Hydraulic fracturing is a well stimulation technique

Hydraulic fracturing is a well stimulation technique designed to increase the productivity of a well by creating highly conductive fractures or channels in the producing formation surrounding the well. The process normally involves injecting a fracturing fluid at a sufficient rate and pressure to rupture the formation thereby creating a crack or fracture in the rock, and thereafter placing a particulate material or propping agent in the formation to maintain the fracture walls open by resisting forces tending to close the fracture. The propping agent or proppant must have sufficient mechanical strength to bear the closure stresses, provide relatively high permeability in the propped fracture, and resist chemical attack by liquids or gasses in the formation.