With produced water volumes expected to surge in the coming years, focus moves towards non-traditional water management options.
One of the best-attended sessions at the Produced Water Society’s 2020 Seminar was the ‘R&D Needs’ panel discussion, which largely centered on where to place the massive volumes of produced water that are forecast in the Permian Basin.
RI Holdings water treatment CTO Brent Halldorson explained that the industry was currently experiencing a water deficit during which produced water recycling can be done with ease. However, a time will soon come when the industry faces a water surplus and reuse outside of oil & gas will be necessary.
“We may think we’re 5-10 years away from that water surplus, but a major impact on oil & gas prices could take us there tomorrow,” Halldorson cautioned, describing how low gas prices had led to severe water management challenges in the Marcellus play.
Several panelists noted that not much new research is required for water recycling within the oilfield; however, there is an urgent need to look at beneficial reuse options in other industries.
Joe de Almeida, Occidental Oil & Gas Corporation’s director of water strategy, said that concentrating produced water to near saturation – about 300,000 total dissolved solids (TDS) – could simultaneously relieve disposal constraints and free up large volumes of water for applications such as range management or non-edible crop irrigation.
“The technology does exist today to do what I’m talking about, but not cost effectively,” he told the audience. “If we’re going to talk about technology that [costs] $1.50-2.50/bbl, we’re dead in the water before we start. The key in this R&D need is cost-effective technology.”
He added that the recently formed New Mexico Produced Water Research Consortium will have an important role in R&D for beneficial reuse. One of the categories the consortium will investigate is water quality characterization, which is key for regulation setting.
Several participants in the discussion brought up the difficulties of overcoming resistance to beneficial reuse on the part of the public and operators’ risk-averse legal teams.
Lisa Henthorne, Produced Water Society president and Water Standard senior vice-president and CTO, commented that there were challenges in adopting reuse of other treated wastewater streams in the past, but those had been overcome through creative and proactive thinking. Water Desalination Report editor Tom Pankratz emphasized that point, saying that “people are gradually getting used to the concept of water quality being more important than its history.”
More transparency could help the industry garner public trust and reduce hurdles for the R&D community, such as opacity when it comes to compositional data on produced water. Peter Fiske, executive director of the National Alliance for Water Innovation (NAWI) research coalition, told the audience that he would like NAWI to be “a neutral repository for compositional data from every major play so that researchers can understand how they should be guiding their research to address contaminants that are actually present.”
Other ideas for how to manage the produced water include fractionation to recover high-value ions such as lithium. John Wind, former R&D chemical engineer at Sandia National Laboratories, said that could improve the economics of the advanced processes required and transform the water from a waste stream into a resource.
The potential to recover salts such as sodium and calcium chloride was also mentioned, though some panelists agreed there probably wouldn’t be a suitable market for those products. “The market [for salt] is extremely flush,” de Almeida said. He added that the amount of salt that could be extracted from 100,000 bbl/d of produced water – just a fraction of volumes produced in the Permian Basin – “would be enough for a world-class chlor-alkali plant in middle of nowhere with really costly logistics, and the world doesn’t need another chlor-alkali plant.”