Hydraulic fracturing, or fracking as it’s more commonly referred to, is used to stimulate the production of oil and gas from unconventional oil and gas deposits – shales, coalbeds, and tight sands. These types of deposits need to be stimulated because they have a lower permeability than conventional reservoirs and require the additional stimulation for production.
Hydraulic fracturing involves drilling a well then injecting it with a slurry of water, chemical additives and proppants. Wells are drilled and lined with a steel pipe that’s cemented into place. A perforating gun is used to shoot small holes through the steel and cement into the shale. The highly pressurized fluid and proppant mixture injected into the well escapes and create cracks and fractures in the surrounding shale layers and that stimulates the flow of natural gas or oil. The proppants (grains of sand, ceramic beads, or sintered bauxite) prevent the fractures from closing when the injection is stopped and the pressure of the fluid is removed.