U.S. President Barack Obama even endorsed the practice in his state of the union address last month. Extracting shale gas will “create jobs and power trucks and factories that are cleaner and cheaper, proving that we don’t have to choose between our environment and our economy,” he said.
But in recent years the process called hydraulic fracturing — “fracking” for short — has also become a flashpoint for environmental critics.
Why has a long-accepted practice now become such a hot button topic?
The Debate
Anthony Ingraffea, a professor of engineering at Cornell University, suggests there is confusion about fracking in conventional wells and fracking for natural gas in shale formations.
In fracking for natural gas in shale, a well is drilled both vertically and horizontally. Along that horizontal seam, which can extend for thousands of metres, hundreds of well pads are built to collect the gas. They intersect with thousands of pockets of gas which are distributed along the shale formation.
To fracture, or open up the shale’s pores, as much as 20 million gallons of highly pressurized fracking fluid — made of chemicals, water and sand — are pumped into the well. The shale then opens up and releases the gas, which flows back to the surface. It’s occurs on a much bigger scale than conventional fracking.
The Scope
Conservatively, there are close to 500 wells being hydraulically fractured in shale formations in the U.S. and Canada, said David Burnett, director of technology for the Global Petroleum Research Institute at Texas A&M University.
It’s “an oil and gas boom the likes of which we haven’t seen since the development of the rotary drilling rig in the 1800s,” Burnett said.
Some of the biggest shale gas formations in the U.S. are in Wyoming, Texas, New York (part of which extends into Ontario) and Pennsylvania.
Risks
With shale extraction comes what Burnett describes as a “tsunami of people and equipment,” which can lead to problems, particularly in a wilderness area.
The environmental risks are higher than in conventional drilling, said Cornell’s Ingraffea. Everything from groundwater contamination to a pipeline leak are possible, he said.
The equipment emits pollutants into the air. Fracking fluid, once it returns to the surface, contains chemicals and naturally occurring hazardous materials.
“The biggest controversy is clearly water,” said Robert Jackson, professor of environmental sciences at Duke University in North Carolina.
“Hydraulic fracturing takes millions of gallons of water to fracture a single well. Depending on where you are in the country, you may have to pump groundwater or take it from a stream.”
There often are no facilities for storing or disposing of the fracking fluid.
“People are worried about the chemicals from the fracturing fluid getting into their drinking water,” Jackson said.
A recent U.S. Environmental Protection Agency report found groundwater in an aquifer around Pavillion, Wyoming contained “compounds likely associated with gas production practices, including hydraulic fracturing.”
In addition, Ingraffea said, the infrastructure required to maintain these wells — processing equipment, compressor stations, trucks and highways — all bring potential risks. The wells and the pipeline could also fail. According to some studies seen by Ingraffea, at least 5 per cent of all new wells exhibit some kind of failure to contain hydrocarbons.
Climate change is another risk. Methane, a much stronger greenhouse gas than carbon dioxide, is emitted into the atmosphere during the extraction.
The disposal of fracking waste underground also causes earthquakes, Ingraffea said.
“The question is what frequency, what magnitude and what level is deemed acceptable,” he said.
Benefits
There are potentially huge profits for the oil and gas sector, with some of that flowing into government coffers. Towns and communities could also experience a boom in jobs.
The bigger dream? Reducing America’s dependence on oil.
“Without (fracking) you can’t get the gas out of the ground. There are huge amounts of gas locked up in shale and other formations. These technologies allow you to find and retrieve that gas,” said Jackson.
“Our conventional gas supplies are dwindling in North America. These unconventional sources are making up the difference.”
Original Article
Source: Star
Author: Debra Black
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