A company that makes systems for algae growth and harvesting has repurposed its machines to tackle flow-back water from the oil-and-gas industry. The water-separation technology, which recently completed successful testing in Bakersfield, Calif., uses electricity, instead of chemicals.
“The energy cost is low, on the order of 0.14 cents per barrel, which doesn’t include labor,” says William Charneski, senior vice president at OriginClear Inc., Los Angeles. A March 2015 report by Pacific Advanced Civil Engineering, Fountain Valley, Calif., projects the system's operating costs, including labor, to be $0.43 per barrel. According to a 2013 U.S. Dept. of Energy report, this cost was, at the time of the report, well below the average for haulage and disposal costs, which were then $1.47 per barrel in the southwestern U.S. and $2.10 per barrel in the eastern U.S.
The technology uses a filtration system called electro water separation (EWS), which employs electrochemistry to separate the flow-back water from the oil and chemicals used in hydraulic fracturing. In the same way, EWS can treat produced water from conventional oil and gas wells, says Charneski.
The EWS process uses electro-coagulation, in which fracking water passes through a reactor, where the oil-water emulsion—as small as 1 micron and up to 25 microns—is broken up by electrical pulses. The process also kills bacteria, notes Charneski. The water and the suspended solids and oils flow into a flotation chamber; there, an electrode array generates bubbles which attach themselves to the suspended oil-chemical particles and float them to the surface; then, the particles are removed from the water.
For management of "produced water," which is the new water pumped out of the ground during the operation of oil wells, the biggest competitor to this type of technology is underground disposal, says Eric Burkhart, managing director of corporate business at Total Western Inc., Bakersfield. Underground disposal of produced water has been standard practice in the U.S. since the oil-and-gas industry started, he says. “However, due to increasing regulations and extreme water scarcity in the central California region, treatment and reuse of the waters, rather than disposal, is becoming necessary,” he says.
Burkhart’s company did a feasibility study for a client, investigating whether the produced water from oil wells could be treated to enable on-site reuse in the production process as boiler feed or for irrigation purposes, he says.
“The total treatment time for the OriginClear EWS system we tested was between 15 and 20 minutes, and [it] was able to completely treat the water for reuse. That treatment-time reduction, to achieve a higher quality that enables reuse rather than disposal, translates to better economics,” Burkhart says.
Charneski claims none of the competition can get water as clean as EWS can. "The other processes can’t handle [a] 1- to 25-micron-size droplet. They simply pass through whatever other competitive processes are out there,” he says.
According to the most recent report from California’s Dept. of Conservation, oil wells in the state pumped 3.1 billion barrels of produced water out of underground reservoirs in 2013. Much of this remains unused in the underground disposal tanks, says Burkhart.