Reconsidering fracking waste water

Fracked wells in West Texas don’t just produce petroleum. Much more than anything else, they spit up salty, mucky water.

Typically, companies have discarded that fluid, hundreds of millions of gallons per day, by injecting it back underground. But as water becomes more scarce, they’re beginning to reconsider.

For now, hydraulic fracturing in arid West Texas uses large amounts of fresh aquifer water to crack open subterranean shales, unleashing a mixture of oil, gas and fossil brine 10 times as salty as the sea.

Increasingly, frackers are starting to reuse that brine, easing their burden on aquifers.

“We’ve just month-by-month seen extraordinary growth in the volumes we are managing,” said Matthew Gabriel, CEO of XRI Holdings, which recycles oilfield wastewater in the Permian Basin, the nation’s top oil producing region.

This month, XRI announced a 230-mile expansion to its existing 450-mile Permian pipeline network.

Unlike other Permian pipelines, these carry water from oilfields to treatment plants and back, linking the major oil producers’ batteries of tanks. XRI, based in Houston, is also adding three more treatment plants to its existing 30.

Fracking doesn’t require particularly clean water, and the treatment to prepare it is pretty simple, Gabriel said. It’s the pipeline network that makes it economical, providing the equivalent of oilfield plumbing to replace the laborious process of trucking in water and trucking out waste.

“You open a valve and you can have all the water you need,” Gabriel said. “I think we’re going to see enormous advances around this concept in the coming years.”

XRI manages 1 million barrels of wastewater per day and recycles 800,000 — a small portion of the total volume produced by Permian Basin oil fields in that time.

Recently, Texas convened water experts for a state-funded study of recycling that so-called “produced water” (wastewater from oil wells). Released this year, the Texas Produced Water Consortium report estimated Permian Basin wastewater production at approximately 11 million barrels per day, nearly 4 billion per year in 2019, the last year of available data.

The figure has likely increased since then in step with soaring Permian oil and gas output.

In response to a survey by the Texas Consortium, fracking companies on average said they were already reusing about 30% of their wastewater.

Even if they satisfied 100% of their need with recycled water, they would still have millions of barrels of produced water left over every day.

Underground disposal remained a much cheaper option than reuse, it said, but might not be so for long.

“Scarcity conditions,” said the 130-page report, “will eventually make this an economically viable option.”

According to the latest Texas water plan, statewide supplies will decrease by approximately 18 percent within 50 years, “primarily due to depletion of aquifers.”

“Without additional supplies... one-quarter of Texas’ population would have less than half of the municipal water supplies they will require in 2070,” the plan said.

Managed depletion

Fears hit especially hard in the state’s western desert and plains, where fracking is booming. Almost 80% of this vast region’s documented water demand is met by a complex collection of aquifers, the colossal subterranean formations that filled up over millions of years.

“We’re just planning to deplete it. It’s not like we’re conserving it. We’re just making the crash landing slow and somewhat tolerable,” said Jeff Bennett, a hydrogeologist in the small town of Alpine who worked for15 years for the National Park Service nearby.

Planners called it “managed depletion,” the intentional use of the resource to its end.

Such a fate awaits the Ogallala Aquifer, the nation’s largest underground body of water, which swoops into West Texas from the north, and for which the Texas Water Development Board calls “managed depletion” its “management strategy.”

Models suggest people are drawing from the Ogallala at 6.5 times its recharge rate, according to Robert Mace, executive director of the Meadows Center for Water and the Environment at Texas State University in San Marcos.

“It’s like a savings account. Your paycheck is $1,000 per month and you’re spending $6,500 per month,” he said. “You came in with some money from grandpa and that balance is just going down.”

The figures come from complex models informed by partial, self-reported water-use records collected by a patchwork of groundwater districts.

Atop the Pecos Valley Aquifer, which underlies much of the fracking heartland, five adjacent counties lack groundwater districts. In one of them, Winkler County, the TWDB expects aquifer levels to fall by up to 161 feet between 2010 and 2070.

“Nobody is managing it,” Mace said. “You pump whatever you want, you do whatever you want.”

He said models expect the Pecos Valley Aquifer to support demands through 2070, but not indefinitely.

“How did you go broke?” Mace said, quoting Ernest Hemingway. “Gradually, then suddenly.”

Of 883 active water wells registered with the TWDB on the Pecos Valley Aquifer, 237 are for livestock, 209 for irrigation and 131 for public supply.

Another 146 are for industrial use. These wells may serve a variety of processes, from power generation to chemical refining. Many provide water for the fracking process, registered to owners including BP, Sinclair Oil & Gas, Exxon Mobil and Gulf Oil.

Fracking water

It’s impossible to know exactly how many water wells are used for fracking or how much they pump because the Texas Water Code exempts oil and gas producers from reporting and permitting requirements.

The U.S. Geological Survey has estimated freshwater consumption for fracking in the Permian Basin of Texas grew by 2,400% between 2010 and 2019, to 72 billion gallons, approximately one-and-a-half times the amount of water used by the City of Austin that same year.

Fracking uses about 16 million gallons of water per well per year in the Permian to break open underground shales that hold oil, gas and — mostly — super-salty water, the buried remnants of ancient oceans. Freshwater goes down the well, and more than twice its volume of brine comes back up, mixed with the hydrocarbons.

The Texas consortium report estimated 3.93 billion barrels of Permian fracking wastewater in 2019, a year when the whole basin produced 1.4 billion barrels of oil.

Some of the water is reused in fracking, but the large majority is pumped underground and discarded. Planners have considered treating it to irrigate crops instead, which California does with wastewater that is much less salty and doesn’t include fracking fluids. But for now, that remains a high-tech ambition with the much dirtier Permian water.

Reuse in fracking

Unlike farmers, oil producers can reuse their dirty effluent without intensive purification or health concerns over toxic constituents. The industry has identified the benefits of doing so.

“Not only does produced water recycle and reuse offset the need for fresh water for fracturing operations, treated produced water works better than fresh water,” read a 2019 white paper from the Texas Alliance of Energy Producers. “Reuse is likely to increase as the midstream industry matures and injection capacity is unable to keep pace with production.”