Marcellus Unconventional Gas Extraction Using OES
8:00a.m.PST / 11:00a.m.EST / 16:00GMT
ICP-OES Product Manager,
Thermo Fisher Scientific
Director at The Center for Environmental Research and Education & Professor of Biological Sciences,
The slickwater stimulation of unconventional gas and oil shale creates flowback water with a composition unique to the Marcellus Shale formation. Characteristically, these fluids contain high concentrations of salts (e.g., chloride and bromide) as well as a suite of other elements (e.g., strontium, barium, arsenic, and uranium) that increase in concentration over time. Monitoring these changes requires analysis of multiple sample sets from the same well. In addition, monitoring drinking water wells in areas with shale gas development has resulted in a concomitant need for routine water analysis.
The purpose of our analysis here is to determine whether slickwater stimulation and associated activities (e.g., recycling of produced water in open impoundments) for natural gas extraction from the Marcellus Shale can impact water quality. We will analyze samples of flowback from the initial stage (0–5,000 barrels) to later stages using both Optical Emission Spectroscopy (OES) and Inductively Coupled Plasma–Mass Spectrometry (ICP-MS). We will also analyze well water samples by both OES and ICP-MS and will generate comparable data sets. Although not as sensitive as ICP-MS and requiring a larger volume of sample, OES has several advantages: most samples do not require dilution; OES is not as sensitive to chloride interference; and OES requires less sample preparation and run time. Therefore, OES appears to offer an alternative to ICP-MS for elemental analysis of flowback and produced water, and also for monitoring well water quality.
- The analytical techniques used for anions and metals in waters affected by hydraulic fracturing (fracking)
- What validated methods are appropriate for accurate analysis
- The importance of baseline monitoring to assess potential impacts of slickwater stimulation of shale