Petrol

Use of QGO-M kits to monitor the microbiological activity in the petroleum industry (« Upstream, Midstream and Downstream activities »)

Microbial contaminations in the petroleum industry have engendered and continue to engender millions of Euros in damage and operational costs.
Nowadays, the Aqua-tools ATP-metry kit enables, within 3 minutes, to immediately measure the microbial contagion using the Adenosine Triphosphate (ATP) parameter.
With an immediate result, the industrial can react quickly in front of an operational drift by setting up preventive treatments. He can also apply fewer continuous treatments (biocide, bio-dispersing treatments) by real quantification of the microbial contamination in order to economize chemical products and money.

Origins of microbial contamination in petroleum

In practice microbial contamination in petroleum can have different origins:

1. Entry of air - tank at the stage of balancing the air pressure because the atmosphere contains a multitude of water droplets transporting microorganisms (“Upstream”)
2. Transport -  there is often sufficient water in the bottom of large storage tanks and even in the fuel tanks of road vehicles such as trucks and buses for some microbial growth to occur  (“Midstream”)
3. Water in the network – water may contain a very high concentration of microorganisms (pipe line…)
4. Water injection via the wells which contain a high water contamination and bacteria.

Consequences of a biological deterioration

The consequences of a biological deterioration in oil industry can be distinguished in 3 groups:

1. Microorganisms attack hydrocarbon and non-hydrocarbon molecules involving a change of the characteristics and chemical properties of the crude oil
2. Microorganisms grow up at the interface of oil and water or in the biofilm and produce biosulfates, detergent molecules and H2S molecules.
3. Weak molecular weight secretions from microorganisms react with crude oil and accelerate the formation of particles which make fuel more corrosive.

The principal disorders caused by a bacterial proliferation result in:

1. Fouling: by slimes produced by bacteria, yeasts and/or moulds which can cause severe filter plugging, blocking of fuel lines and injectors and consequently then cause excessive wear and failure of engines and system components. Fuel fouled by microbial slimes can fail particulate specifications.
2. Corrosion: microbial growth in fuel tanks and fuel systems can result in rapid and severe corrosion. For example occasional problems occur in aircraft wing tanks due to the growth of moulds and also yeasts and bacteria which produce organic acids stimulating corrosion by creating oxygen gradients which enhance electrochemical corrosion cells.
   • In steel tanks, growth of Sulphate Reducing Bacteria (SRB) in water and sludge in the bottoms of tanks can cause pitting corrosion.
   • Growth of Sulphate Reducing Bacteria (SRB) in fuel tanks can also cause sulphide spoilage of fuels. The fuel becomes corrosive and will fail sulphide limit specifications.
3. Microbial surfactants can stimulate the suspension of water in fuel causing it to become cloudy and causing failure of fuel water separators

4. When the tank content is disturbed, for example when the tank is refilled, the microbes become suspended in the bulk fuel where they cause fouling and may pass through the distribution chain to contaminate facilities downstream (motors…)

Although microbiologists used to think that sulfate reducing bacteria (SRB) were the only microbes involved in microbial influenced corrosion (MIC), we now know that, while SRB play a role in MIC, they are not unique.  Non-SRB (such as acid-producing, iron-reducing, and slime-forming bacteria) contribute to MIC in a variety of ways.  The two most common are the production of biofilm (causing chemical and electro-potential gradients between surfaces that are covered with biofilm and those that are not), and production of weak organic acids which react with chloride, sulfate, nitrate and nitrite ions to form organic salts and strong inorganic acids (hydrochloric, sulfuric, nitric and nitrous acids) within biofilms; particularly within MIC pits.

Benefits of QGO-M™ kit for surveillance of biological contamination of oil

Aqua-tools’ 2^nd generation ATP monitoring test kits can be used as a preventive tool, an alarm, enabling fast detection of disorders and microbial proliferation in all segments of oil industry:

1. Upstream: extraction, exploration of the crude oil, pipe line, contamination of water…
2. Downstream: pipe line towards the refineries, production of gasoil, lubricants, kerosene, hydraulic liquids…
3. Midstream: pipe line, reserve, tank of storage, gasoline distributors…

QGO-M kit has the advantage to be more sensitive and in the same time of providing an answer in few minutes whereas several days are necessary for the culture test. Additionally, QGO-M kits measure all living microorganisms, cultivable or non-cultivable.
QGO-M kit gives multiple possibilities of uses for the petroleum industry; it enables to:

1. Measure in real time the concentration of microorganisms in the samples and give an immediate indication on contamination levels. Monitor the microbial growth in water, in biofilm and deposits.
2.  Prevent microbial corrosion and protect material from breakdowns. Early detect the degradation of oil storage and transport facilities.
3. Carry out in real time quality controls, in the fuel, in the lines of lubricant, in the reserves and in the distribution network...
4. Monitor the microbial contamination from the raw material (crude oil) to the finished product (fuel…).  Identify the origins of microbial contamination - raw materials (crude oil, fuel…); distribution and production equipments (extraction and distribution pipes). Localize critical zones for bacteria proliferation in production, distribution and storage systems.

Validate the effectiveness of the treatments on cultivable and non cultivable microorganisms, optimize the concentration, the frequency, and injection points of biocides, and monitor treatment effectiveness in water and oil phase.
The ATP-metry, a non specific technique, enables decreasing of SRB culture test frequency because:

1. If ATP is low that means that the installation is secure regarding SRB contamination
2. If ATP is high, prepare SRB dilution bottles for specific tests and implement immediate corrective actions to solve the microbial problem.