The oil exploration and production process involves a
series of chemical and physical processes that occur continuously and
their effective management can mean the difference between success and
failure.
Antifoamers
Foaming occurs in crude oil formations due to various
factors such as pressure changes, occurrence of contaminants and
presence of bore mud, sand deposits and wax. Foam in the crude oil can
lead to poor well production, cavitation problems in pump, poor
separation, loss in pumping efficiency, and irregular fluid flow.
Antifoamers combine with the nucleation sites of the contaminants and
reduce foam generation.
Asphaltene control
Asphaltenes occur as stable colloidal substances in
the crude oil. They have high polarity and their precipitation occurs in
various aspects of production and transportation. They are caused by;
drops in pressure, fluctuating PH, unstable flow or shear flow and
presence of carbon dioxide. Asphaltenes cause formation of heavy
emulsions in the crude tanks, which eventually reduces recovery of oil
and blockage of pipelines. They are managed by use of asphaltene control
substances, which dissolve the asphaltene colloids as well as inhibit
asphaltene precipitation.
Biocides
Microbial contamination is bound to occur in various
stages of the oil production process and their presence can cause
interference in oil production process. Some bacteria in oil production
include;
- Slime producing sessile bacteria,
- Sulphate altering bacteria; causes contamination of the oil well leading blocked oil production ,and reduce water penetration in clearance wells.
It is important for oil producers to prevent
establishment of bacterial colonies and they are impossible to clear.
Biocides are important for checking the growth of these tough bacteria
and ensure no biofilms are formed.
Corrosion Inhibitors
Corrosion is one of the biggest problems in oil
production and must be managed with appropriate caution. It leads to
deterioration of piping systems, storage tanks, and faster equipment
degradation. Corrosion inhibitors are critical in oil production to maintain equipment integrity as much as possible.
Drag Reducers
Development of high frictional pressure in the pipes
of crude oil leads to poor pumping efficiency and possible pump failure.
Drag reducers lessen the turbulence in the pipe thus enhancing the flow
rate and increasing the pumping efficiency.
Emulsion Breakers
When oil and water are forced to mix, emulsions
develop, which interfere with the crude pumping process. Emulsion
breakers target the boundary /interface between the oil and water and
create a strong film that prevents coalescing of the droplets to form
larger droplets and break the emulsion.
Hydrogen Sulphide Scavengers
Bacterial action of sulphate reduction causes
occurrence of hydrogen sulphide gas. This gas causes severe corrosion of
gas and crude pipes causing leakages and failure in production. This
process can be prevented by creation of an inhibiting layer using the
hydrogen-sulphide scavengers.
Hydration Inhibitors
Hydrates are chemical formations in the piping lines
that can grow as the reactions continue. They lead to formation of
hydrate plugs in the pipes leading to serious blockages. Hydrate
inhibitors are therefore used to chemically react with the hydrates and
cause them dissolve in solution.
Conclusion
The oil production process requires intensive
management of chemical reactions, which are many, and varied. If these
reactions are left unchecked, serious damages and downtimes are
experienced and can lead to drastic reduction in production. The most
serious reactions include corrosion, hydrate occurrence, emulsion
formations and friction reduction.
This article has been written by Govind Patel.
