Among various microbes, acid producing and sulfate reducing bacteria induce
corrosion in pipeline, while SRB create problem of souring. Growth of microbial
biomass leads to well clogging due to biofilm formation, and subsequently inhibits
the gas production. For better control of microbial growth, prior investigation of
microbe types and concentration, carbon sources, nitrogen sources, electron
acceptors, and growth limiting factors is required. The next generation sequencing
tool is frequently used for knowing such microbial community composition in
hydraulic fracturing fluids.
6.8
Conclusion
In oil field setup diverse microbial communities are present. In these microbial
communities mainly, sulfate reducing bacteria, nitrate reducing bacteria, fermentative bacteria, iron reducing bacteria, iron oxidizing bacteria, and methanogens are
dominated. Factors such as downhole reservoir temperature and pressure are extreme
for the oil field microbial communities. In oil field system, oil organics are used as a
carbon source, while inorganic compounds (such as sulfate, nitrate, and iron) are
used as electron acceptor. In an oil reservoir, during oil biodegradation firstly higher
oil components are converted into lower oil components by fermentative bacteria.
These lower components are further used by sulfate or nitrate reducing bacteria. At
the last stage, methanogens use one or two carbon compounds and converted into
methane. Thus, due to microbial growth in oil field system, field operators face
various problems such as microbial souring and biocorrosion, etc. The SRB is
responsible for microbial souring in oil reservoir. To inhibit microbial souring
various measures are taken by oil industries. The biotechnological approaches
have great potential to control souring. Application of metabolic inhibitors and
bacteriophage are the latest novel techniques to control souring with least environment impact and specifically target to problematic microbes only. Other than
souring, different biotechnological approaches are applied in controlling microbial
induced corrosion, EOR process, biodesulfurization, tailing ponds, and shale gas
production. In mEOR, different microbial and plant origin biopolymers are applied
to enhance oil production. Nanofluid with polymer is also applied as a novel strategy
for the EOR process. For biodesulfurization, microbes and immobilized microbial
cells are applied. For improving efficiency of desulfurization, recombinant DNA
technology is becoming a good option. For reclamation of tailing pond affected land,
aerobic treatment, biodegradation of oil components, and microbial sequestration are
used. For upgradation of heavy oil, microbes can be used which utilize heavy oil
components and convert it into lighter oil components. In shale gas fields, microbial
souring, biocorrosion, and degradation of fracturing fluids are major problems.
These problems are addressed by biocide injection in fracturing fluids. But prior to
uses of biocide, microbial community composition should be known for the designing of appropriate control strategy.
6 Application of Biotechnology in Oil and Gas Industries
129
corrosion in pipeline, while SRB create problem of souring. Growth of microbial
biomass leads to well clogging due to biofilm formation, and subsequently inhibits
the gas production. For better control of microbial growth, prior investigation of
microbe types and concentration, carbon sources, nitrogen sources, electron
acceptors, and growth limiting factors is required. The next generation sequencing
tool is frequently used for knowing such microbial community composition in
hydraulic fracturing fluids.
6.8
Conclusion
In oil field setup diverse microbial communities are present. In these microbial
communities mainly, sulfate reducing bacteria, nitrate reducing bacteria, fermentative bacteria, iron reducing bacteria, iron oxidizing bacteria, and methanogens are
dominated. Factors such as downhole reservoir temperature and pressure are extreme
for the oil field microbial communities. In oil field system, oil organics are used as a
carbon source, while inorganic compounds (such as sulfate, nitrate, and iron) are
used as electron acceptor. In an oil reservoir, during oil biodegradation firstly higher
oil components are converted into lower oil components by fermentative bacteria.
These lower components are further used by sulfate or nitrate reducing bacteria. At
the last stage, methanogens use one or two carbon compounds and converted into
methane. Thus, due to microbial growth in oil field system, field operators face
various problems such as microbial souring and biocorrosion, etc. The SRB is
responsible for microbial souring in oil reservoir. To inhibit microbial souring
various measures are taken by oil industries. The biotechnological approaches
have great potential to control souring. Application of metabolic inhibitors and
bacteriophage are the latest novel techniques to control souring with least environment impact and specifically target to problematic microbes only. Other than
souring, different biotechnological approaches are applied in controlling microbial
induced corrosion, EOR process, biodesulfurization, tailing ponds, and shale gas
production. In mEOR, different microbial and plant origin biopolymers are applied
to enhance oil production. Nanofluid with polymer is also applied as a novel strategy
for the EOR process. For biodesulfurization, microbes and immobilized microbial
cells are applied. For improving efficiency of desulfurization, recombinant DNA
technology is becoming a good option. For reclamation of tailing pond affected land,
aerobic treatment, biodegradation of oil components, and microbial sequestration are
used. For upgradation of heavy oil, microbes can be used which utilize heavy oil
components and convert it into lighter oil components. In shale gas fields, microbial
souring, biocorrosion, and degradation of fracturing fluids are major problems.
These problems are addressed by biocide injection in fracturing fluids. But prior to
uses of biocide, microbial community composition should be known for the designing of appropriate control strategy.
6 Application of Biotechnology in Oil and Gas Industries
129