"Don't Frack Me Up"
To many walking the planet, fracking has a seriously bad reputation. Thanks to hyperbole and misinformation, fracking opponents have convinced a lot of people that the operators who drill and then hydraulically fracture underground rock layers thumb their noses at and even hate the environment.
Anti-fracking claims may be twists on reality – for example, that a legislative loophole makes fracking exempt from the America's Safe Drinking Water Act, when really this federal legislation never regulated fracking because it is a state concern. Then there's the completely absurd, such as the idea that frac operators are allowed to and regularly do inject frac fluids directly into underground water supplies.
We decided to set the record straight by using facts, not playing on emotion like many of the frac-tivists do. It's important because unconventional oil and gas constitute an increasingly pivotal part of the world's energy scene. In the United States, where shale gas abounds but imported energy rules the day, this is especially true.
America's shale deposits hold a heck of a lot of gas. According to the United States Geological Survey, the Marcellus Shale alone is home to 84 trillion cubic feet (TCF) of technically recoverable natural gas. Estimates of the amount of recoverable gas contained in all of America's shale basins range as high as 3,000 TCF.
To access this gas, fluids made of water, sand, and chemicals to increase lubrication, inhibit corrosion of equipment, and possessing other qualities are pumped into the shale formation. When the pressure from the fluids exceeds the strength of the rocks, the rock fractures, and in a demonstration of might by the mighty small, the granules of sand prop the fractures open. Once the fracturing is completed, the internal pressure from the formation pushes the injected fluids to the surface again.
Frac wells are only open to the surrounding rock at the depth of the target formation. Starting at 250 feet (76 meters) or thereabouts above the producing interval – it varies a bit from state to state – the production casing must be cemented. This graphic, borrowed from the Texas Oil and Gas Association, shows what the procedure entails. Source/full story