Hydraulic fracturing

is fractures formation in gas-, oil-, water-saturated and other rocks under the pressure of the fed fluid. The operation is performed in a well in order to increase extraction rates by means of the multi-hole drainage system made as a result of extensive fracture network creation. The execution of formation hydraulic fracturing in gas wells became possible with the introduction of pump devices with the pumping rate of 3 to 4 cubic meters per minute and 100 MPa output pressure.
When the process fluid is being pumped into the well with a high flow rate, a high pressure is produced at the downhole. If it exceeds the horizontal constituent of the mine pressure, a vertical fracture is formed. In case it exceeds the mine pressure, a horizontal fracture is formed.
Gelled water and hydrocarbon based liquids (sometimes called slickwater) are widely used as fracturing fluids. Along with the process fluid a propping agent (sand or solid proppant with particles of 0.5 to 1.5 millimeters in diameter) is propped into the fracture to prevent it from healing. When gelled liquids with reduced leakage into formation and high sand-bearing capacity are used, downhole pressure can be increased with a rather low pumping rate while the proppant is transferred along the whole length of the fracture.