By Timothy Puko
The Pittsburgh Tribune-Review
Industry experts call it continuous innovation: Drillers are replacing harsh chemicals with benign substances when fracking and someday soon might not need water to crack deep shale formations for natural gas.
Propane, carbon dioxide, nitrogen, helium and water from abandoned mines or the sea are gaining a place alongside fresh water as companies work to improve the process of hydraulic fracturing, or fracking, and lessen risks to people and the environment, experts say.
Companies are experimenting with methods to replace water in part or entirely, or are tweaking the mix of water and chemicals they pump underground.
“Whatever chemical is being used out there, they want to make sure it’s good in the public eye, good for the growth of their company,” said Kevin Schwartz, a salesman at the Leetsdale offices of Weatherford International Ltd., an oil- and gas-field services company. “They want to be on the chemistry forefront.”
Most notably, companies are phasing out the use of solvents with chemicals from the BTEX family — benzene, toluene, ethylbenzene and xylenes — that can cause cancer or brain problems, Schwartz said. Drillers are using ultraviolet light instead of chemicals that kill organisms to eliminate bacteria that can build when sinking wells.
“This new approach will be tested here” in Pennsylvania, said Radisav D. Vidic, a University of Pittsburgh civil and environmental engineer.
“It certainly helps to use benign chemicals in terms of workers’ safety on-site, as it reduces the potential for accidental exposure and harm. It also reduces the potential for environmental damage due to spills from storage reservoirs and will likely put to rest the concerns about groundwater contamination during fracking,” Vidic wrote in an email.
“[This] is a story of continuous innovation,” said Andrew Paterson, a technical expert with the Marcellus Shale Coalition, a trade group. “As people learn more, and people who are willing to experiment are successful, then people adopt it. It’s just a steady progression.”
Fracking in the Marcellus Shale became controversial because it sends millions of gallons of water laced with chemicals into each well to crack the rock and push sand into the cracks, holding them open to release gas.
Drillers add chemicals to cut friction and stop bacterial or calcium buildup in bore holes. The mix has included hydrochloric acid and diesel fuel.
Vidic has suggested using acid mine water in fracking as a way to get rid of a potential pollutant since most frack water gets locked underground.
Kittanning-based MDS Energy Ltd. moved to nitrogen fracking when Pennsylvania banned the dumping of drilling wastewater in rivers and streams. Its mix of 65 percent nitrogen and 35 percent water cuts water usage by about 80 percent to 163,000 gallons per well, said company spokesman Michael S. Knapp.
Chesapeake Energy Corp., the second-largest U.S. natural-gas producer, announced recently that it is testing frack fluids with only benign additives. The company states on its website that it began eliminating unneeded chemicals three years ago.
That’s when several national trade groups pushed for more environmentally acceptable fluids, said Jim Venditto, vice president of technical services for Trican Well Service Ltd. in Calgary, Canada.
Canadian and Middle Eastern drillers are experimenting with seawater, Venditto said. Drillers in some parts of the Appalachian basin, such as West Virginia, have used pressurized gas along with water.
Other companies predict waterless fracking in the future. GASFRAC Energy Services Inc. touts its use of a propane gel, and Chimera Energy Corp. claims it can use helium to frack.
“We’d all like to use a nonwater-based fluid. That’s the Holy Grail,” Venditto said. “But right now I’d say the biggest push in the industry is to utilize as much of the recycled [frack] water as you can ... and look for the new and novel technology for waterless fracks in the future.”
Waterless fracking would reduce potential for spills, transportation costs and water usage in areas where water is scarce.
Yet it comes with risks, too. Pressurized gas can be a fire or explosion hazard. It can be expensive to acquire and process from the produced gas, especially from wells that produce pure methane, experts said.