Skip to comments.Debunking fracking myths(hydraulic fracturing for oil & natural gas)
Posted on 04/28/2012 4:47:17 AM PDT by Las Vegas Dave
Fracking, a slang term for hydraulic fracturing, is a mining procedure that fractures rocks by injecting fluids and sand into cracks to force them apart, making it easier to extract oil and natural gas. Some say it can pollute drinking water and farm lands and even lead to earthquakes. But Robert W. Chase, professor and chairman of the Dept. of Petroleum Engineering and Geology at Marietta College (Ohio), believes otherwise. In fact, he took the time to shed some light on recent myths about fracking that have sprung up.
Myth No. 1: Fracking could contaminate aquifers that supply drinking water. Hydraulic fracturing has been done for decades and on more than 1 million wells in the U.S. since the late 1940s. Combining fracking with horizontal drilling lets drillers extract oil and gas from geologic areas that were practically inaccessible in the past.
Some mistakenly say the practice can pollute water tables which lie just a few hundred feet or less below the surface. Fracking is done well below 7,000 feet, and solid rock separates the oil and gas deposits from shallow groundwater aquifers. This rock buffer makes contamination from fracking virtually impossible.
In addition, wells are built with at least four layers of steel casing and concrete and are cemented in place, creating a solid divider between gas production and any fresh-water aquifers. Energy Secretary Steven Chu recently asserted: We believe its possible to extract shale gas in a way that protects the water, that protects peoples health. We can do this safely.
Myth No. 2: A huge amount of water is used in fracking. Extracting natural gas from shale formations with fracking uses less water than that needed to produce other sources of energy such as coal and nuclear. In 2010, the 3,500 shale-gas wells drilled in the U.S. accounted for about 0.02% of the countrys total water usage. Companies drilling in major shale formations are quickly adopting recycling methods that treat 70 to 100% of the returned fracking fluids for reuse in another well.
Myth No. 3: Fracking can make tap water flammable. There are places where methane appears to have leaked into the water supply making it flammable. But the consensus among state environmental officials is that this problem was not caused by fracking. Instead, these officials blame water wells drilled in areas with high natural levels of methane. Also, some small oil and gas companies over the years didnt take proper care in cementing their wells or in plugging old wells.
Today companies use better well casings and improved cementing to ensure no shallow formations (aquifers) are contaminated. Concurrently, state agencies have established regulations regarding well construction and water management designed to prevent methane migration and protect water supplies.
Myth No. 4: Fracking can cause earthquakes. Federal officials and geologists have confirmed that fracking itself as distinct from wastewater disposal is not responsible for recent tremors felt in Ohio and several other states where fracking takes place. William Leith, senior science adviser for earthquake and geologic hazards at the U.S. Geological Survey, told National Public Radio recently: Fracking itself probably does not put enough energy into the ground to trigger an earthquake. Thats really not something that we should be concerned about.
Oil and gas waste water disposal wells, on the other hand, do have a history of causing tremors, most recently in Youngstown, Ohio. However, by reducing the volume of water injected, the depth of wastewater injection wells, and avoiding earthquake-prone areas, the risk of inducing tremors, however small, can be reduced.
Myth No. 5: The public cannot afford to rely on state regulation of fracking. Just about all of the states, including Ohio, insist that fracking and getting rid of wastewater be done properly. In the decades since fracking was first used in Oklahoma in the 1940s, there have been more than a million oil and gas wells drilled across the country. The instances of water contamination have been miniscule compared to the number of wells drilled. And not one of those contaminated wells was caused by fracking. Much of the credit for this safety record goes to rigorous state regulation.
States are stepping up and doing a good job, says federal EPA Administrator Lisa Jackson.
On the positive side: According to a study by IHS Global Insight, in 2010, U.S. shale gas production due to fracking generated $76 billion toward GDP, accounted for $33 billion in capital investments, was responsible for $18 billion in tax and federal royalty revenues, and supported 600,000 jobs. Experts estimate that nearly $2 trillion in capital investments will be created into the U.S. shale-gas industry through 2035. The benefits of such large investments will spread through communities, businesses, and governments.
Good article. Thanks.
I used to work in the water table cleanup business. Mainly we cleaned up DNAPLS - basically heavy petrosludge that seeped out of a leaky oil tank. The D in DNAPL meant the sludge hit the water table (below ground) until it found a ledge or cubby hole to sit on. So that might answer part of your question - with fracking at 7000 feet, the DNAPLS will go down not up.
There are LNAPLs - L is for light - those could be problematic because they rise up until they float across the top of the water table. Most companies are pretty cautious but there are a handful of rogue firms out there basically blowing up rocks at depth to see what happens. It’s a bonanza akin to the gold rush. At a GREAT time for the US too, with China and India adding expotentially to the world energy demand.
Personally I think it would be a good idea for the industry itself to come up with a way to reign in the wildcats most likely to cause headaches for everyone. That would be better than a few bad apples closing off this great opportunity (ala coastal oil drilling or building nuclear power plants).
I like your comments.
Differently put: The same sealing layers which permitted the oil to accumulate and prevented it from migrating to the surface prevent the frac from contaminating the layers above it. The idea is to break the rock with the oil or gas in it to produce the oil and/or gas, not allow it to escape the natural trap from which it will be recovered.
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