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The techniques of hydraulic fracturing, or fracking, and horizontal drilling have come together over the past decade to change the American energy landscape. Now more and more researchers are looking into the potential risks hydraulic fracturing, or fracking, and horizontal drilling could pose to the environment and human health.| Long Read
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It's a remarkable feat of engineering when you think about it.Johannes Schwank, U-M chemical engineering professor

A drill bit tunnels down a mile into the Earth, curves sideways, then burrows across for thousands more feet. A pump shoots high-tech fluid through the channel with the force equivalent of two pick-up trucks squeezed onto one square inch. The fluid’s sheer water pressure splinters rock that’s 400 million years old, freeing trapped natural gas and sending it back through the well to be captured at the surface.

Stripped of any controversy, that – in a nutshell – is how the shale gas revolution is happening one well at a time. So much gas has been coming up from ancient, deep rock formations known as shale that the United States has become the world’s top gas producer and could be a net exporter by 2035.


The combination and advancement of two relatively old techniques – horizontal drilling and hydraulic fracturing, or fracking – have made this possible. They’re enabling industry to tap trillions of cubic feet of gas from places previously deemed too expensive or difficult to get to. Now they’re being used to go after oil as well.

“There’s a lot that has to come together to make something like this happen,” said Johannes Schwank, a chemical engineering professor at the University of Michigan who is researching fracking technology as part of a university-wide study on the practice.

“It’s a remarkable feat of engineering when you think about it.”

Shale is the source rock where the natural gas was made. These formations – known to exist in 32 countries – trace their roots to the days before the dinosaurs, when sand and silt settled with dead animals and plants on the bottoms of shallow seas.

Before horizontal drilling and fracking, you couldn’t efficiently tap source rock. You had to find a reservoir of gas – a holding tank, of sorts – sealed with cap rock that was keeping the fuel in place. What makes shale special, and also tough to drain, is that it serves as the source, the reservoir and the cap all in one. To learn more about how hydraulic fracturing and horizontal drilling work to pry the gas from its grasp, Michigan Engineering visited a well in the early stages of drilling in Pennsylvania.

1. Drill down more than a mile

In late January, snow dusted the Endless Mountains of Susquehanna County, one of the earliest hubs of gas drilling on this side of the Mississippi. In this county, Cabot Oil & Gas alone has 200 wells that reach down to the Marcellus shale, now believed to hold one of the world’s largest reserves of gas. On a farm off a dirt road, a drilling rig stood 10 stories high on a 10-acre well pad.

Halfway up, in a control room known as the dog house, the driller sat in a captain’s chair flanked with computer monitors. He faced a window to the rig floor. Outside, a 17.5-inch mud-coated drill bit spiraled down.

“How deep are we?” asked Bill desRosiers, Cabot’s external affairs coordinator.

“About 302 feet,” the driller replied. “We’re in surface sandstone.”

“By my calculations, we haven’t drilled down to the aquifer yet,” desRosiers said.

2. Protect the Goundwater

In this region, the groundwater aquifer starts about 500 feet below the surface. The water wells of rural residents reach to this sandy layer that’s saturated like a wet sponge. The drill goes right through it, down to the hard rock at its bottom. At that point, burrowing stops so the company can reinforce the well.

“When everything is said and done,” desRosiers said, “the well through the aquifer will have four to five different layers of casing and cement to protect it from whatever we’re doing inside in the Marcellus and whatever’s already in the aquifer from entering our operations.”

This might not always be foolproof, though. While most people with gas wells on their land haven’t complained of adverse effects, some say their water has changed. One immediate concern is methane – the main component of natural gas. It’s not considered toxic, but it is explosive. The state of Pennsylvania has halted Cabot’s operations in a nine-square-mile section of the county because of a correlation between gas drilling and higher methane levels in the aquifer. This is a complicated issue. Methane in water isn’t a new problem in the area and Cabot maintains its operations haven’t exacerbated it. Studies from Duke University and the EPA due out in the next few years could give telling insights.

