Devon pushes the water recycling envelope

Texas A&M’s Burnett says effort makes economic, environmental, societal sense

BY STEVE QUINN FOR GREENING OF OIL

Producing some of the cleanest energy can still be an especially dirty job.

That’s the rub as oil and gas companies unlock natural gas in shale fields made up of tight rock formations while generating millions of gallons of wastewater.

(Start the conversation. See comments section at bottom of page.)

For now, it’s a divide that pits industry proponents and landowners looking to lease their property against opponents seeking more accountability.

Once out of reach, the shale gas is now economically accessible, but the industry is catching up with technology capable of reducing the footprint from extracting fossil fuels.

Devon Energy said it has been able to recycle a small percentage of the nearly 4 million gallons of wastewater produced per well in North Texas’ Barnett Shale.

In three years Devon, the lead developer at the Barnett Shale, has recycled nearly 400 million gallons of wastewater, enough to drill 100 wells.

What this means is ultimately less water gets disposed and less freshwater gets used, which is especially important in the drought-prone North Texas region.

‘Just the beginning,’ says Texas A&M’s David Burnett

Even though it costs more than most disposal methods, recycling wastewater leads to good public policy and perhaps is the start of greater efforts, said David Burnett, director of technology at Global Petroleum Research Institute at Texas A&M University.

GPRI and several partners are being funded by the National Energy Technology Laboratory to develop a mobile technology for pre-treating used water. The pilot tests will focus on the Marcellus Shale in New York, Pennsylvania and West Virginia.

Burnett is also a founder of Environmentally Friendly Drilling, which is an industry and government funded program to identify sound technological drilling practices and to endorse them.

“Access to freshwater is going to be less and less,” Burnett said. “If you’re Devon, you don’t want to compete with municipalities and public for water sources.

“What the industry is trying to do is reduce the handling of the water. Many times they have to truck it out or pipeline it out.”

‘Pushing the envelope’

Jay Ewing, Devon’s manager of well completions in the Barnett Shale, said the Oklahoma City-based company and its recycling partner Foundation Quail Water Management has just begun “pushing the envelope.”

“It’s a continuous process to increase the efficiency, reduce the cost of the process, plus expand the amount of water that we can recycle,” Ewing said.

Companies know how to get even the hardest to reach gas with a method called hydraulic fracturing, also known as fracking.

This calls for blasting water with sand and chemicals into the shale to crack rocks and release the gas.

Ewing estimates that 250,000 gallons of water daily get recycled. Devon recycles up to 16 percent of the freshwater used.

For example, if it takes 100 gallons freshwater to drill a well, about 20 percent of that water is returned and Devon is able to recycle about 16 gallons.

Here’s how it works:

After wastewater is removed during the shale fracturing, the water receives an additive that allows the finer particles to congeal and settle at the bottom.

The suspended solids as well as the congealing additive get removed and are disposed in a landfill.

Salt gets separated by boiling, vaporizing and distillation. That salty concentrate can help Devon with additional well completions.

The distilled water is then returned to the field and gets reused for more shale fracturing.

For now Ewing said Devon and its partner Fountain Quail are able to recycle what’s called “flow back” water.

That’s water that goes in fresh but collects impurities, such as a low concentration of chlorides.

Water known as “produced,” however carries a higher dose of chlorides and is often originally part of the rock.

This pool of water can also be recycled, but not with the same cost-effectiveness, Ewing said.

Recycling costs about 40% more

Recycling costs about 40 percent more than many disposal methods, but Ewing said it has long-term value when companies begin developing other shale fields like Marcellus in West Virginia, Pennsylvania and New York.

“We can see that in the future that is going to be something that is going to be needed,” Ewing said.

“Freshwater is a commodity needed by everybody; it’s going to be greater in some other areas, so we need to be working on ways to reduce our demand.

“There are shale places, particularly in the Marcellus, that don’t have that same amount of freshwater at their disposal.”

Hydraulic fracturing has been around for nearly 60 year, but only became contentious recently as it became crucial to developing shale fields.

In other fields such as Marcellus, water management has become highly divisive as state regulators and lawmakers debate regulations for these areas.

In January, landowners supporting regulations to lease mineral rights for the deep reserves and environmentalists in Albany, N.Y., sparred.

“It’s an issue for all gas fields,” Ewing said, “So you had better be working on the technology before the legislation.

There’s the lab, and then there’s the field

“We’ve had 60 companies say, ‘I’ve got the technology and I can recycle your water.’

“We say, ‘let’s put it in the field. Let’s run a test.’ It’s trial and error.

“It works in the lab and works with small units. But let’s run 100,000 gallons through in a 24-hour period in the field. That’s what industry needs to be doing.”

Meanwhile, in Washington D.C., federal lawmakers are considering a bill that would require companies to identify chemicals used in hydraulic fracturing.

More regulations could negate a merger deal recently announced by North Texas companies, Exxon Mobil Corp. of Irving and XTO Energy of Fort Worth.

Ewing said emerging technology is always on the horizon, citing developments that allowed Devon to become the lead developer in the Barnett Shale.

For years, oil and gas explorers sought ways to economically produce gas from the North Texas fields.

It took combining a pair of developments to make it work: hydraulic fracturing and the use of horizontal drilling.

This too, helped reduce the footprint of fossil fuels on the earth’s surface.

Companies first drill straight down and then across, to extract gas from one well over a large area, rather than having to drill four or five separate vertical wells.

Why ‘the whole industry is going green’

Burnett said the industry’s efforts have a three-fold motive: economics; environmental veracity and meeting societal demands.

“None of these are really congruent,” he said. “The cheapest way isn’t always the best way; the most environmentally friendly isn’t always the most affordable. And societal issues won’t always allow you to do what you want.”

Burnett added that the public should not underestimate the industry’s drive to improve technology, especially as the resources become tougher to access.

“When you have a tremendous expense and the preoccupation the industry has with developing the resources, you’ll find a lot of people trying to solve the problem,” he said.

“There are several ways technology makes advances,” he said. “You want problems to be solved, but you want the correct problems to be solved.

“This helps companies make a profit; it helps the environment; it benefits society as a whole. That’s why the whole industry is going green.”

Links of interest

Devon Energy

Global Petroleum Research Institute

National Energy Technology Laboratory

Contact Steve Quinn at smqwrite@gmail.com