This is the process whereby the fissures and existing cracks within a geological formation are expanded and enlarged by the application of pressure. The process seeks to increase the permeability of fluid bearing rocks so as to increase the flow of the fluids through it.
The process is employed within the oil and gas sector to increase the permeability of the hydrocarbon bearing rocks. This promotes the flow of said hydrocarbons toward the well-bore. The increased permeability aids in increasing the productivity of the well-bore.
Typically it is employed in the extraction of what is know as “tight gas” and now it has found its place as the primary means of extracting and producing shale gas. Note that “tight gas” and shale gas are not the same, “tight gas” is gas that is produced from reservoirs of very low permeability, however shale gas is gas that is produced within shale formations that have the right amount of kerogenous material.
At its simplest the fracking process involves pumping fluid into the formation above the fracture pressure, this pressurized fluid helps to expand the naturally existing fissures this allowing for greater fluid flow. Now after the application of said fluid the fissures will shrink back to its original size. To combat this and preserve the gains of the expanded fissures proppant is pumped along with the fluid and this stays behind within the expanded fissures propping them open even after the pressure has ceased to be applied.