3. Curve the Well Sideways

We use hydraulic fracturing to go in and open up all the little nooks and crannies and crevices.Bill desRosiers, external affairs coordinator for Cabot Oil & Gas

Below the water table, the team keeps drilling 6,200 feet to its destination: the Marcellus. Geologists on site verify when they get there. Then they’re ready to make the turn.

The curve happens little by little over a quarter of a mile and 40 pieces of steel pipe. Each section is flexible enough to bend two or three degrees. Beyond it, the length of the horizontal leg can be up to a mile long in Cabot’s case. Other companies go out further. Cabot pours cement outside the length of the well. Not all companies do.

DesRosiers points out that a horizontal well means a smaller footprint on the surface. One of these unconventional shale wells can empty an area that would take 10 to 20 traditional vertical wells to drain.

4. Make Holes in the Horizontal Leg

Next up is perforation. Companies have to make holes in the steel well pipe and the cement around it so their fracking fluid can reach the formation. To do this, they lower a special gun loaded with bits of explosives, Jim Peters, operations manager for Northstar Energy, explained in a phone interview. A finished well will have a couple hundred holes, each about the size of a dime. The explosions bore several feet into the shale.

5. Pump in the Fracking Fuel

You could think of shale as structured like baby Swiss cheese, with the gas stuck in microscopic pores.

“So we use hydraulic fracturing to go in and open up all the little nooks and crannies and crevices,” desRosiers said.

The fracking fluid used in deep gas wells today is made of five to seven million gallons of water, sand or ceramic beads to prop open the fractures, and a half of one percent total of about a dozen different chemicals, desRosiers said. The chemicals kill bacteria, reduce friction and scaling, and evenly distribute the sand grains, among other purposes. Some are safe to eat. Guar gum, which thickens the fluid, is common in processed baked goods, for example. But others are regulated hazardous substances, and the EPA is focusing on them in its study into whether fracking affects drinking water, due out in 2014.

Because today’s wells are so deep and long, it takes a lot of pressure to frack them – between 8,500 and 9,000 pounds per square inch. That’s like squeezing the weight of two pick-up trucks onto the space of one square inch, Peters said.

6. Capture the Gas


While the well is being installed, companies are also putting in the storage tanks and pipelines that will carry the gas through a separation plant to be cleaned, and eventually to cooking stoves, home-heating furnaces and manufacturing plants. Once it’s all in place, the surface footprint shrinks to one acre – just smaller than a football field. DesRosiers expects most of his company’s wells to produce gas for 50 years. So for half a century, landowners will receive royalty payments.

The environmental concern during this phase is air pollution. Natural gas is often considered a cleaner fuel because when it’s burned, it releases fewer pollutants than other fossil fuels. That’s true, but a Cornell University study asserts that shale wells could leak significantly more methane than conventional gas wells – enough to make their gas aggravate climate change more than burning coal would over the next 20 years. Raw methane is a potent greenhouse gas with perhaps twice the short-range warming potential as carbon dioxide.

7. Improve the Practice

IMAGE:  Kenneth Malialek holds up a jar of water that he claims came from his water well and includes heavy metals.

In 2011, an MIT study counted 43 incidents related to shale gas drilling over the previous few years. The list includes two blowouts, 14 on-site surface spills and 20 reports of methane contaminating drinking water, likely due to inadequate cementing of the well casings. While the study says its tally is not exhaustive, it also urges readers to put the numbers in the context of the thousands of fracked shale gas wells in the U.S. today.

“Let us be honest,” said Schwank, who is the James and Judith Street Professor of Chemical Engineering. “Things can happen. We have seen the nuclear reactor in Fukushima fail. A meteorite can strike. There’s always the unforeseen.

“This technology has a track record of comparatively low failures compared to other industries,” he continued. “Coal mining, for example, has a much higher accident rate. So does the construction industry.”

Engineering researchers around the country and the world are working to make fracking a cleaner and safer process. In Pittsburgh, they’re examining how the cement in gas wells cures in the presence of dust, mud and water. In Minnesota, they’re using bacteria to clean fracking wastewater. In Japan, they’re testing fracking fluids made of carbon dioxide that save water and make more fractures. Those are just a few examples.

