Thursday, January 24, 2013 at 6:08 PM
As drilling expands in Ohio’s Utica shale, many critics have concerns about the method used to extract natural gas. They worry that the fracking process generates an inordinate amount of wastewater laced with toxic chemicals that are dangerous to human health. But a new research study lends a different perspective on all of that waste. Ideastream’s Michelle Kanu reports.
The hydraulic fracturing—or fracking—process involves pumping millions of gallons of water, sand and chemicals into underground rock formations to release the gas trapped there.
Once the gas is freed, some of that water comes back up to the surface.
Exactly how much is still unknown, and that’s what got Kent State biogeochemistry professor Brian Lutz and two colleagues from Duke University started on their research project.
Lutz says they focused on nearly 2200 wells drilled in Pennsylvania between 2004 and 2011. They compared the amount of waste water generated from conventional vertical wells drilled into sandstone to the waste from horizontal wells that are drilled into shale.
Lutz: “We found that shale gas wells produce 10 times more waste water than conventional wells, but they also produce 30 times more natural gas than conventional wells. And so when you put it into a per unit gas ratio, shale wells are only producing one third the amount of waste water for every unit of gas recovered.”
In other words, Lutz says, shale wells are a better bang for the buck in the long run.
But, he points out, as shale drilling increases, the volume of waste water those wells produce could eventually overwhelm our ability to dispose of it.
Lutz: “The waste water volumes are growing so fast that we have to have solutions for waste water in front of development because we can’t post hoc deal with this waste water stream.”
Currently, Ohio uses primarily injection wells to store its own fracking waste water. Those wells also and accept waste from other states.
The study was published in the journal Water Resources Research.