What do transparent tape, fishing lures, surf boards, and antihistamines all have in common? They are just some of the 6,000 or more products made from oil and natural gas. When most people hear the words oil and natural gas, they think of the fuel that powers their car or keeps their home warm. That’s a correct if limited idea. Our modern life depends on oil and natural gas, and it is estimated that Americans consume petroleum products at a rate of 3.5 gallons of oil a day, and more than 250 cubic feet of natural gas per day per person. Even those intent on reducing their carbon foot print need electricity to power their electric cars, and it is estimated that more than 25 percent of the nation’s electric energy is generated from natural gas. Natural gas is now the number one source for electric generation, overtaking coal. The Energy Information Administration predicts that 46 percent of new generating capacity will come from natural gas by 2035.
Obtaining natural resources and turning them into a finished product is a long process. Workers and equipment are required at each step along the way, creating jobs and infusing the economy with dollars and government treasuries with tax dollars.
You’d have to be living under a rock to be unaware that the U.S. in general, and Pennsylvania in particular, is in the beginning stages of a shale gas boom. Western Pennsylvania sits atop the Marcellus Shale play, an enormous formation of sedimentary rock that spans the Appalachian Basin, running through limited areas in Virginia, Tennessee, Kentucky, and Maryland in the south, and with larger formations beneath much of Ohio, Pennsylvania, and New York in the north. Marcellus Shale can be found beneath about 60 percent of Pennsylvania.
Geologists have known for years that Marcellus Shale contained natural gas deposits, but it wasn’t until recently that technological advancements made Marcellus Shale the talk of the U.S. energy scene. In 2002, the U.S. Geological Survey estimated that Marcellus Shale contained about 1.9 trillion cubic feet of gas. That sounds like a lot of gas, but spread over hundreds of miles, it didn’t generate much interest for exploration. In the past, wells had been drilled, but they didn’t yield enough volume to warrant the capital investment needed to explore further development.
All that changed in 2003 when speculators drilled a well in Washington County which yielded a promising flow of gas, turning Marcellus Shale into a much sought-after gas “play,” the industry’s term for an area targeted for exploration.
In 2008, geoscience professor Dr. Terry Englander at Pennsylvania State University and geology professor Dr. Gary Lash at State University of New York at Fredonia shocked everyone when their estimates that the Marcellus Shale formation contained not 1.9 trillion cubic feet of gas, but an astounding figure of more than 500 trillion cubic feet of natural gas. It’s enough to supply the U.S. for a decade or more. These numbers continue to be revised upward.
So how do we get that gas out of the earth and make it into a usable energy source or product? The process is a long one. Here are some of the steps that occur before you are ever able to fill up your car’s tank or click up the thermostat to heat your home.
Since much of the gas lies under private property, land professionals research property records and meet with landowners to negotiate leasing agreements for the mineral rights to extract natural gas from beneath their land. The United States is one of the few countries in the world that allows for private mineral rights. In Canada and England, for example, all mineral rights belong to the government.
Geophysicists conduct seismic testing to explore the best sites for drilling wells. Using seismic trucks that send waves into the rock formations thousands of feet below ground, pockets of gas are located. Geophones, a type of microphone, interpret the vibrations from the waves, and this information is processed by computers to map the best places for wells. Another method is three-dimensional seismic testing, which places small charges into a series of holes 20 feet in depth. The charges are fired in sequence to generate data that is also picked up by geophones. That data is used to create an image of where it’s best to drill. Sometimes it is determined that an area is not suitable for drilling.
If a site is determined to be worthwhile for drilling, rigs are brought in. In our area, a process known as horizontal drilling has made previously unreachable pockets of gas available. The drill bores vertically and is cased and cemented from the surface to the strata of groundwater to protect the water. From there, it continues drilling and laying pipe until it comes just above the shale gas formation, then the drill bit turns horizontal boring into the shale formation.
The well casing keeps the well open, protects the earth and groundwater near the drilling site, and is installed along the length of the well.
Shale has naturally forming cracks, and it was discovered that if you applied pressure to those cracks, the rock would shatter and release the gas. It’s very similar to putting a piece of sand into a crack in a car’s windshield which allows more air to flow through the crack as you drive down the highway. In the horizontal portion of the well, the casing is perforated with a small charge, and then a fluid, composed of 99.5 percent water and sand, is injected under pressure into the well, which breaks open the shale, releasing the natural gas, and allowing it to flow to the well head.
To get the gas from the well, it travels by pipeline to compression stations. However, equipment, materials, and water must be transported.
Water Conservation & Restoration
Most water used in fracking is either transported by truck or by pipeline to a facility where the water is recycled. Each company has its own method of treating the water, but all of the water used in the process is monitored according to EPA guidelines.
Once the drilling is completed, the site is restored, and the well site left behind is usually a wellhead and two water tanks, monitoring equipment on a level concrete pad.
On average, it takes about 20 days for a well to be drilled, but it can yield natural gas for decades. There are multiple wells on each pad site.
A lot of natural gas is used for home energy: everything from heating your house, to the water in your hot water tank, to running your clothes dryer. Many more transportation vehicles are using natural gas too, and with the abundance of the gas in our area, many predict that number will only increase. In addition, natural gas is also used as a base ingredient for plastic, fertilizer, anti-freeze, and fabrics.
Like the little charges set up to explore the shale gas in our area, along each step of the process of bringing natural gas to market, the economy sees an explosion of jobs and opportunity.