There are numerous overlapping technical terms that refer to the relatively innovative technological process used to drill for oil and gas — technology that yields many times, sometimes thousands of times more gas or oil than the conventional methodology,the vertical well. The terms overlap and interchange — hydrofracking; hydraulic fracturing; unconventional, high volume hydrofracturing; and the popular shorthand term, “fracking.”
All of them refer to the same process, which uses millions of gallons of fresh water treated with an enormously wide range of chemicals and sand forced under high pressure to shatter — that is, to fracture — rock formations thousands of feet underground.
This method was known as early as the late 1940s, but it was not until 2005 that the discovery of horizontal drilling suddenly liberated many times the amount of oil and gas locked into the deposits of shale. The innovation features an initial drilling with a rigid drill bit, as far as two miles down, with the drill bore protected by a cement casing. Then a second drill — flexible rather than rigid — bends and then drills horizontally as far as two miles. In 2009 a further technological advancement — “multi-stage fracking” — used plugs at various levels, pausing at each stage to frack and then descending further to repeat the process, consuming two or three million gallons of water.
Because this technique releases oil or gas in such exponentially greater quantities, it reverses the traditional concept of “striking oil” — or gas. It does not matter where the gas company sinks a well — the classic image of the “gusher” that explodes when the drill has reached the perfect place underground. What matters is the technique used to tap all of those valuable resources horizontally and systemically.
These two brief videos offer straighforward, objective explanations of the fracking process. in the Marcellus Shale.