The feats of engineering will continue. But not everyone will be satisfied.

“People think technology is going to save the day. In a perfect world, it would. But humans make errors, and there’s too much we don’t know about deep underground,” said Rita Chapman, coordinator of the Michigan Sierra Club’s Beyond Natural Gas program. She’s been advocating for stricter fracking laws in her state for the past few years.

“It comes down to what’s the level of perfection that we want. Our precious Great Lakes deserve nothing less than perfect. I want perfect.”



The professor picked up a brown envelope and emptied the contents into his hands: two black rocks.

“What I have in front of me,” said Brian Ellis, assistant professor of civil and environmental engineering at the University of Michigan, “are two samples of the Marcellus shale.”

He pointed to the tell-tale “poker chip” layering in one.

“This is the type of shale you’re likely to produce natural gas from.”

I think the question still remains whether or not hydrofracking is a big deal. That's the reason we as a society need to focus on this issue.Brian Ellis, U-M assistant professor of civil and environmental engineering

They had come in the mail a few weeks earlier – his lab’s first specimens of the source rock that’s changing the global energy landscape, dotting the American countryside with drill rigs and wells and turning the term “fracking” into a household name you can use in polite company.

The use of horizontal drilling and hydraulic fracturing techniques to recover gas has jumped 12-fold over the past decade in shale formations like the Marcellus under Pennsylvania, West Virginia and Ohio, and the Barnett under Texas, according to the Energy Information Administration. The U.S. now produces more natural gas than any other nation. Most recently, companies are turning to these techniques to bring up shale oil in North Dakota.

As the scale of the industry has grown, so have concerns about its effects on the environment and human health. Ellis’s work is part of an emerging field examining these issues. Over the next year in his lab, he will mimic how the chemicals in fracking fluid interact with shale more than a mile underground. He’s also part of a team of U-M researchers working with stakeholders to study fracking-related issues as they pertain to the state of Michigan. Michigan is one of 28 states that sit on potentially lucrative shale formations.

“I think the question still remains whether or not hydrofracking is a big deal,” Ellis said. “That’s the reason we as a society need to focus on this issue.”

He’s starting that process at a microscope that can magnify 5,000 times.

On the screen, his rock from subterranean West Virginia looks a little like the surface of the moon. As he zooms in, its pores come into focus and it resembles more a satellite view of lake country.

The researchers are measuring these pores, microscale catacombs where natural gas – all that’s left of plants and animals that died hundreds of millions of years ago – floats in the free space or clings to the wall. Calculating the average pore size is a step toward deeply understanding how the rock is structured and what it’s made of.

Ellis points to a bright splotch on the screen.

“Right there, you can see there’s some pyrite,” he says to the student he’s working with.

Pyrite is fool’s gold. It often holds arsenic, which can be poisonous in high concentrations. Arsenic poses no threat underground, but fracking fluid may draw it out and carry it to the surface with the fluid that comes back up the well. (Varying amounts of the injected fracking fluid flow back to the surface. Estimates range from 10 to 70 percent.) The chemicals in fracking fluid may mobilize other potentially dangerous elements too: the heavy metals mercury and barium, as well as the naturally occurring radioactive elements radium and uranium.

Ellis hopes to figure out how this happens.

“We’re perturbing a system on a fundamental level and it’s important to understand what happens after we perturb that system,” he said. “In other words, you just injected a bunch of fluids into the ground and you cracked a rock and now what?”

His work is just beginning. Soon, he’ll make small batches of fracking fluid, soak bits of shale in it, and monitor how the fluid changes. With the knowledge this research could provide, industry and engineers might be able to tweak their recipes to avoid using chemicals that may enhance leaching, he said.

From a policy standpoint, we're making decisions that come before the information we'd like to have.Robert Jackson, professor of global environmental change at Duke University

Why might they want to? Many of the substances Ellis is interested in are among the 51 the EPA is targeting in its study on whether fracking affects drinking water. The EPA chose the substances based, in part, on whether they’re considered toxic. The results will come out in 2014.

