Although frac fluid is primarily composed of pure water and sand, additives are a vitally important part of the mix that must be added in the proper proportions for efficient fracking.
Some of the additives in frac fluid are temperature sensitive, making them more or less necessary depending on the temperature to which the fluid is risen during the hydraulic fracturing process. These include the following types of frac fluid additives:
One of the major reasons why additives are put in frac fluid is to prevent corrosion of equipment including the pipe through which the fluid is propelled. Common corrosion inhibitors that are frequently used in frac fluid include isopropanol, methanol, and formic acid.
Because metals typically corrode more easily at higher temperatures than they do at lower temperatures, corrosion inhibitors are particularly important in high temperature fracking operations.
Fluids tend to lose viscosity as their temperatures rise. Crosslinker additives are necessary in high temperature fracking to maintain the fluid's viscosity even at high temperatures. If frac fluid is not kept viscous as it is propelled into rock during fracking, it will be less effective at blasting through rock to gain access to shale gas reservoirs.
Common cross linker additives used in frac fluid include potassium metabolite, sodium tetra borate, and boric acid.
Another function of frac fluid additives is reducing friction between the fluid and the pipe through which the fluid is propelled during the hydraulic fracturing process. While maintaining viscosity is important, it's important to realize that viscosity is essentially liquid friction.
Because friction is increased with the increasing viscosity of the frac fluid, the proportion of friction reducers in the mix will be influenced by both the presence of crosslinkers and the temperature of the fluid during the hydraulic fracturing process. Chemicals that are typically added to frac fluid to reduce friction include ethylene glycol, methanol, and polyacrylamide.
Chemicals including glutaraldehyde and quaternary ammonium chloride are sometimes added to frac fluid to kill bacteria that are found in the water and in the the rock being drilled into.
These bacteria are killed because they are known to give off byproducts that are corrosive. Killing them therefore protects equipment from corrosion. These substances may be used in greater proportion when frac fluid is heated to high temperatures during fracking because corrosion occurs more easily when metal equipment components and water are kept at higher temperatures.
For more information, contact G-Force Industries or a similar company.