During fracturing operation
During fracturing operation there is no chemical reaction. Any chemicals added to the frac water is to reduce friction and carry the propping agent such as sand, glass beads or in some cases ground walnut hulls into the formation. These propping agent are deposited in the shale formations and alow the gas to move and flow toward the production well. The water and chemicals are then allowed to flow back out of the formation and back into the well bore and then into the frac tank containers the water was in before the frac operation started. The propping agents are left in the formation to allow the free flow of natural gas to the well bore. Many of the fracking fluids have been improved to prevent contamination even if spilled at the frac site and are totally biodegradable.