On a recent morning, Tommy Taylor, a manager with the drilling company Fasken Oil & Ranch, stood in the West Texas desert beside two huge pools of water. One contained freshwater, and the other contained brackish water from the Santa Rosa aquifer 1,700 feet beneath Taylor’s feet.
Fasken has been mixing the two sources as part of a pilot program to use brackish water in hydraulic fracturing, so that the water-intensive drilling process doesn’t deplete local freshwater wells.
“We would like to get to where we’re using 100 percent” brackish water, Taylor said.
In regions of Texas like the Permian Basin, where the water needs of fracking have run up against a historic drought, drillers are increasingly turning to brackish groundwater previously thought too expensive to use. Fracking a well requires roughly 4 to 6 million gallons of water, which gets mixed with chemicals and sand to break up the rock and retrieve the oil or gas. In the Midland-Odessa region, where reservoirs sit 95 percent empty and cities and towns have been under severe water rationing for years, drillers are scrambling to find new sources of water.
A virtual ocean of brackish water lies under much of Texas, but using it carries challenges. It may require the removal of chemical elements that can impede the drilling process by causing problems like scaling (building up sediment in wells), and cities interested in desalinating the water may be competing for it.
Perhaps most importantly, “brackish water is not necessarily available everywhere,” said Michael Dunkel, director of sustainable development for the drilling company Pioneer Natural Resources, in testimony last month before a joint hearing of the House Natural Resources and Energy Resources committees. Some brackish reservoirs also lie deeper than freshwater resources, increasing the costs of drilling a well.
“This [oil] play, the magnitude of it, has taken us by surprise, really. And so we’re all playing catch up,” said Taylor of Fasken Oil & Ranch, which is based in Midland. “We’re working at a feverish pace to try to come up with alternative ways [to drill] and still make good wells.”
Another drilling company, Apache, is already fracking with brackish water from the Santa Rosa aquifer at some of its Permian Basin rigs.
“It has moderately saline water, so it’s not as salty as seawater, but we pump quite a bit of that,” Cal Cooper, Apache’s manager of special projects, said. The company also used “produced water,” meaning groundwater with an even higher amount of dissolved solids that comes to the surface during oil and gas production. Apache mixes the brackish and the produced water together, Cooper said, so “we are able to eliminate the need for freshwater to do hydraulic fracturing.”
Some amount of salt is good, according to David Burnett, a research coordinator at Texas A&M University’s petroleum engineering department, and it can even be better than freshwater.
A recent study on water use for fracking by scientists with the Bureau for Economic Geology at the University of Texas at Austin found that 30 percent of the water used for fracking in the Midland area was brackish in 2011. However, several Permian Basin operators say that figure seems high, especially because use of the mildly brackish water in the Santa Rosa is in the early stages. In the Barnett Shale of North Texas, the study puts brackish water use at 3 percent. And in South Texas’ Eagle Ford Shale, 20 percent of the water used for fracking was brackish. The study was funded by the Texas Oil and Gas Association.“We’re just at the beginning of it, so I think it’s to be determined how far it goes, but I think that brackish water is an important piece,” said Railroad Commissioner Christi Craddick, one of three commissioners heading the agency that regulates the oil and gas industry.
Success in aquifers like the Santa Rosa will not immediately translate into adoption of brackish water by most companies. For one thing, methods of drilling with brackish water would need to be nearly re-invented at each new site.
“Each area has its own different chemistry problem,” says Fasken’s Taylor. “The waters that come back are all different, so out here it’s different than it is in the Eagle Ford, and the Eagle Ford is different than it is in the Haynesville play and the Marcellus.”
The variation in water quality not only means that the water needs to be treated differently, it also means that drillers need to the change the formula of chemicals they mix into the water for fracturing.
“Water is always a local issue, and water quality and water deliverability always changes from one location to another, so there’s a huge amount of variability,” said Apache’s Cooper.
Then there’s the challenge of how that water will interact with different rock formations.
“The problem with this particular water is that it has sulfate in it,” Taylor said as he stood over the Santa Rosa aquifer. If the sulfate combines with barium and strontium — elements that are found in underground water lying alongside underground oil and gas formations — the sulfate can “ruin your well,” he said. His company strips the sulfate out during the treatment process.
Plus, it takes years to determine how brackish water, as well as the water underground alongside the oil and gas, impacts the long-term viability of an oil or gas well.
“It’s an exercise in chemistry on one side, and on the other side is economics,” Taylor said. In some areas, he said, brackish water may not be cost-effective.
Despite those roadblocks, West Texas drillers remain optimistic about brackish water’s potential to alleviate the water shortages. Its promise has also drawn in local cities, which are interested in desalinating it for drinking purposes.
“It’s kind of a one-two punch,” Odessa City Manager Richard Morton said. “This drought, in time, probably is worse than the 1950s drought. With the expanded oil and gas activity combined with the drought, we’re seeing more and more people come in to service the oilfield. Those people require water to live and to do business in this community.”
Odessa is exploring tapping the Capitan Aquifer, a brackish aquifer about 80 miles away. It plans to treat that water and pipe it to Odessa, creating a much-needed supply.
The notion that both cities and drillers may compete over brackish resources has raised concerns.
The study by UT-Austin’s Bureau for Economic Geology noted that “use of brackish water in areas with limited fresh water supplies could compete with conventional users.”
In the February House hearing on water use drilling, state Rep. Lyle Larson, R-San Antonio, suggested that drilling companies should share data on where they have explored for brackish water with local water districts.
Communities are “going to be searching for that sometime in the future,” Larson said.
Morton, the Odessa city manager, views the drillers not as competitors, but as a potential water customers. Financing from interested drilling outfits, he says, could help the city develop its brackish resources.
“Use of the oilfield as a customer may actually help pay for the development of the brackish for residential use,” he said.
Kate Galbraith contributed reporting.