Monitor Frac Flowback Waters from Unconventional Gas Applications

Shale gas development relies heavily on hydraulic fracturing, and in recent years the industry has focused on reusing frac flowback to reduce both costs and the environmental impact of operations. The challenge has been to identify technologies and approaches for treating the flowback water for beneficial reuse.

A field trial in upstate New York evaluated water samples from different formations in the Marcellus Shale using a mobile laboratory, which housed a pilot-scale treatment system. The mobile system identified the best treatment options accounting for the organic loading and fouling potential. To best measure these organics, a robust total organic carbon (TOC) analyser was required. Before the release of the InnovOx TOC Analyser, TOC measurements were difficult due to the high salts and complex chemistry of a typical frac sample.

GE’s (USA) InnovOx Laboratory TOC Analyser was used because of its robust Supercritical Water Oxidation (SCWO) technology that can handle tough brine samples. In addition, the InnovOx was easily incorporated into the mobile lab and moved around as needed thanks to its internal air pump. All that was needed was power.

For more than 18 months, several large scale field and laboratory studies of frac wastewaters were conducted using the InnovOx. Although these waters were very high in chlorides, bromides, silica, oils, colour and solids, the SCWO method enabled the InnovOx to generate both accurate and precise results in water samples with chlorides as high as 300,000 mg/L.