highlights

3. Introduction Oil extraction from well
Primary recovery: natural mechanisms (5-10%)
Natural gas expansion
Secondary recovery: fluïd injection (25-30%)
Water or natural gas
circa 65% not recovered
Let us have a look which methods are available for oil extraction from a well.
The first methods applied to extract oil from a new oil field are part of the primary recovery.
They use natural mechanisms for oil extraction, which means that the underground pressure is sufficient to force the oil to the surface.
The major natural mechanism is the expansion of the natural gas present in an oil field. As pressure decrease due to depletion, dissolved gas in the oil evaporates and raise the pressure, and so supplying new driving forces. Also some minor effects result from water expansion and gravity drainage.
In the primary recovery step, only 5-10% of the oil present in an oil field can be recovered.
After this first step, secondary recovery is necessary to extract more oil from the oil field.
They rely on the supply of external energy into the reservoir in the form of injecting fluids to increase reservoir pressure,
hence replacing or increasing the natural reservoir drive with an artificial drive.
Water and natural gas are injected to increase the pressure in the oil field.
Secondary recovery is able to extract an additional 25-30% of oil.
After Secondary recovery, still 65% of the oil is not recovered!

4. Introduction Primary recovery: natural mechanisms (5-10%)
Secondary recovery: fluïd injection (25-30%)
Tertiary or enhanced oil recovery (EOR):
Gas injection
Thermal recovery (TEOR)
Chemical injection
Alkaline, surfactant, polymer and MICRO-ORGANISMS
MEOR Extra 20-30% recovery!
That is why tertiary or enhanced oil recovery technologies are necessary, knowing that oil fields are rare and fossil fuel is our major energy source.
3 major techniques are available.
With gas injection, carbon dioxide, natural gas or nitrogen gas is injected, with the purpose of reducing
the interfacial tension between oil and water, and to reduce the viscosity of the oil, to facilitate flow.
With thermal injection, heat is supplied to reduce the viscosity and partly vaporize the oil. The heat is mostly supplied by steam injection.
Lastly, injection of several mostly diluted chemicals is used to reduce surface tension and viscosity. Alkaline and polymer solutions, surfactants but also micro-organisms are injected.
The injection of micro organisms is used in microbial enhanced oil recovery and we will discuss this technology during this presentation.
The enhance oil recovery methods recover an additional 20-30% of oil.
We will focus on the enhanced oil recovery by chemical injection of micro-organisms.

5. Technology

6. Technology Nature of microorganisms
halophile, barophile, thermophile microbial strains
Source of microorganisms
Two major ways:
Selective plugging
Metabolites production
Hydrocarbon-utilizing & non-pathogenic
Halophile = salinity
One of the challenges is to isolate these strains
Mostly naturally occurring in the reservoir & genetically engineered
Need nutrients mainly molasses  cheap

7. A. Selective plugging
Microorganisms plug the higher permeable path to get the oil from other places
Water with nutrients and microorganism or already exist

8. A. Selective plugging
adapted from

9. B. Metabolites production
Gases, solvents and acids
Re-pressurizing
Reduce oil viscosity
Carbonate rock dissolution
Gases: CH4 CO2 H2
Acids: Acetic

10. B. Metabolites production
Biopolymers and biofilms
Plugging effect: dead bacteria vs. polysaccharides
More efficient than the bacteria bodies
Metabolites adhesion force

11. B. Metabolites production
Biosurfactants
Interfacial tension
Wettability
Surfactants do what surfactants do!

12. B. Metabolites production
Biosurfactants
Interfacial tension
Wettability

13. Economical, ecological and social assessment.

14. Economical feasibility
Increase in the production of oil
Higher economic lifetime of the wells.
Reduction in water cut achieved
Low operating cost
Minor modifications to existing field facilities.
Profitable and economically feasible
MEOR PROCESSES WILL LEAD TO AN INCREASE IN THE PRODUCTION OF OIL. Some fields trials reported an increase of 45.6%. Therefore incrising the lifetime of a well.
A significant reduction in water cut was observed (% of water in the oil flow throught pipes)
It is a low cost process: does not consume large amounts of energy and it does not depend on the oil price
It can be implemented easily with minor modifications to existing field facilities.
It has proven to be profitable and economically feasible

15. Economical feasibility
Drawbacks:
Need of a better understanding of the MEOR processes
Scaling up
Not enough field applications
However , there is a need of a better understanding of the MEOR processes and mechanisms behind them, from an engineering point of view. A Better knowledge of then economics, applicability and performance is the key to further improve the process efficiency.
It is as well difficult to scale up, and to translate the laboratory results to real-time oil field setups.
Because of the these reasons there aren’t enough fields trials or applications yet.

