Hydraulic Fracturing

By: Rebecca Gelbutis

What Is Hydraulic Fracturing?

"Hydraulic fracturing, or “fracking”, is the process of drilling and injecting fluid into the ground at a high pressure in order to fracture shale rocks to release natural gas inside."

The Design

Steel surface casings are inserted into the well to depths of 1,000 to 4,000 feet to ensure that the fluid or oil or gas enter will enter the water supply. Casing is typically hollow steel pipe used to line the inside of the drilled hole (wellbore). The space between these casing “strings” and the drilled hole is filled with cement. Once the cement has set, then the drilling continues from the bottom of the surface cemented steel casing to the next depth. Until the oil and gas-bearing reservoir is reached (generally 6,000 to 10,000 ft), this process is repeated, using smaller steel casing each time. The "Kick Off Point" is where the vertical portion of the well begins its horizontal turn, and commences with the final portion of the well drilling process. This occurs roughly 500 feet above the shale formation.The distance of the horizontal section of the well may extend 1,000 to 10,000 feet. Production casing is lowered down-hole and cemented in place. The diagram shown below is a generalization of a Shale gas well in south central Texas.
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The Process

The fracking process occurs after a well has been drilled and steel pipe (casing) has been inserted in the well bore. The casing is pierced within the target zones that contain oil or gas. When the fracturing fluid is injected into the well, it flows through the holes into the target zones. Eventually, the target formation will not be able to absorb the fluid as quickly as it is being injected. At this point, the pressure created causes the formation to crack or fracture. Once the fractures have been created, injection stops and the fracturing fluids begin to flow back to the surface. Materials called proppants (usually sand or ceramic beads), remain in the target formation to hold open the fractures.

Usually, a mixture of water, proppants and chemicals is pumped into the rock or coal formation. Sometimes fractures are created by injecting gases such as propane or nitrogen, and acidizing occurs simultaneously with fracturing. Acidizing involves pumping acid (usually hydrochloric acid), into the formation to dissolve some of the rock material to clean out pores and enable gas and fluid to flows more readily into the well.

Marcellus Shale

"Marcellus Shale is a sedimentary rock buried thousands of feet beneath the earth’s surface."

Marchellus Shale has to do with natural gas production because of its large untapped reserve. The Marchellus Shale formation contains an estimate of more than 410 trillion cubic feet of natural gas. This could supply U.S. consumers' energy needs for hundreds of years.

Should We Rethink Fracking?

I personally feel that hydraulic fracking is dangerous and can cause more problems than help. Even though it does have some positive effects, there are many issues. The health of our planet needs to be considered.

Radiation Alarm

In South Huntingdon at a hazardous waste landfill, a radiation alarm was triggered by a truck loaded with Marcellus shale drill cuttings. The truck was ordered back to a Greene County drilling site. The drill cutting materials from Rice Energy's Thunder II pad in Greene County was confirmed to have a radiation level of 96 microrem. Any waste with a radiation level that reaches 10 microrem or higher must be rejected by the landfill. (A microrem is a unit used to measure the biological risk to human tissue from radiation. The average annual radiation exposure for a person in the United States is 620,000 microem, according to the Environmental Protection Agency. The average chest X-ray emits 4,000 microrem.)

Air Pollution

In Weld County, Colorado, it is estimated that 4 percent of the methane produced by these wells is escaping into the atmosphere.

A number of other air contaminants are released during construction and operation of the well site, transport of the materials and equipment, and disposal of the waste. Some of the pollutants released by drilling include: benzene, toluene, xylene and ethyl benzene (BTEX). These pollutants are known to cause short-term illness, cancer, organ damage, nervous system disorders and birth defects or even death. Fracking also contributes to triggering asthma and the formation of ozone “smog,” which reduces lung function. (This picture to the right shows normally invisible emissions of pollutants revealed by an infrared camera.)

It will release methane into the air which is 20 times as potent as CO2.

Water Consumption and Contamination

1-8 million gallons of water is used to complete each fracturing job. Most industrial uses of water are returned to the water cycle, but fracking converts clean water into toxic wastewater, which much of it has to be permanently disposed. This takes billions of gallons out of the water supply annually. (The table to the right shows the amount of water used for fracking since 2005.)

"In Pennsylvania, state regulators identified 161 instances in which drinking water wells were impacted by drilling operations between 2008 and the fall of 2012."

Leakage from liquid storage areas, leakage from injection wells, leakage during hydrofracking along faults or up abandoned wells, and seepage into the ground can contaminate groundwater.

Gas Well Drilling Affects Aquatic Life

In Washington County's Cross Creek Park, an unnamed tributary of Cross Creek Lake was polluted from a leaking waste water pipe from a Range Resources Marcellus shale gas well drilled. This waste killed fish, salamanders, crayfish and aquatic insect life in about three-quarters of a mile of the stream. The Range Resources drilled three Marcellus shale deep gas wells.

Road and Truck Traffic

The fracking process requires a lot of trucks. These 18 wheelers can weigh up to 80,000 pounds. They make thousands of trips to and from well. The Environmental Protection Agency (EPA) estimates between 300 to 1,300 truck trips for an individual well in the Marcellus Shale region. This amount of truck traffic may result in deteriorated road conditions, interference with traffic flow and annoyance to the community.

The contract truckers for the fracking work are paid by the load. This leads to the truckers driving fast which always them to do more loads and be paid more. The operations can be 24/7 non-stop. Many drive in truck convoys.