Guar gum an oil or natural gas reservoir at a high pressure and flow rate. This cracks the reservoir rock and then props the cracks open. Water alone is too thin to be effective at carrying proppant sand, so guar gum is one of the ingredients added to thicken the slurry mixture and improve its ability to carry proppant. There are several properties which are important 1. Thixotropic: the fluid should be thixotropic, meaning it should gel within few hours. 2. Gelling and degelling: The desired viscosity changes over the course of a few hours. When the fracking slurry is mixed, it
Guar gum mannose. The backbone is a linear chain of β 1,4-linked mannose residues to which galactose residues are 1,6-linked at every second mannose, forming short side-branches. Guar gum has the ability to withstand temperatures of 80 °C (176 °F) for five minutes. Guar gum is more soluble than locust bean gum due to its extra galactose branch points. Unlike locust bean gum, it is not self-gelling. However, either borax or calcium can cross-link guar gum, causing it to gel. In water, it is nonionic and hydrocolloidal. It is not affected by ionic strength or pH, but will degrade at extreme pH