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Committee studies oil-field water use in Oklahoma
Technology, regulatory changes and a bit of creativity will be needed to convert one of the state's bigger liabilities into a needed resource, members of the Water for 2060 Produced Water Working Group said Friday.
The group has spent more than a year studying how to best handle the water produced along with oil and natural gas throughout the state.
"This effort is unique in that we brought in the water-use sector as well as the industry sector and regulators," said Julie Cunningham interim executive director of the Oklahoma Water Resources Board and chairwoman of the Produced Water Working Group.
"Groundwater and produced water are not the same statewide. Recognizing that and trying to fit the use and treatment spatially is something unique to this group."
Gov. Mary Fallin assembled the group in late 2015 to take a long-term view of produced water in the state. Produced water refers to the ancient water that is recovered along with oil and natural gas production. Sometimes called fossil water, the remnants of ancient oceans typically are many times saltier than seawater and sometimes include metals, chemicals and other hazardous elements.
Oil and natural gas companies historically have pumped that water deep underground in disposal wells, but researchers and regulatory say that process has caused the state's earthquake swarm over the past few years.
Regulations to address the earthquakes have restricted how much water can be disposed in the Arbuckle rock formation. The produced water working group is tasked with finding better ways to use the water in combination with the group's broader goal of helping the state use no more water in 2060 than it did in 2012.
Moving water
The preliminary report focuses on two processes that are used today - disposal and recycling for use in nearby hydraulic fracturing operations. It also looked at eight more expensive options, including piping excess water from the high-water Mississippi Lime in northwest Oklahoma to the less water-intensive STACK formation in central Oklahoma.
"There is going to be a need for additional water in the SCOOP and STACK as oil and gas drilling ramps up again," Cunningham said. "Transportation is expensive, and building a pipeline is expensive. But that's certainly an option that jumps out."
Other options include evaporating the water and disposing of the elements left behind and cleaning the water to the point that it can be used for power generation or other industrial uses.
Those options require technical, process and regulatory changes before they would be cost-effective and practical on a large scale, said Michael Dunkel, vice president at CH2M, which helped write the report.
"There are commercial complexities and technical issues," Dunkel said of the option to pipe produced water from Alfalfa County to Blaine County. "More research is needed to know if this is doable, but we're saying that based upon the costs, this is possible."
The pipeline and evaporation options are seen as being among the best short-term options. The other options are more expensive and are seen as longer-term answers.
"This is not a solve-today problem," said Michael Teague, Oklahoma Secretary of Energy and Environment. "We don't need to do it today. We need to be able to do it by 2060. We're looking at what we can do in the short run to set us up for the long term. There are near-term things we should be looking at now."
Next steps
Committee members on Friday debated fine points of the report, including the best way to calculate and display costs involved in the various produced water use scenarios. Following updates and the release of the final version, committee members said they will continue their efforts to promote the use of produced water throughout the state. The group also is applying for grants and other funding sources to continue the research.
"We're trying to find the dollars and partners to get some of those key questions answered that would be potential barriers for water use," Cunningham said.
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