ETS is a world leader in both design and application with the use of UV technology in the oilfield sector.
This sector demands highly ruggedized designs, and a particular understanding of the environment in which the machines will be used. Both conventional oil recovery and now the access to unconventional oil and gas require the use of large amounts of water and most often this water will contain microbial contaminants. Some of these microbes, such as the SRB species, will cause corrosion, and the reservoir to become soured. Typically the chamber will be manufactured from 316L Stainless steel, however for high corrosion potential applications, ETS can manufacture from Duplex 254 steels that are specifically enhanced to prevent corrosion.
Varieties of species are able to survive in oxygen rich (aerobic) water, or in the oxygen starved (anaerobic) environments. Aerobic bacteria can convert iron from the ferrous (Fe2+) to the ferric (Fe3+) state, and produce ferric hydroxide (Fe [OH]3), which is highly insoluble and causes formation damage. Iron oxidizing bacteria can become a slime forming species that will form mats of high-density slime that will begin to cover surfaces. If allowed into the well, they shield corrosion forming bacteria colonies from chemical bactericides and plug the pores of the matrix holding the oil.
Anaerobic species such as Sulfate Reducing Bacteria, (SRB's) can convert sulfate or sulfite that is naturally occurring, or present in a variety of drilling muds into hydrogen sulfite (H2S). When combined with iron, iron sulfide is formed which is a scale that is very costly to remove. In addition, SRB species can cause pitting corrosion of steel, and elevated H2S increases the corrosiveness of the water, which increases the possibility of hydrogen blistering, sulfide stress cracking, and can lead to costly sweetening of sour oil.
To protect against SRB's, ETS UV systems are usually installed following filtration of the water to remove suspended solids. As filters can often be a source of microbial growth, ETS UV equipment is best located post to filtration.