Microbial Prospection For Oil & Gas

1. In the Name of God

2. Microbial Prospection For Oil & Gas (MPOG)

3. Presentation outline • Introduction • Basis of MPOG • Material & Method • Applications • Advantages and Disadvantages • Success Rate

4. Introduction • The microbiologist Mogilewskii (1940) in the U.S.S.R. and Taggart (1941) and Blau (1942) in the United States described the use of hydrocarbon-oxidizing bacteria (HCO) as an indicator for oil and gas fields in the deeper subsurface. • Microbial Prospection for Oil and Gas (MPOG) was developed in Germany and has been used there as a stand-alone technique for detecting microseepagessince 1961. • The technique has also been used offshore in the North Sea since 1995.

6. oil and gas fields also build up microseepages at the surface, and these microseepagesare detectable using a variety of analytical techniques that have been developed in the past 70 years. • These changes form the basis for other surface exploration techniques, such as soil carbonate methods, magnetic, electrical methods, radioactivity and satellite-based methods etc. • Microbial prospecting method for hydrocarbon research and exploration is based on the premise that the light gaseous hydrocarbons (C1-C8)migrate upward from subsurface petroleum accumulations and are utilized by a variety of microorganisms present in the sub-soil ecosystem.

7. All reservoir seals, even shales and salts, can be penetrated by these exceptional gases. • The methane, ethane, propane, and butane-oxidizing bacteria exclusively use these gases as carbon source for their metabolic activities and growth. • Bacteria are ubiquitous in the environment but will concentrate (enriched) where a food source is available. • These activities lead to the development of near-surface oxidation-reduction zones that favor the formation of the variety of hydrocarbon-induced chemical and mineralogical changes.

8. Microbial anomalies have been proved to be reliable indicators of oil and gas in the sub-surface in many parts of the world. • This method can be integrated with geological, geochemical andgeophysical methods, thereby reducing the drilling risks and achieving higher success in petroleum exploration.

9. Microbiological Basis Physicochemical Basis

10. Basis of MPOG Physicochemical Basis The physical state of hydrocarbons during transport Vertical migration mechanisms Micelles Diffusion Effusion Gaseous phase True solution water displacement by ascending gas bubbles Oil phase Aqueous Micro Fractures

11. Microbiological Basis High Adaptability Adaptation period hydrocarbon-oxidizing bacteria Types of bacteria in connection with MPOG

12. High Adaptability • The ubiquitous distribution of bacteria and their exceptionally high adaptability to grow on different nutrient sources form the basis of microbial prospection. Hydrocarbon-oxidizing bacteria, like all other types of bacteria, are found all over the world. • Wherever life can exist and small traces of hydrocarbons occur during a period of several years in the soil, there is a significant occurrence of populations of specialized bacteria. • Their specialization makes it possible for bacteria to be allocated to various groups, according to biochemical capabilities.

13. Types of bacteria in connection with MPOG • In terms of investigations in connection with microbial hydrocarbon prospection, two groups are relevant: • methane-oxidizing bacteria • hydrocarbon-oxidizing bacteria

14. methane-oxidizing bacteria • particularly specialized in the use of C1-compounds. • They are not able to consume sugar (glucose) or short-chain hydrocarbons. • The methane-oxidizing bacteria are therefore grouped in the category of methylotrophic organisms. • Microbial methane oxidation startswith an activation of methane by methane-oxygenase,and leadstomethanol andthen to formaldehyde. • Because of the high specialization of these bacteria, the geochemical methods allow methane oxidizers to be isolated from all other bacteria and analyzed. • A significantly increased activity and cell number of methane oxidizing bacteria represents an indication for methane occurrence in soil samples. • using methane-oxidizing bacteria for gas exploration.

15. hydrocarbon-oxidizing bacteria • Uses short-chain hydrocarbons (C2–C8) as an energy source. • not able to metabolize methane. • The degradation of the alkanes occurs by terminal oxidation by means of mono-oxygenase and by β-oxidation to acetyl-CoA, which is the initial substance in several biochemical reactions.

