Chloride Concentration Gradients in Tank-Stored Hydraulic Fracturing Fluids Following Flowback

TitleChloride Concentration Gradients in Tank-Stored Hydraulic Fracturing Fluids Following Flowback
Publication TypeGovernment Report
Year of Publication2011
AuthorsEdwards PJ, Tracy LL, Wilson WK
PublisherU.S. FOREST SERVICE
Place PublishedNEWTOWN SQUARE PA
Call Number10
KeywordsChloride, Energy, Flowback, Fluids, Industry
Notes
A natural gas well in West Virginia was hydraulically fractured and the flowback was 
recovered and stored in an 18-foot-deep tank. Both in situ field test kit and laboratory 
measurements of electrical conductivity and chloride concentrations increased substantially 
with depth, although the laboratory measurements showed a greater increase. The field 
test kit also underestimated chloride concentrations in prepared standards when they 
exceeded 8,000 mg L-1, indicating that laboratory analyses or other more accurate methods 
of detection should be used to determine chloride concentrations in flowback when they may 
be approaching West Virginia regulatory levels (12,500 mg L-1) that disallow disposal by land 
application. The gradation of chloride with depth also has implications for procedures used 
to collect flowback samples from reserve pits or tanks before disposal to ensure the resulting 
composite chloride concentration is representative of the total volume.
URLhttp://www.nrs.fs.fed.us/pubs/rp/rp_nrs14.pdf