Hydraulic Fracture

Index

  1. What is Hydraulic Fracture?
    1. Aftermath of Hydraulic Fracturing
  2. Bibliography

What is Hydraulic Fracture?

Hydraulic Fracture is a fifty year old process employed by oil and gas companies to maintain nominal output pressure from reservoir rock, and thereby maximising their long term yield from the well. This process 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.

One ways to improve or maximise 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 fracture or hydraulic fracture is formed when a fluid is pumped down the well at high pressures for short periods of time (a matter of hours).

The high-pressure fluid (usually water with [WikiPedia]Benzene and other additives) exceeds the rock strength and opens a fracture in the rock. A propping agent, usually sand carried by high-pressure fluid cocktail, 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.

Aftermath of Hydraulic Fracturing

Apart from the over harvesting of wells and pressure damage to underlying rock, the main detremental effect of hydraulic fracturing is the polution of [WikiPedia]Groundwater that the benzene causes.

Bibliography

CategoryEnvironment

last edited 2005-03-31 14:08:31 by NathanReynolds