Hydro Fracturing of Water Wells
What is hydraulic fracturing?
This half century-old technology is used in oil and natural gas production. This technique allows oil or natural gas to move more freely from the rock pores where they are trapped to a producing well that can bring the oil or gas to the surface.
After a well is drilled into a reservoir rock that contains oil, natural gas, and water, every effort is made to maximize the production of oil and gas. One way to improve or maximize the flow of fluids to the well is to connect many pre-existing fractures and flow pathways in the reservoir rock with a larger fracture. This larger, man-made fracture starts at the well and extends out into the reservoir rock for as much as several hundred feet. The man-made or hydraulic fracture is formed when a fluid is pumped down the well at high pressures for short periods of time (hours). The high pressure fluid (usually water with some specialty high viscosity fluid additives) exceeds the rock strength and opens a fracture in the rock. A propping agent, usually sand carried by the high viscosity additives, is pumped into the fractures to keep them from closing when the pumping pressure is released. The high viscosity fluid becomes a lower viscosity fluid after a short period of time. Both the injected water and the now low viscosity fluids travel back through the man-made fracture to the well and up to the surface.