Down and up again: Composition of fracturing fluids and flowback
19.03.2015
Water Protection
A systematic evaluation of chemicals used in hydraulic fracturing fluids is necessary for a thorough assessment of the potential environmental impact of these substances. Beyond that, the complex composition of flowback water needs to be scrutinised before a decision on proper treatment and reuse/disposal can be made.
To recall: chemicals which are introduced as part of the fracturing fluids down the borehole at high pressures, interact with the water in the target rock formation and with the target rock itself, and return to the surface as part of the so-called flowback water. Flowback water contains, in addition to the chemicals introduced in fracturing fluids, admixtures of high-saline formation waters, substances released from the rocks, and neo-formed reaction products.
Significant knowledge gaps and challenges still exist today regarding potential environmental releases and regarding the technology for the treatment of flowback water. Recently published studies contribute new data relevant for environmental impact assessment, which will aid informed decision-making on treatment of flowback water. It is acknowledged that companies increasingly disclose chemicals used in hydraulic fracturing. But companies are still asked for more information on proprietary additives and on concentrations of chemicals which are used.
Read a review:
Figuring Out Fracking Wastewater
Arnaud, March 2015, Chemical & Engineering News, Web link
This article summarises current scientific results on hydraulic fracturing wastewater and puts them into context.
References to scientifc articles with web links to full texts or abstracts
Physical, chemical, and biological characteristics of compounds used in hydraulic fracturing
Stringfellow et al., 2014, Journal of Hazardous Materials, 275 37–54, Web link
Chemical constituents and analytical approaches for hydraulic fracturing waters
Ferrer and Thurman, 2015, Trends in Environmental Analytical Chemistry, Vol. 5, Pages 18-25, Web link
Biocides in Hydraulic Fracturing Fluids: A Critical Review of Their Usage, Mobility, Degradation, and Toxicity
Kahrilas et al., 2015, Environmental Science & Technology, 49 (1), pages 16–32, Web link
Characterization of hydraulic fracturing flowback water in Colorado: Implications for water treatment
Lester et al., 2015, Science of The Total Environment, Vol. 512–513, Pages 637–644, Web link
Analysis of Hydraulic Fracturing Flowback and Produced Waters Using Accurate Mass: Identification of Ethoxylated Surfactants
Thurman et al., 2014, Analytical Chemistry, 86 (19), pages 9653–9661, Web link
Organic compounds in produced waters from shale gas wells
Maguire-Boyle and Barron, 2014, Environmental Science, Processes & Impacts, 16, 2237-2248, Press release, article on slideshare
New Tracers Identify Hydraulic Fracturing Fluids and Accidental Releases from Oil and Gas Operations
Warner et al., 2014, Environmental Science & Technology, 48 (21), pages 12552–12560, Web link