The EPA report is one of several major forthcoming studies. Another, expected out later this year, will come from Geisinger Health System. Researchers there are combing through hundreds of thousands of medical records of people who live near gas drilling in Pennsylvania.

For Pennsylvania, these findings will come almost a decade and more than 6,400 shale wells after the first one hit paydirt in the Marcellus there.

The industry, which has received special exemptions from certain federal laws that protect air and drinking water, has grown so fast that experts say science hasn’t been able to keep up.

“What’s amazing is how few papers have been published,” said Robert Jackson, professor of global environmental change at Duke University. Jackson has found evidence of higher methane levels in water wells near active gas drilling.

“It’s partly because of the pace of research. If you follow the rules of the game and send things through peer review, it takes a long time. It means that we’re playing catch up. So from a policy standpoint, we’re making decisions that come before the information we’d like to have. So what else is new? What’s different in this case is the speed with which we’re drilling and plan to drill.”


It's currently unlikely that we will see a lot of new oil and gas development in Michigan in the near future…Johannes Schwank, U-M chemical engineering professor

Karen Fifelski didn’t intend to become an activist at 60 years old. But the call to action came shortly after a man in a pickup rolled up her driveway and asked if she wanted to lease away her mineral rights – his company might be interested in drilling for oil and gas under her dairy farm.

Fifelski had recently seen Gasland, a film about potential risks of the latest gas and oil extraction techniques of hydraulic fracturing and horizontal drilling.

“I said, ‘No, thank you. You can leave,'” Fifelski recalled. “I must have had quite a strong look about me, because he never came back.”

Today, she spends several nights a week at government meetings or gatherings of the fledgling group Michigan Land Air Water Defense (MLAWD), where she is a board member. MLAWD is suing the state over mineral rights leases of public land in Barry and Allegan counties.

“It feels like something I need to be doing,” Fifelski said.

As the number of horizontally drilled and hydraulically fractured, or fracked, wells increases across the nation, so do the ranks of opponents like Fifelski. Michigan is one of 28 states that sit atop potentially lucrative deep shale formations. As a result, over the past few years in the state, fracking has made its way to town meetings, to research labs and to a slowly increasing number of well pads.

Fracturing has been done in Michigan for more than 60 years and 12,000 wells without the kind of environmental damage alleged in other states.Brad Wurfel, communications director for the Michigan Department of Environmental Quality

In a recent University of Michigan poll, just over half of respondents said they believe the benefits of shale gas development outweigh any negative aspects. So while opponents appear to be the in the minority, they are many. Fifelski’s group MLAWD has grown to more than 200 members. And for the second year, the grassroots group Ban Michigan Fracking is gathering signatures for a November ballot initiative to eliminate all horizontal fracking.

At the same time, a team of 10 U-M researchers is working with stakeholders to study fracking issues as they pertain to the state. The U-M Graham Environmental Sustainability Institute’s “integrated assessment” will examine the state’s geology, environment, policies and public perspective, as well as fracking’s economics and potential public health risks.

Industry growing slowly

Out in the field, though, horizontal fracking is still in its early stages in Michigan. It’s been nearly three years since the state’s May 2010 mineral lease auction that netted a record $178 million from companies eager for the rights under public land. Today the number of deep, horizontal, fracked wells actually producing gas in Michigan is three. For comparison’s sake, in Pennsylvania, one company – Cabot Oil & Gas – has 200 wells in Susquehanna County alone.

As of mid-March, Encana, the Denver-based firm that operates all three in Michigan, had six additional wells in development, five more permitted and another six pending permits in the state. Most of the company’s activity has been on state-owned land in Kalkaska County. It is moving into Roscommon, Cheboygan and Crawford.

“It’s very truly exploration at this point,” said Doug Hock, director of community and public relations at Encana. “We know there’s a resource there, but the question is: Can we extract it in a way that’s economical?”


Company officials estimate that if they succeed, they could potentially drill about 500 wells in Michigan over the next several years.

