Organic compounds in produced waters from shale gas wells

Photo Credit: Rice University

The severe drought in California, water-intensive drilling programs needed to increase oil and gas production from shale plays and focus on the energy-water nexus are motivating companies to reduce their water requirements and re-use water needed to hydraulically fracture wells. A new Rice University study conducted detailed analysis into produced water from 3 major US shale gas reservoirs – the Marcellus, Eagle Ford and Barnett – and concluded that recycling water used in the fracking process instead of disposing it could go a long way toward addressing many of the water-related challenges associated with the controversial well completion technology. “Re-use of produced water for hydraulic fracturing is being encouraged; however, knowledge of the organic impurities is important in determining the method of treatment,” the study’s abstract explains.

Read a 3-part Breaking Energy series on drilling wastewater recycling technology here.

“The project began with chemical analysis of fracking fluids pumped through gas-producing shale formations in Texas, Pennsylvania and New Mexico. [Andrew] 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,” according to a statement.

“Ultimately, it will be necessary to clean produced water for reuse in fracking,” Barron said. “In addition, there is the potential to recover the fraction of hydrocarbon in the produced water.”

The study calls on the industry to identify non-chemical frack water recipes that can avoid the formation of toxic compounds. The authors suggested international producers should perfect environmentally-friendly water treatments before expanding shale resource development operations in the UK and other European countries.

“As the U.K. and other European countries are looking to start hydraulic fracturing, it is important that they adopt best practices at the start, as opposed to evolving over time, as it has occurred here in the United States,” Barron said in a release about the study.