Keeping hydrocarbons flowing from the Permian Basin requires solutions for produced water, sustainable approaches, and technological innovation.
During a 19 June special session focused on the future of the Permian Basin at the Unconventional Resources Technology Conference (URTeC) in Houston, panelists called for holistic produced-water solutions to ensure the basin’s sustainability.
Cody Comiskey, subsurface adviser for water and seismic with Chevron’s Mid Con Business Unit, said seismicity across the Permian has expanded, although a reduction in disposing of produced water in deep wells appears to be helping reduce frequency of magnitude 3 and higher earthquakes in the area.
Until around 2009, there was only a “spattering” of seismicity in the basin, typically with fewer than a dozen earthquakes in any given year, he said. But, in 2021, 192 were recorded in the basin. In 2022, 222 were recorded.
“2023 was the first year to show a decline in seismicity since they started to increase in 2015,” he said, noting there were 200 recorded quakes that year. “There’s still a significant number of earthquakes, so it’s still a very large issue.”
Not only has there been an increase in recorded earthquakes, but the magnitudes have grown as well, Comiskey said.
“Our ability to understand and monitor has increased significantly,” he said. “This is not an individual operator’s issue. … This is really an industry issue.”
But the problem is complex because the deep disposal wells in depths of 8,000–10,000 ft thought to be a factor in the increased seismic activity are typically not “right on top of” the earthquake, he said, and injection of water can increase reservoir pressures, even across long distances.
“A few psi change can induce slip” of faults, he said.
On the other hand, injecting produced water into shallower wells doesn’t seem to affect seismicity, he said. They are, however, filling up quickly.
“We have to look at produced water holistically,” he said.
And, in the Permian, there’s a lot of produced water.
“We need optionality in the Permian,” Comiskey said. “If you’re looking at this much water, we need options to handle it.”
Brian Bohm, environmental sustainability manager at Apache Corporation, said the industry may have addressed the produced-water-induced seismicity issue by shifting to storing water in shallower disposal wells.
“The seismicity issue seems to be getting better, but we’ve changed the problem” so that drilling now goes through the disposal zone, he said, noting drillers “don’t love drilling through that.”
While the industry has sent the vast majority of produced water “down another hole,” it should have seen anticipated seismic events in the Permian at some point, he said, based on seismic activity increases in other basins with injection wells.
Options for handling produced water include recycling and reusing the water, he said, but other solutions also are needed.
Between produced-water disposal and storage of captured carbon, “We are going to start fighting for reservoir space in the Permian,” he said.
One goal oil and gas companies should pursue is being water positive, he said.
According to Wikipedia, the goal of being water positive “is to leave a positive impact on water ecosystems and ensure that more water is conserved and restored than is used or depleted.”
One potential reuse of produced water, Bohm said, is for irrigation, which needs more water even than the Permian produces.
If the water can be treated well enough, it could be a partial offset to irrigation needs, he said.
Ideally, he said, produced water would be treated to fit the purpose of the reuse rather than it all being treated to drinking-water standards.
“The idea is to do fit-for-purpose treatment—remove what’s needed, find a beneficial use for it,” he said.
He said the treatment capabilities exist.
“It’s just economics and regulation,” he said.
Angela Bedoya, net-zero development manager at Occidental, said direct air capture (DAC) of carbon is a water-hungry process.
“DAC needs a lot of water,” she said.
Oxy subsidiary 1PointFive is building Stratos, a large DAC facility, in the Permian. It’s designed to capture up to 500,000 metric tons of CO2 annually when fully operational. That project is one of many Oxy is pursuing on the path to a low-carbon world.
Bedoya said the company has folded emissions forecasting into its field-development planning workflow and incorporated carbon data as a key metric for each field.
“Doing so has changed the way we develop our fields,” she said.
Oxy’s Permian fields of the future will rely on various strategies to lower carbon intensity, she said. The operator has also developed a CO2 baseline for all of its facilities, whether brownfield or greenfield developments.
“We see the impacts of optimization as we move toward net zero,” she said.
Some of the strategies include electrification where possible, zero routine flaring, and optimizing use of leak detection and repair processes to improve response time to leaks, she said.
Nuny Rincones, reservoir engineering innovative solutions manager at ConocoPhillips, said technology such as artificial intelligence (AI) will help the operator gain efficiencies with its Permian developments.
AI will speed up optimization of fields, she said, but first, the data has to be modernized.
“Innovation happens in many phases,” she said.
The efficiencies that AI can deliver will help not just with discoveries but also with “getting better at extracting the barrels you already have,” she said.