16. Adaptation period hydrocarbon-oxidizing bacteria • The organisms can grow on short-chain hydrocarbons in the laboratory, the production of essential proteins and enzymes in the bacterial cells requires an adaptation period of several days,because does not exist short-chain hydrocarbons in environment. • The organisms with inactive hydrocarbon-degradation potential are described as “optional.” • In comparison, other bacteria in the laboratory grow without any significantdelay on ethane, propane, and butane, because they are adapted to do so in their natural surroundings. • This group is referred to here as “obligate.”

17. Detection of active bacteria which oxidize n-alkanes with chain lengths of 2 to 8 carbon atoms without any adaptation period indicates the existence of oil signatures in the area investigated.

18. Material & Method Sampling Techniques Culture method Plotting of Bacterial Anomaly

19. Sampling Techniques • The sampling is important since the validity of the test results depend largely on the manner in which the samples are taken. • In reconnaissance surveys the samples were collected along the existing roads, usually in an interval of 3 to 5 km. • The grid surveys are designed based on the size of the survey area; usually the samples were collected in a close interval of 200 m 200 m or 500 m500 m.

20. The samples were sealed in the plastic bags with their sample number and Global Positioning System (GPS) locations marked. • The soil samples were collected using hollow metal pipe by manual hammering. • The soil samples of about 100 gm each were collected in pre-sterilized polythene bags under aseptic conditions from a depth of about 0.5 to 1 m, the samples were transported to the laboratory and stored at 2°C to 4°C till analysis.

21. Culture Method • Isolation of RNA • Duplication of the RNA • Quantification of PCR Band

22. Plotting of Bacterial Anomaly • Standard hydrocarbon bacterial cultures need to obtain form any culture collection centre, such as American type culture collection centre (ATCC) or Microbialtype culture collection centre (MTCC). • The results of hydrocarbon oxidizing bacterial population are plotted on the surveyed map. • More than background ========= Positive prospects • Less than background ========= Negative prospects

23. Applications • In areas that have not yet been investigated geophysically, this technique can be applied as wildcat prospection. The subsequent seismic and geologic investigations thus could be concentrated on favorable areas. • In regions where subsurface structural data already exist, the sampling-station interval can be reduced to create a more detailed picture of the hydrocarbon anomalies. • Reservoir characterization.

24. Advantages and Disadvantages • Sample taking is simple and environmentally friendly • The technique is unaffected by external disturbance factors • The technique is not influenced by fractures, overlying salt or other geological structures • There are no halo effects - unlike other surface prospection method • Effective also in difficult terrain Advantages

25. Reliable results are obtained even for structures having a complex geological formation • Areas of application include both existing onshore (permanently frozen, continental and desert soil) and offshore sites • Establishing a clear distinction between oil reservoirs, gas reservoirs and oil bearing structures with a gas cap is generally fully feasible • Reliable differentiation between hydrocarbon prospective and non-prospective areas • High Success Rate to wildcat prospection

26. Disadvantages • cannot predict the depth of the reservoir, because it is a surface prospecting method and directly depends of the migration of light hydrocarbon gases from oil and gas reservoirs • cannot differentiate between biogenic and thermogenicgases

27. Success Rate 90% 96% 81% Exploration Wells

28. REFERENCES • Rasheed, M., et al. (2015). "Application of geo-microbial prospecting method for finding oil and gas reservoirs." Frontiers of earth science 9(1): 40-50 • Zhang, F., et al. (2010). "Molecular biologic techniques applied to the microbial prospecting of oil and gas in the Ban 876 gas and oil field in China." Applied microbiology and biotechnology 86(4): 1183-1194 • Wagner, M., et al. (2002). "AAPG Studies in Geology No. 48/SEG Geophysical References Series No. 11, Chapter 19: Case Histories of Microbial Prospection for Oil and Gas, Onshore and Offshore in Northwest Europe."

29. THANKS FOR YOUR ATTENTION