More advanced recycling rather than disposal of water produced by hydraulic fracturing could calm fears of accidental spillage and save millions of gallons of fresh water a year, according to Rice University scientists.
The study, which appears in the Royal Society of Chemistry journal Environmental Science: Processes and Impacts, includes a detailed analysis of produced water of three gas reservoirs and suggests environmentally friendly remedies are needed to treat and reuse it.
The amount of water used by Texas drillers for fracking may only be 1.5 percent of that used by farming and municipalities, but it still amounts to as much as 5.6 million gallons a year for the Texas portion of the Haynesville formation and 2.8 million gallons for Eagle Ford.
Rice chemist Andrew Barron, who led the study, says shale gas wells produce most of their water within the first few weeks of production. After that, a few barrels a day are commonly produced.
The project began with chemical analysis of fracking fluids pumped through gas-producing shale formations in Texas, Pennsylvania and New Mexico. Barron and the study’s lead author, Rice alumnus Samuel Maguire-Boyle, found that shale oil and gas-produced water does not contain significant amounts of the polyaromatic hydrocarbons that could pose health hazards, but minute amounts of other chemical compounds led them to believe the industry would be wise to focus its efforts on developing nonchemical treatments for fracking and produced water.
Fracking companies may encounter intense competition for water, as 38 percent of the world’s shale resources are either under extremely high water stress or facing arid conditions, according to a report published earlier this month by the World Resources Institute.