Encana is focusing on the Collingwood shale, also referred to as the Utica-Collingwood. A few years ago, several firms were prospecting in it, but today it’s the only one left. The formation starts at around 8,500 feet down – a mile and a half below the surface. Its potentially productive parts are in the top half of Michigan’s lower peninsula. Encana holds the mineral rights of 432,000 acres of it.

Time will tell if it pays off. Johannes Schwank, a professor of chemical engineering at U-M, predicts that Michigan won’t see significant development until natural gas prices increase and stabilize to between $6 and $8 per thousand cubic feet. That’s about double what they are today.

“It’s currently unlikely that we will see a lot of new oil and gas development in Michigan in the near future, due to low gas prices and the high cost of recovering gas from Michigan’s shale formations,” said Schwank, who is working on a report about fracking technology for the U-M study.

Not your grandfather’s fracking?

It's like comparing a pea shooter with a rifle.Steve Losher, co-founder and president of Michigan Land Air Water Defense

Michigan has a history of gas development that began in 1925. Industry and state officials say fracking has been happening here for just as long.

“Fracturing has been done in Michigan for more than 60 years and 12,000 wells without the kind of environmental damage alleged in other states,” said Brad Wurfel, communications director for the Michigan Department of Environmental Quality. “We’re hard-pressed to identify an industrial process in Michigan with that kind of track record.”

To many fracking opponents, however, the new approach seems a lot different from the old one, in terms of the amount of water and pressure required.

Most of Michigan’s historic gas wells are vertical ones that reach down to a shallow, naturally fractured shale called the Antrim at 1,200 to 2,000 feet. It takes less than 100,000 gallons of water to frack one of them. In contrast, it typically takes five million to seven million gallons of water to frack a deep horizontal well. And Encana has used more than 20 million gallons to frack a well with a 10,500-foot horizontal leg. The well required that much, officials said, because it was so long, but it will drain an area that would take 160 to 200 vertical wells to empty.

In terms of pressure, an Antrim well might need between 2,000 and 3,000 pounds per square inch to effectively push the fluid down, said Jim Peters, operations manager for Northstar Energy. You can buy a consumer-grade pressure washer within that range. To frack a deep shale, you need up to 10,000 psi.

“It’s like comparing a pea shooter with a rifle,” said Steve Losher, co-founder and president of MLAWD, the group that’s suing the state.

Neither type concerns Rick O’Brien, who lives in Gaylord. He’s had two shallow, vertical gas wells on his property for about 13 years. O’Brien hears a lot of talk about the deep fracking happening in his part of the state.

“Just yesterday, I was having lunch at La Seniorita and I overheard two ladies at the table behind me talking about it — how it could hurt our water,” O’Brien said. He didn’t turn around to argue with them, but he did comment to his colleague.

“They’ve been doing this all my life,” O’Brien said, “and the water seems to be okay.”

Getting ahead in Michigan

IMAGE:  Karen Fifelski, board member of Michigan Land Air Water Defense

Encana plans to continue exploring the Utica-Collingwood formation in Michigan with one drilling rig through 2013.

Preliminary reports from the U-M study could come out this summer.

“I think especially in Michigan, we’re almost able to get ahead of the curve in some ways with this concerted effort,” said Brian Ellis, an assistant professor of civil and environmental engineering who is involved in the U-M fracking study. “In many instances, environmental engineers have to come in and fix a problem after it’s happened.

What I've been able to appreciate, I want our kids to see. I want our grandkids to see.Karen Fifelski, board member of Michigan Land Air Water Defense

“As a scientist, I don’t come in with a preconceived notion about whether fracking is or is not a problem,” he added. “But there may be a risk associated with this practice and that is enough to move me to look into it.”

For Fifelski, it’s more personal. She and her family have lived on their hill with a 360-degree horizon for decades. Some of her neighbors have signed mineral leases and that scares her.

“I don’t want to see a well rig right next door to us. I don’t want this land to be ruined. I want our water to stay good,” Fifelski said. “What I’ve been able to appreciate, I want our kids to see. I want our grandkids to see. …I won’t quit.”

Portrait of Nicole Casal Moore


Nicole Casal Moore
Media Relations & Research News Director

Michigan Engineering
Communications & Marketing

(734) 647-7087

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