Gas Drilling Rig In Texas – Thanks to Wikipedia
In my last blog post I took the position that natural gas hydraulic fracturing (fracing) is a good thing. This is an assertion that is born out by the history of natural gas drilling around the world over the last twenty to thirty years. Indeed, hydraulic fracturing has been used in one form or another for the last seventy plus years!
The technology has enough history, and the practitioners enough expertise that hydraulic fracturing should not be a problem, anywhere. It is physically impossible for seepage from a fractured shale formation over a mile deep to get to the surface. There are just too many layers of other, different types of rock prohibiting that seepage. The greatest risks for environmental problems lie elsewhere, not with the actual fracturing of a shale structure.
The environmental risks of any drilling technology can be expressed in three categories:
Water – This is perhaps the most common pollution problem found at a drilling site. The hydraulic fracturing itself does not cause a problem. Most environmental problems linked to fracing are caused by the mishandling of drilling muds, fracing water, waste water, transportation spills of toxic chemicals, and improperly constructed wells. The literature is very clear on this account. If the well is properly constructed, and if the fluids are handled properly, there is no problem. Please read this article from the Shale Gas Wiki.
Much of the so-called evidence against natural gas hydraulic fracturing is anecdotal. It is just one uninformed, emotional story after another. The people in New York State are rightfully concerned about the natural gas drilling into the Marcellus Formation. The same shale formation underlies portions of Pennsylvania, West Virginia, and Ohio.There have been reports in these states of methane pollution of the drinking water. This is not unusual.
Extent of Marcellus Shale Formation
In one study it was found that out of 60 water wells tested in Pennsylvania and New York, eighty-five percent showed thermogenic methane content. This means that the gas was caused by natural seeps from deep in the earth. Thermogenic methane comes from deep underground, and biogenic methane is the stuff produced by biomass (garbage, etc.) near the surface. There had been no natural gas or oil drilling in that area.
The Marcellus shale structure shows up at different depths across Appalachia. In some places it is barely 1,000 feet under the surface, and in others it is over 8,000 feet beneath the surface.
Water drawn from wells that receive water from a coal seam has methane and other toxic chemicals with it. Water wells are a large source of the methane problem, but the consumer doesn’t know this because methane is colorless, odorless, and tasteless. There are about 20,000 unregulated water wells drilled in Pennsylvania and New York, every year. The probability of getting methane in the well water from natural sources is high.
Also, in about a thirty year stretch lots of gas wells were drilled in the Marcellus shale. Mistakes were made as the technology was developed. Many of the negative attitudes and stories originate in that development period.
Fracing is blamed for a lot of things. Just because there are natural gas wells in the area does not automatically mean that hydraulic fracturing is at fault.
Air Pollution – Natural gas is mostly made up of methane. In the natural gas extraction process, there are natural gas liquids produced, also. These are ethane, butane, and propane. There are some nasty gaseous compounds removed, also, and this is where air pollution can occur. If the removal processes are faulty, there will be escaping gas into the atmosphere.
Because there are over 860,000 oil and gas wells in the USA, it is safe to say that the oil company people have figured out how to keep the air unpolluted at drilling and processing sites.
Environmental activists go overboard on the danger of methane, and the risk it may pose to the environment. Remember, the natural gas drillers cannot make money from gas that is escaping to the atmosphere. They have a huge incentive to be safe and responsible with their operations.
It comes down to the fact that air polluting wells are not a technology problem.
Land Use – Here come the earthquakes. One of the most misunderstood risks about hydraulic fracturing is that they can produce earthquakes, usually micro-seismic events. We are not talking about the New Madrid quakes of 1811 and 1812 (the largest in the nation’s history). The seismic events caused by hydraulic fracturing, for the most part, cannot be felt on the surface. So, when someone says that they felt an earthquake and it was caused by fracing, season the information with a little salt.
Drilling wells is an ugly business. Ugly is pollution, too. The drilling structure is from fifty to one hundred feet tall. There is cleared land to accommodate the drilling equipment, fluid storage, and transportation equipment. Plus, roads have to be built to access the sites. With all those roads and tanker trucks come chemical and toxic water spills. This is the most common and greatest environmental risk in the whole process. This is also the most manageable portion. There are state and federal regulations about drilling, transporting, and cleaning up spills. Spills are avoidable.
So, there are real risks linked to natural gas shale hydraulic fracturing. All these risks can be properly mitigated. The technology is basically not a problem. The problems are management problems. With proper well construction, liquid transport and handling, and attention to details, environmental risks are relatively small.