Microbes- Friend or Foe

Figure 1.

Source. Microbes.

Microbes can be used as method of EOR however the area lacks research and this method has not been implemented yet but it does certainly have a great potential. It is a bio-based approach to improve the efficiency of oil recovery and allows to recover more oil from any reservoir like any other enhanced oil extraction technique. There are tow main strategies employed in Microbial Enhanced Oil Recovery (MEOR). Firstly nutrients (microbes) are injected or the activity of indigenous bacteria already thriving in the oil field is encouraged. And secondly, injecting specific bacteria into the reservoir together with a nutrient solution. (European Science Foundation,2010). Once injected, microbes produce harmless by-products such as slippery natural substances or gases once they interact with the oil making the oil more volatile and enabling it to come to the surface. (IPACT (International Journal of ChemTech Research),2013).

The research is currently focused to make MEOR technically and economically feasible as well as environmentally friendly or at least not harmful. Potentially some papers argue that this method has no environmental implication if applied in an appropriate way. Moreover this is believed to be a cheap process thus very economically sustainable in terms of oil recovery. Below are the potential advantages and disadvantages of using MEOR.

Advantages:

• ·      Both microbes and nutrients that require injection are cheap.
• ·      Increase oil production.
• ·      Existing infrastructure requires only slight adjustments.
• ·      Easy application of the method.
• ·      Less expensive set up than other EOR methods.
• ·      Low energy requirement for microbes to produce MEOR agents thus environmentally friendly as the method does not require prior combustion of fossil fuels to obtain energy to make the system work.
• ·      Potentially more efficient than other EOR when applied to carbonate oil reservoirs.
• ·      Microbial activity increases with microbial growth thus once injected, little further action has to be taken. Potentially the opposite of other EOR when constant additional action is required to keep the oil coming from the reservoir.
• ·      Cellular products are biodegradable thus it is environmentally friendly.

Disadvantages:

•      As any living thing, microbes require oxygen for aerobic processes such as aerobic respiration to allow cell growth. Oxygen is a corrosive agent for non-resistant topside infrastructure and pipes used.
• ·      Anaerobic MEOR is also not ideal as it requires large amount of sugar thus making the application of method more difficult due to costs especially in offshore fields where major transportation costs become involved too.
• ·      Exogenous microbes require facilities for their cultivation.
• ·      Whilst indigenous microbes require standardized frameworks and research facilities for evaluating microbial activities.
• ·      Microbial growth is only favored under certain conditions thus this method could be implemented only in specific reservoirs.
• ·      Microbial processes require preceding removal of debris and mud potentially blocking the channels where oil flows, which could potentially prove expensive.
• ·      Water floods may be required to increase microbial activity.
• ·      And finally and most importantly, microbes are a living thing that have not had an awful research done to them with regards to MEOR so a potential biological catastrophe could be created if microbial growth gets out of control.

Thus whilst the method has a lot of advantages the ecophysiology of microbial communities thriving in oil reservoirs lacks knowledge and requires a lot of research before the method can be implemented. There is currently a poor critical evaluation of the physical and biochemical mechanisms controlling microbial response to the hydrocarbon substrate and their mobility thus could lead to major harm to be caused to humans if the process gets out of hand as previously mentioned- a biological disaster. The real environmental impact that MEOR would cause has also not been assessed and thus remains a mystery. Furthermore the life cycle of said microbes under the reservoir conditions and their ability to multiply is also unknown. So whilst this method seems attractive, it also seems very daunting and scary if things were to go wrong. Considering it uses living things, there could be no return and it could prove irreversible once the microbes have been injected into the reservoir so significant amounts of research should be done regarding the safety of this method before implementation. Furthermore such a method would require a lot of convincing for the public as people generally get very freaked out and scared when hearing the word “microbes” as obviously it is associated with illnesses and all the negative things one could experience. Unless people understand biology, they are often unaware of the positive impacts and functions of microbes even such little things as enzymes that are used in our stomach to help digestion, which are also microbes. However the public will obviously have to be considered before anything such as this new technology is implemented.