Guar gum is needed for producing sufficient viscosity. Because less is required, costs are reduced. This would help explain its presence in so many things today. In addition to guar gum's effects on viscosity, its high ability to flow, or "deform", gives it very favorable rheological properties. It forms breakable gels when cross-linked with boron. It is used in various multi-phase formulations for hydraulic fracturing, in some as an emulsifier because it helps to prevent oil droplets from coalescing, and in others as a stabilizer to help prevent solid particles from settling and/or separating. Fracking entails the pumping of sand-laden fluids into
Hydraulic fracturing used to model information such as length, width and conductivity of a propped fracture. Injection of radioactive tracers along with the fracturing fluid is sometimes used to determine the injection profile and location of created fractures. Radiotracers are selected to have the readily detectable radiation, appropriate chemical properties, and a half life and toxicity level that will minimize initial and residual contamination. Radioactive isotopes chemically bonded to glass (sand) and/or resin beads may also be injected to track fractures. For example, plastic pellets coated with 10 GBq of Ag-110mm may be added to the proppant, or sand may be labelled