Marcellus Shale Maps and Guides
WHAT IS HYDRAULIC FRACTURING?
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The Marcellus Shale
A deep rock formation underlying much of Pennsylvania that is believed to hold trillions of cubic feet of natural gas. Recent advances in drilling technology have triggered an exploration boom that advocates say could transform Pennsylvania’s economy. But the drilling has raised concerns about potential environmental damage, including water contamination.
Popularly called “fracking,” the process uses a mixture of water, sand and chemicals to blast open the shale rock, freeing gas trapped in tight pockets to flow to the surface.
Traditionally, small-diameter, low-pressure lines that connect gas wellheads to processing stations or transmission lines. The Marcellus strike has changed the calculus – gathering lines from Marcellus wells may be the same diameter as interstate transmission lines and carry gas under the same high pressure. In Pennsylvania, new gathering-line pipes are produced from carbon steel like those in transmission lines.
Major lines that often carry gas across state borders, they generally range in diameter from 20 to 42 inches and are capable of transporting gas at pressures greater than 1,000 pounds per square inch. The pipe is produced from carbon steel.
These lines, which can be steel, cast-iron or plastic, deliver gas to homes and businesses that has been carried by transmission lines from producing regions.
These stations use a type of fan to reduce the volume of the gas, pressurizing it, and helping push it along the pipeline. The stations are typically placed at intervals of 40 to 100 miles along interstate transmission lines.
Pipeline companies use these stations to track the flow of gas through the pipeline system.