The state of Alaska experiences an estimated 2,400 earthquakes every year. Many Alaskans take them as just another part of life in Alaska and, as a natural phenomenon, they are, but what if there was a human cause for earthquakes? While it might seem like something out of a low budget spy movie, it is possible to drill down into the earth and create fractures in the rock. Fractures that can and do produce earthquakes.
Fracking
Fracking is the process of injecting highly pressurized fluids into a wellbore to fracture deep shale and release natural gas. In this process a wellbore is drilled into reservoir rock formations and highly pressurized fluids are injected into the reservoir, this creates new channels in the rock which increases the extraction rate of fossil fuels.
Widespread in the United States, there is some controversy about the process of hydraulic fracking. Questions about potential harmful side effects to the environment have raised concerns about the process and the possibility that fracking may cause contamination of waterways and groundwater tables.
The process begins with well construction. A well is drilled down vertically to the shale reservoir, then horizontally across the layer. Water, sand and chemicals are then pumped into the well to fracture the shale and release the fossil fuels. The well is constructed using a concrete casing to help contain both the fluids used in fracturing and the oil or gas from entering fresh water aquifer layers.
A “perforating gun” is used to inject the fracking fluids into the rock layer, the high pressures can cause fractures that can extend for up to several hundred feet through the shale. Between 15 and 80 percent of the fluids are extracted back out of the well and, in some cases, may be used on additional wells in the area.
Ban on Fracking
There is concern about the environmental impact of fracking, and these concerns have lead to a ban on the process in France until proof has been provided that the process will not damage the environment.
An article on Bloomberg early last month about the French ban on fracking quoted French President Nicolas Sarkozy as having stated, “This won’t be done until it has been shown that technologies used for development respect the environment, the complex nature of soil and water networks.”
Is fracking coming to Alaska?
While fracking is viewed with concern by places such as France, it is widespread in the United States. It may even be used on the North Slope in Alaska soon. In March of this year an article in the Alaska Dispatch revealed that a small Texas oil company might bring fracking to Alaska.
Great Bear Petroleum LLC, based out of Austin, Texas, seeks to use fracking on the North Slope to help boost the oil flow in Alaska. The company speculated that if Alaskan investors were to assist in financing more wells than the company could afford on their own, that there could be an estimate of up to 1 million barrels a day of oil flowing through the Alaska Pipeline.
A tempting prospect for the Alaskan economy, but would fracking be a good idea in Alaska when the latest concern about the process centers around the theory that fracking might be connected to earthquake activity?
Does fracking cause earthquakes?
Based on 2006 data from the Alaska Earthquake Information Center, Alaska has between 50 and 100 earthquakes every day. In an average year there are roughly 2,400 earthquakes in Alaska that range in magnitude from 2 to 8. Recent activity can be seen on the AEIC website for recent earthquakes in Alaska.
With so many naturally occurring earthquakes, should Alaska be quick to introduce processes that might trigger man-made earthquakes, even small ones?
It must be noted that fracking is not currently known to cause large scale earthquakes. In a Department of the Interior live chat about the East Coast earthquakes, Dr. Michael Blanpied, Associate Coordinator for the USGS Earthquake Hazards Program, explained that while fracking can cause very small earthquakes, it is not believed to cause larger earthquakes.
“The thing that can induce large earthquakes is the high pressure fluid injection, waste fluid injection, that’s done in some places,” said Blanpied. He went on to say, “And just to be clear, the connection between fracking and fluid injection and earthquakes is an area of active research and really we’re only starting to learn about how those things are connected.”
In a recent article in the New York Times on the earthquakes in England, Stephen Horton, a seismologist at the University of Memphis, said, “Generally speaking, fracking doesn’t create earthquakes that are large enough to be felt.” An article at Technorati about the earthquakes in Oklahoma quotes the Oklahoma Geological Survey’s statement on the possibility of recent earthquakes in the area of Garvin County, OK being connected to a nearby deep hydro-fracturing project: “…The strong correlation in time and space as well as a reasonable fit to a physical model suggest that there is a possibility these earthquakes were induced by hydraulic-fracturing.”
How strong are fracking induced earthquakes?
Connections between earthquakes and hydraulic fracking are still a new area of research, however, there is some evidence that the earthquakes produced by fracking are quite small. In the The SEAB Shale Gas Production Subcommittee Ninety-Day Report of August 11, 2011 the subcommittee made note of several areas that could contribute to understanding the safety and risk of shale gas operations to the environment. Included in those projects was a need to understand the induced seismic activity that could be triggered by hydraulic fracturing and injection well disposal. A note connected to this point states:
“Extremely small microearthquakes are triggered as an integral part of shale gas development.
While essentially all of these earthquakes are so small as to pose no hazard to the public or
facilities (they release energy roughly equivalent to a gallon of milk falling of a kitchen counter),
earthquakes of larger (but still small) magnitude have been triggered during hydraulic fracturing
operations and by the injection of flow-back water after hydraulic fracturing. It is important to
develop a hazard assessment and remediation protocol for triggered earthquakes to allow
operators and regulators to know what steps need to be taken to assess risk and modify, as
required, planned field operations.”
What might the side effects of fracking be in Alaska?
Questions should be asked about the possible environmental impact of hydraulic fracking in the North Slope and the possible risks weighed against the potential benefits.
Earthjustice has a map of what it refers to as “Fraccidents” that have occurred in the United States. Their map lists incidents reported near an area where fracking is being used.
Earth Times brings up a subject that is of concern to all Alaskans, the possible impact of hydraulic fracturing on fish.
For those wanting to know more about risks of volatile organic compound (VOC) emission and hydraulic fracking, the EPA addresses the use of fracking, or hydraulic fracturing, and VOC emissions in their 207 page technical support document on limiting VOC emissions in the Oil and Natural Gas Sector.
The SEAB Shale Gas Production Subcommittee Ninety-Day Report of August 11, 2011 lists the four major areas of concern for the subcommittee as being:
- Possible pollution of drinking water from methane and chemicals used in fracturing fluids
- Air pollution
- Community disruption during shale gas production
- Cumulative adverse impacts that intensive shale production can have on communities and ecosystems
The SEAB report also notes: “Many in the concerned public use the word “fracking” to describe all activities associated with shale gas development, rather than just the hydraulic fracturing process itself. Public concerns extend to accidents and failures associated with poor well construction and operation, surface spills, leaks at pits and impoundments, truck traffic, and the cumulative impacts of air pollution, land disturbance and community disruption.”
Is fracking on the North Slope right for Alaska?
There is a balance that needs to be considered carefully in the introduction of hydraulic fracturing on the North Slope. Potential gains that will need to be measured against possible impacts to the environment. Is a good idea for Alaska, or is fracturing something that Alaska should avoid until we have more information on the side effects to the environment in areas where fracturing is used?
Share your thoughts and opinions in the comments.
Few things bring back the feel of an old fashioned family Thanksgiving like a cardstock turkey with a crepe paper fan-tail. I used to adore the delicate look of the paper tails on the turkeys.
