Hydraulic Fracturing; an environmental topic

Second in a series

Hydraulic Fracturing or “fracking” has been used for over 60 years, and is the process of mining for natural gas and oil.

This has been a topic of debate among many groups within the United States for the past several years.

“It is used to produce oil and gas,” said deputy director of the Oil and Gas Commission Sidney office Stan Belieu.

The hotly debated aspect of “fracking” has been safety issues and if this old form of mining – with its new twist of horizontal mining – is environmentally safe.

The answer for this area is, yes, it is safe, according to Belieu.

However, there are many reasons behind this answer and why Nebraska’s panhandle is a great area for hydraulic fracturing.

One reason besides the reservoirs being in a vacuum Belieu said is “Geologically we have more things that protect us. Right around here, we have about 3,000 feet of shale that separates the zone where the oil and gas is produced and the drinking water we have, so we have this massive layer of shale that is impermeable, so you couldn’t fracture through that.”

There are several rock formations where a company has to drill through in this area before tapping into a well, which is one reason horizontal fracturing in this area is safer.

“When you go up the under pass,” looking towards the bluff where 13th turns into Cedar Str., “you can see a good example of the (rock) formations in the area.”

Belieu said within Cheyenne County the most common formations are the Ogallala formation, Brule formation a real tight sooty limestone formation, which for the most part has no water in it because it is so hard and tight, once through there maybe the Chadron formation, and then shale.

When describing the shale Belieu said, “That is just a black marine shale that is just mud, hardened mud. You will have about 3,500 pure shale,” before getting to where oil and gas may be found.

Within the United States safety issues for fracturing are still, “regulated by the states and the state oil and gas agencies. So additional regulations are coming from each state,” Belieu said.

Within area safety measures all drilling companies are required to follow are always found within the permits filled at the court house, Belieu said, and are made available for viewing in the local newspapers.

Such is the case for the big operation on Road 83 east of Potter.

Within these permits some of the information the company must provide, according to Belieu are, “how much surface casing which is a steel casing size they are going to set on a well.

“We require that to set on through drinking water, it has to be submitted. Then we require production casing that is to be run inside that surface casing, and that has to be submitted up through the formation,” Belieu explained.

Also according to Belieu, there newer regulations that are supposed to pass through the last steps in the Nebraska Legislature, the hold up is the Governor and Attorney General’s office still need to sign off on them, but has passed through the Oil and Gas Commission.

These new regulations are, “requiring fracking through a separate work string and requires the chemicals used as part of that hydraulic fracturing operation be disclosed using a website called ‘Fracfocus.’”

In other words, everything the drilling companies used within their operations during fracturing would have to be disclosed and available for the public to access without problem online.

“In addition to those casings, strings and cement,” when horizontally fracturing, as was done during the drilling of the two wells newly formed in Cheyenne County, Belieu said there are also requirements. “These must have additional strings and cement, and they are deeper so they are going to formations that are very deep.

“So if you think about it you have these massive over burdened of rock that separates where the formation (reservoir of oil\gas) is to where the drinking water is above it, there are around 7,000 feet from where the oil and gas are, from where the drinking water is,” said Belieu.

When asked about the likelihood of the drilling causing perforations in the rock that would allow for the oil and gas to leak into the drinking water Belieu said, “It is very, very, very unlikely. It’s 10 to the minus eight or something like that, so it’s virtually impossible.”

Much of this impossibility is because of the regulations company drilling the vertical and horizontal wells must follow. Regulations Belieu said are looked at in “a national and international sense to ensure Nebraska’s water is protected. Not just the water but everything else too, environmentally, against not just hydraulic fracturing but all hole and cast type operations.”

Other hole and cast type operations include drilling for drinking water.

Once the well is closed or tapped out the requirements for safety then focuses towards, “they are cemented.

“The surface casing stays there, you can’t take that out, it always stays there, but what we require is down hole, at the producing formations you set cement plugs, so approximately 100 ft. of cement across the producing formation. Then you come up the hole and the base of surface casing so right before you get to the drinking water you set approximately another 80 to 100 ft. of cement, and then at the top you set more cement. So we require cement plugs.”

Belieu said the amount of shale we have is also beneficial in sealing off the tapped well by sealing back together.

Due to the fact sink holes and the way they are geologically formed, through running water, Belieu said the risk of sink holes is insignificant if at all.