01-Biocide and Bactericide for Hydraulic Fracturing Stimulation Viscoelastic Surfactant (VES) Fracturing Fluid System

Introduction
The mixing water for the preparation of fracture fluid should be free of bacteria and enzymes. Either can cause degradation of the polymer and premature viscosity break. They can also prevent viscosity development. Bacteria produce enzymes to which most guar or guar derivative polymers are particularly sensitive.

Physical Properties and Hazards
Chemical Properties and Application
The biocide is added to the mix-water as early as possible before the bacterial problem develops. It can be continuously mixed during the treatment to prevent bacterial growth in the reservoir, but will be of little or no benefit to the stability of the fracturing fluid if added by continuous mix. This product will kill bacteria but cannot remove enzymes.
When using polymer-free systems (such as SurFrac), biocides or bactericides are NOT required because Biocide may interfere with rheological properties of SurFrac fluids.
Biocide is compatible with most additives used in crosslinked guar based fracturing fluids, but certain additives such as scale inhibitors, demulsifiers especially enzyme breakers might not be compatible with Biocide. Laboratory testing is required before using these additives together in fluid systems.