Halliburton Co. and Schlumberger Ltd., trying to forestall a regulatory crackdown that would cut natural-gas drilling, are developing ways to eliminate the need for chemicals that may taint water supplies near wells.
At risk is hydraulic fracturing, or fracking, a process that unlocked gas deposits in shale formations and drove gains in U.S. production of the fuel. Proposed regulations might slow drilling and add $3 billion a year in costs, a government study found. As one solution, energy companies are researching ways to kill bacteria in fracturing fluids without using harmful chemicals called biocides.
“The most dangerous part in the shale frack is the biocide,” said Steve Mueller, chief executive officer at Southwestern Energy Co., the biggest producer in the Fayetteville Shale of Arkansas. “That’s the number-one thing the industry is trying to find a way around.”
U.S. House and Senate bills introduced in 2009 would force producers to get federal permits for each well. That and other proposed environmental measures would cut drilling by as much as half and add compliance costs of as much as $75 billion over 25 years, according to a study done for the U.S. Energy Department.
Biocides are employed because the watery fluids used to fracture rocks heat up when they’re pumped into the ground at high speed, causing bacteria and mold to multiply, Mueller said. The bacteria grow, inhibiting the flow of gas.
“You basically get a black slime in your lines,” he said in an interview. “It just becomes a black ooze of this bacteria that grew very quickly.”
Halliburton and Schlumberger, the world’s largest oilfield contractors, are among companies seeking biocide substitutes. Houston-based Halliburton said March 9 that it’s testing a process using ultraviolet light to kill bacteria in fracking fluid.
About 80 percent of gas wells drilled in North America are stimulated or fractured in some way, Tim Probert, corporate- development chief at Halliburton, said in a telephone interview.
“It’s incumbent on the industry to continue to develop tools and technologies that are compatible with minimizing the environmental impact of the stimulation process,” Probert said.
Houston-based ConocoPhillips, the third-largest oil company, said March 9 that the world has centuries of gas supplies, largely in unconventional deposits such as shale.
Schlumberger, based in Houston and Paris, spoke with Southwestern about testing a biocide that would last only a few hours before becoming nontoxic, Mueller said. “We have not tested it,” he said. “We only know they’re working on it.”
Schlumberger spokeswoman Mary Jo Caliandro, who confirmed the company is testing new technology, declined to comment on any advance before it’s “commercial.”
Houston-based Southwestern has tested an ultrasonic technique that moves water faster than the speed of sound through a cone-shaped vortex to kill bacteria before the fluid is sent down the well, Mueller said.
“At high speeds, something will happen called cavitation,” he said. “You’re basically smacking the bugs upside the head and killing them.”
Chemicals, including biocides such as chlorine, make up less than 1 percent of fracking fluids. The rest is water and sand. Companies haven’t identified the chemicals they use, citing competitive reasons. Advocacy organizations such as the Environmental Working Group in Washington have called for lawmakers to require energy companies to disclose the chemicals.
“I think the industry’s going to have to be more transparent,” Steven Farris, CEO at Houston-based Apache Corp., the biggest independent U.S. oil producer by market value, said March 22 at the Howard Weil Energy Conference in New Orleans. “‘You can’t say, ‘Trust me.’”
Gas producers are realizing they have to find ways to clean and recycle the water used in hydraulic fracturing, said George P. Mitchell, the Houston billionaire who pioneered development of shale gas in the Barnett formation of North Texas.
“I think a lot of action is going on to get that done,” Mitchell said in a telephone interview. “It’s not an insurmountable task.”
Environmental issues generally begin to be addressed after companies realize there will be a financial cost if they don’t act, said Geoff Kieburtz, an analyst at Weeden & Co. in Greenwich, Connecticut. “The oil industry is as good as any at recognizing those things change over time,” he said.
House and Senate bills introduced in June would force producers to wait for the U.S. Environmental Protection Agency to develop a permitting process. They’d then have to get approval from the agency for each well. The EPA said March 18 it will spend $1.9 million to study risks associated with fracking.
Environmental concerns over gas production go beyond biocides. Two of 94 monitoring sites at the Barnett Shale, the most productive U.S. shale formation, had elevated levels of the carcinogen benzene in the air, the Texas Commission on Environmental Quality said in January.
“Now, when they have the possibility that something might stop the fracturing and stop the development of the shale, that’s what you have to worry about,” said Mitchell.