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Chloride concentration gradients in tank-stored hydraulic fracturing fluids following flowback
Res. Pap. NRS-14. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 14 p.
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.
Edwards, Pamela J.; Tracy, Linda L.; Wilson, William K. 2011. Chloride concentration gradients in tank-stored hydraulic fracturing fluids following flowback. Res. Pap. NRS-14. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 14 p.
Last updated on: August 12, 2011