Performance biocides for oil & gas fields, water treatment operations


With experience gained over the last 25 years, Solvay has secured a growing reputation as an innovative partner for service companies supporting the oil & gas field and water treatment industries.

Solvay’s biocide TOLCIDE® PS is targeted at a wide range of applications in oil & gas field and water treatment markets. TOLCIDE ® PS is a successful, fast-acting and powerful microbiocide, designed to eliminate bacteria from oilfield water flood operations or fracturing fluids in oil and gas reservoirs. It is also used in industrial water treatment installations.

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Fast Acting THPS Biocides

Tolcide® PS50A and Tolcide® PS70A are Solvay's 3rd generation THPS products with enhanced biocidal performance. These ready to use biocides combine both THPS and bio-penetrant to give superior microbial control.


Innovative TOLCIDE® PS A-series to combine performance and respect of the environment

Solvay’s TOLCIDE® PS A-SERIES range combines a biocide with a proprietary polymer that is both biodegradable and non-bioaccumulative. This non-foaming formulation, fully miscible with water and insoluble in oils,effective over a wide pH range, and easily analysed in the field, is approved for use in many environmentally sensitive areas of the world including the North Sea.

These biocide products help develop cost-effective and environmentally friendly solutions to maximize production from oil and gas reservoirs while reducing the overall consumption of chemicals by 20% (in Laboratory tests). 


Customer challenge

Reducing the overall consumption of biocides with eco-friendly solutions is a major challenge in the oilfield market.

Solvay has designed the TOLCIDE® PS A-SERIES biocide technology to solve problems of water clarity, scale formation, corrosion and microbiological fouling in the potable, industrial and waste water markets. Our customers enjoy the benefits of improved process efficiency and have the solutions to comply with the ever increasing legislative demands for environmental protection, conservation and improved human health in the use of water. 


Features and benefits of TOLCIDE® PS A-SERIES in Oilfield

Control reservoir souring

TOLCIDE®PS A-SERIES is the product of choice for use in water injection or (Produced Water Re-Injection) PWRI systems to help control reservoir souring and “sweeten” sour reservoirs. 


Control Microbial induced Corrosion (MIC) 

TOLCIDE®PS A SERIES is the product of choice for controlling MIC throughout oilfield water systems due to its ability to penetrate bio-films and control sessile bacteria and its ability to remove porous FeS deposits which accelerate pitting corrosion. 

  • Water injection
  • PWRI
  • Topsides
  • Flow lines (in conjunction with mechanical cleaners)


Facilitate demulsification in sour systems 

TOLCIDE®PS A-SERIES can supplement conventional demulsification processes by controlling particulate FeS build-up (both by controlling SRB & dissolving existing FeS particles). 

  • Improving separated water quality
  • Reducing overboard sheen  


Removal of “FeS” based deposits… including “Schmoo”

  • Improving injectivity 
  • Improving productivity  


Outperformance of standard THPS formulations

TOLCIDE®PS A SERIES has supplementary dispersion and scale control properties. 


Environmental profile

TOLCIDE®PS A SERIES has an outstanding rating as it is biodegradable and non-bioaccumulative, and on discharge rapidly breaks down to environmentally benign products.  The biocide formulation is halogen free. 



Biocides are regulated chemicals and their use can require specific permits and/or registrations. 


Oilfield applications

  • Water injection systems 
  • Top-side separation
  • Transmissions lines
  • Fracturing and stimulation fluids
  • Hydrostatic testing 


Industrial water Applications

  • Open evaporative cooling tower 
  • Re-circulating water systems
  • Process water treatment

THPS biocide used in fracturing applications

Tolcide® 4FRAC is a range of performance enhanced THPS products specifically designed to deliver added value solutions to microbial problems encountered in all stages of gelled fluid and slick water hydraulic fracturing applications. These formulations are based upon novel and innovative technologies that give enhanced biocidal efficacy and compatibility with friction reducers and biopolymers.

  • All formulations are compatibility enhanced to ensure optimum pumping performance of gel and slick water treatment programs 
  • Enhanced speed of kill and performance against all problematic bacteria, including acid producing bacteria, including acid producing bacteria 
  • Synergistiv control of FeS for superior control and mitigation blackwater 
  • Designed and supported by industry and application experts