Nonionic Surfactant Analysis from Marcellus Shale Flowback Waters Using LC-High Resolution Accurate Mass Detection

Oral Presentation

Prepared by R. Jack
Thermo Fisher Scientific, 1214 Oakmead Parkway, Sunnyvale, CA, 94085, United States


Contact Information: [email protected]; 408-481-4227


ABSTRACT

Shale gas exploration has dramatically increased in recent years due to the developments in hydraulic fracturing. Hydraulic fracturing (or fracking) extracts hard-to-reach natural gas and oil from deep underground deposits by drilling a well into bedrock (primarily shale) and then injecting fluid under high-pressure causing cracks to form. These cracks release trapped hydrocarbons that can be captured. Fracking fluid contains approximately 90% water which can be sourced from ground water, surface water, or treated wastewater. The remainder of the fluid includes sand and chemical additives such as friction reducers, anti-bacterial agents, surfactants, and corrosion inhibitors. Sand is used to prop open cracks, facilitating the flow of hydrocarbons. Upon relieving the injection pressure, the fracking fluid’s direction of flow reverses which returns fracking wastewater to the surface. Wastewater produced from hydraulic fracturing (fracking) contains salts (anions and cations), metals, and radioisotopes that have been mobilized from the hydrocarbon-rich shale layer at up to 20 times seawater concentrations. However, few analytical methods exist for the analysis of the myriad organic compounds in hydraulic fracturing flowback waters that withstand the robustness requirements from such high TDS samples. In addition, hydraulic fracturing chemicals vary widely due to operator experience, costs, subsurface requirements and trades secrets. Often the concentrations of the exact chemical makeup are unknown upon injection. Here we report a workflow that removes high TDS and positively identifies previously uncharacterized nonionic surfactant components of hydraulic fracturing flowback waters by High Resolution Accurate Mass (HRAM) Detection using Orbitrap® technology.