Produced Water Treatment

UV Disinfection of Produced Water 

With environmental regulations becoming more stringent, and the link between re-injected water quality and operational costs becoming clear to operators, investing early in advanced water treatment solutions for produced water for both reinjection applications and environmental discharges is now a top priority for operators worldwideatg UV Technology have provided a number of specialist UV packages for the disinfection of Produced Water in order to reduce microorganisms such as SRB’s (Sulphate Reducing Bacteria), Acid Producing Bacteria and Slime Forming Bacteria, that if left untreated, pose a range of negative consequences including: -

  • Souring the well with hydrogen sulphide gas H2S
  • Microbiological induced corrosion
  • Loss of fluid stability during injection
  • Plugging of the well
  • Damage of equipment and components (e.g. RO membranes, filters)

Traditionally large volumes of biocide such as Glutaraldehyde and THPS have been used to chemically dose Produced Water to control bacterial growth before reinjection, however the rising costs of chemicals, handling and offshore storage concerns plus an appetite by operators to reduce the amount of chemicals added to the process has seen operators turn to UV treatment as an alternative solution.    

Working with a number of leading oil and gas operators, atg UV Technology have performed a number of research studies and pilot trials to prove the effectiveness of UV treatment for the biological control of produced water, and have successfully supplied a vast number of UV treatment packages to the field.    

By using UV treatment as a primary solution for reducing bacteria, operators can significantly reduce the required volumes of biocides from the process typically by 90%, only requiring a small residual to protect the pipework from re-contamination upstream of the UV package.  In some cases, operators have been able to switch from aggressive biocides such as Glutaraldehyde to less hazardous options such as chlorine. 

With the reduction in biocide use and the subsequent reduction in offshore transportation, handling and storage, UV treatment offers a green, environmentally friendly solution that offers to significantly improve the operational costs of produced water treatment operations. 

 

Advanced Oxidation & OSPAR Chemicals of Priority Action

atg UV Technology have recently patented a unique Advanced Oxidation Process known as Keratox for the treatment and removal of organic and chemical contaminants from Produced Water. 

Utilising atg UV Technology’s UV treatment systems in combination with a unique Titanium Dioxide (Tio2) catalyst, the Keratox advanced oxidation solution can be used to target and remove contaminants detailed on the OSPAR list of chemicals for priority action such as Polyaromatic hydrocarbons, BTEX compounds and Phenols.   

When UV light reacts with the Ti02 catalyst, a highly oxidative compound species known as Hydroxyl Radicals are created.  The Hydroxyl Radicals effectively break apart all naturally occurring and added organic and chemical contaminants into their base components of C02 and H20.  Whilst extremely reactive, Hydroxyl Radicals have a very short life, and pose no environmental risks.

Unlike traditional advanced oxidation techniques that require chemical dosing with catalytic agents such as hydrogen peroxide or ozone, the Keratox solution provides a fixed and natural catalyst that is not consumed by the process, and therefore has a significant advantage in lowering the operational costs when compared to other technology processes such as membrane filtration.

Benefits of Keratox

  • Simple to use ‘turn-key’ onsite solution
  • Very low operation & maintenance requirements
  • Ultra compact footprint & low weight solution
  • Eliminates chemical transportation & storage
  • Environmentally friendly, green technology
  • Safe, low risk technology to operate 
  • Reduced OPEX costs compared to other available technologies

The use of the Keratox advanced oxidation technology is perfectly suited as a final polishing technique to remove final concentrations of contaminants, allowing produced water to be treated to a significantly higher standard, at a reduced cost.