Reusing oilfield water

Researchers seek solutions to water scarcity

Water is scarce in Southeastern New Mexico, and as demand increases for freshwater, there is a need for alternative water sources.

Faculty and staff from New Mexico State University and the New Mexico Water Resources Research Institute joined researchers from around the state last year for a feasibility study on the reuse of produced water. 

One of the most relevant findings from the study is that the most feasible use of produced water generated from the oil and gas industry is for that industry to reuse its own produced water, instead of using freshwater.

Robert Sabie Jr., geographic information systems analyst for NM WRRI, said this cost-effective solution would allow freshwater to be reserved for drinking water.

“Also, agriculture doesn’t require the same standards as drinking water, so essentially we might be able to offset some of that water use and create a longer, more sustainable aquifer,” Sabie said.

Kenneth “KC” Carroll, associate professor of water resource management in the NMSU Department of Plant and Environmental Sciences, said the oil and gas industry in West Texas and Southeastern New Mexico produces large amounts of water. With water shortages in that area, it’s important that researchers identify alternatives to purchasing fresh water from farmers and to reinjecting produced water into the subsurface as a wastewater.

Sabie, project manager for the study, said it’s a good sign that the oil and gas industry is reusing produced water more and more. That helps the industry cut high costs of transporting, treating and injecting the water into designated injection wells. By reusing their own produced water, companies are able to use less costly and semi-mobile regulated treatment plants closer to the oil and gas extraction areas.

WRRI Director Sam Fernald was principal investigator. NMSU collaborators included Carroll, as well as Pei Xu, associate professor of environmental engineering in the NMSU Department of Civil Engineering.

“We need to find an engineering solution to solve the problem,” Xu said. “My job was to investigate the treatment technologies and the cost to treat the water.”

She’s working on the ongoing project with assistant professor Yanyan Zhang, evaluating environmental toxicity of produced water and treatment needed to reduce toxicity and ensure safe reuse.

Carroll studied how hydrogeologic or geologic formation variability – how deep and which rocks the water comes from – will affect the produced water quality. He also researched the spatial variability of the produced water quality and the chemical composition of water in the Permian Basin formations that is being pumped to the surface.

“In addition to salinity variations, we found quite a bit of variability in the type of salts dissolved in the waters,” he said. “We also discovered that a significant amount of water migrated deep into the Basin from the land surface, which enhances our understanding of the water flow behavior in deep subsurface basins like the Permian.” 

The study helped establish a clearer picture on the regulatory framework, Sabie said. Three state agencies were regulating water, so researchers helped them iron out details for a permitting process.

The study included researchers from Los Alamos National Laboratory, New Mexico Institute of Mining and Technology and New Mexico Energy, Minerals, and Natural Resources Department. Funding was provided by the Environmental Protection Agency through the New Mexico Environment Department.

Shown in his lab with former graduate student, Adam Dettmer, left, Kenneth “KC” Carroll, associate professor of water resource management in the NMSU Department of Plant and Environmental Sciences, is one of the researchers studying various aspects of oil and gas industry produced water in Southeastern New Mexico.