16. Ecological impact Safe to handle and pose no threat Eco-friendly
Toxicity test; Long term effects
Lack of understanding of the mechanism
Difficult to extrapolate results
Studies reported MEOR processes as safe to handle and pose no threat to the environment, plants, animals or human beings (these is based on tests conducted by public health laboratories)
It is an environmentally friendly petroleum recovery process
Still it is compulsory to perform a toxicity test for any organism to be used in the field for MEOR to assure the safety of involved parties. And the main concern are the long term effects, which are not well known, due to inconsistent technical performance( haven’t being running for long enough time) and lack of understanding of the mechanism of oil recovery
Another aspect is the Difficulty of extrapolating the results from one microbial field trial to other reservoirs as each reservoir has its unique properties and microbial population for indigenous MEOR cases

17. Sociological impact of the process
Environmental concerns
Insufficient knowledge of the process mechanism
Consequences of pumping bacteria to ground

18. Source: survey by the university of Lethbridge, Alberta, Canada

19. Source: survey by the university of Lethbridge, Alberta, Canada

20. Conclusion

21. Conclusion Need for tertairy oil recovery methods
MEOR is promising technology on both the economical and environmental front
But more research is needed...
There is an economic need for tertiary oil recovery methods.
Using MEOR results in a signifigant increase in oil production and higher economic life of the well.
MEOR has a minimal ecological impact and poses no threat to the environment. Long term effects!
Need for more studies to understand the mechanisms of oil recovery and scaling up.
Need for communicating the results to society.

22. Highlights

23. Highlights
Traditional oil recovery methods can only produce 35% of the well capacity
Tertiary oil recovery can get an additional 20-30%
MEOR is a technology that manipulates microbial environment in an oil reservoir in order to improve the oil recovery from porous media.
Microorganisms used should be hydrocarbon-utilizing and non-pathogenic.
Microorganisms used are a mixture of naturally occurring in the well and genetically engineered microorganisms.

24. Highlights
Oil recovery occurs through two main mechanisms: selective plugging and via metabolite production.
In selective plugging, microorganisms plug the higher permeable paths forcing water to residual oil paths.
Metabolites produced by bacterial action can lead to a reduction in oil viscosity and carbonate rock dissolution.
The process has low operating costs and can be implemented in current plants.
Economically feasible and pose no threats to environment, however not enough field applications.

25. Thank you

26. References
R. Sen, “Biotechnology in petroleum recovery: The microbial EOR,” Prog. Energy Combust. Sci., vol. 34, no. 6, pp. 714–724, 2008.
L. R. Brown, “Microbial enhanced oil recovery (MEOR),” Curr. Opin. Microbiol., vol. 13, no. 3, pp. 316–320, 2010.
I. Lazar, I. G. Petrisor, and T. F. Yen, “Microbial Enhanced Oil Recovery (MEOR),” Pet. Sci. Technol., vol. 25, no. 11, pp. 1353–1366, 2007.
Sen, R. (2008). Biotechnology in petroleum recovery: The microbial EOR. Progress in Energy and Combustion Science, 34(6), 714–724.
Maure A, Saldaña AA, Juarez AR.(2005) Biotechnology applications to EOR in Talara off-shore oil fields, Northwest Peru; SPE Paper no
Al-Sulaimani, H., Joshi, S., Al-Wahaibi, Y., Al-Bahry, S., Elshafie, a., & Al-Bemani, a. (2011). Microbial biotechnology for enhancing oil recovery : Current developments and future prospects. Biotechnology, Bioinformatics and Bioengineering, 1(2), 147–158.