Projects recycle oil field wastewater
Pilot efforts aim to cheaply purify brine to reduce disposal, bolster irrigation supply
Freshwater resources in West Texas are dwindling at the same time the oil country is struggling to dispose of dirty, unwanted oil field wastewater that is spewing from leaky wells and triggering earthquakes. It’s a dual challenge that an emerging industry is working to solve.
New pilot projects in the Permian Basin of West Texas and southeastern New Mexico are testing technologies that they hope can cost-effectively purify the chemical-laden brine that flows up alongside oil during the production process so it can be reused. Regulators and oil companies are heavily involved as they aim to usher in a new era of oil field wastewater recycling.
The premise is nothing new — some of this wastewater is already recycled for reuse in fracking. But efforts to recycle billions of barrels of water are gaining new momentum as the Texas Railroad Commission cracks down on underground wastewater disposal in areas of intensifying earthquakes, leaving oil companies with fewer places to put it.
Meanwhile, arid West Texas and New Mexico are looking to bolster freshwater supplies and increasingly see opportunity in treating the oil industry’s wastewater, also known as produced water, for reuse in irrigation, for the production of new fuels such as hydrogen and to recharge drying bodies of water such as the Pecos River.
The practice of recycling this water is gaining traction out of necessity, said Mike Hightower, program director of the New Mexico Produced Water Consortium.
“I think within three years we’re going to see (recycling efforts) start exploding,” he said, noting that Texas alone needs to come up with 7 billion gallons of new water a day by 2050 to address a growing gap between freshwater supply and demand.
And because regulators and hydrogeologists believe that wastewater underground is correlated with a rash of earthquakes shaking the oil country as well as a worrying trend of water returning to the surface through old wells, “we can’t continue to inject like we do.”
“Why am I bullish? I need to be.”
Wastewater handling is an essential part of the oil production process, especially in the Permian, where five to nine barrels of super-salty water laced with
chemicals can come up with a single barrel of oil. This flowback is a mix of the water used to frack the well and water trapped with oil in rock released by the production process.
Without places to put the water or recycling facilities capable of treating it, oil companies could be forced to stop extracting oil in some areas of the oil-rich basin. It’s a growing threat, given that earthquakes in the area are still trending “alarmingly high,” said Ryan Hassler, vice president of oil field service research at Rystad.
“What’s at stake at the worst end of this is having to shut in drilling and completions activity,” Hassler said.
The trick is getting regulators to set new standards for treating the oil field wastewater and bringing the cost of recycling technology down to a point where it’s competitive with disposal, researchers said. To that end, there are eight active pilot projects feeding fresh data to regulators and industry consortiums.
Until there are clear regulatory guidelines on how to process the water, oil companies remain reluctant to invest in recycling facilities, Hassler said. The recycling units could cost as much as $30 million a piece, according to Joe de Almeida, Occidental Petroleum’s director of water strategy and technology, who spoke during a recent conference in Houston hosted by the Produced Water Society. To make the investments, Oxy would want to know more about regulators’ expectations.
In response to industry hesitance, the Railroad Commission’s chief engineer, Ted Wooten, assured the conference’s audience that it would be up to the industry to do the research needed for standard-setting.
“We will help implement what you establish as reasonable and good practices,” Wooten said. “But you have to do that publicly, because we have to have public trust in what you say.”
Produced water often contains benzene and other potentially harmful chemicals, so pilot projects underway are working to prove they can filter out chemicals of concern as well as desalinate brine to standards that would be accepted for various purposes.
A pilot project south of Midland by Texas Pacific Water Resources uses a proprietary multistep process involving pretreatment, desalination and reverse osmosis that pulls heavy metals and other toxic elements from water, removes salts and produces water clean enough to sustain crops, said Adrianne Lopez, the company’s technical research and development manager. Crops appeared healthy after six months of study, and preliminary results were positive, she said.
Alfalfa is a good crop to study because it can tolerate more salt than many plants, it is a profitable crop that could offset recycling costs, and it can absorb more water than many plants native to dry West Texas, making it a fit for an industry looking to dispose of water through irrigation rather than underground disposal, Lopez said.
“An alfalfa field will uptake quite a bit of water,” she said.
Desalination is expensive, which poses a technical challenge for water as salty as this, which often requires multiple rounds of desalination before it can be reused.
“That’s obviously what a lot of these pilot projects are working towards, trying to figure out new technologies and ways to do this at scale,” Hassler said. “Nobody’s been able to crack the code at scale, so there’s a lot of different approaches that are being tried.”
A separate project from Circle Verde Water in Coahoma uses high-pressure natural gas to filter water in one step — a process the company believes would be cheaper and more energy efficient.
How is it doing that? Circle Verde CEO Joseph Alexander was coy in his answer, citing pending patents: “That’s kind of a secret.”