Dissolved Methane Round Robin Study Results- Phase 2

Topics in Shale Gas
Oral Presentation

Prepared by D. Gratson
Environmental Standards, P.O. Box 29432, Santa Fe, New Mexico, 87592, United States


Contact Information: dgratson@envstd.com; 505-660-8521


ABSTRACT

In 2014-2015 the Marcellus Shale Coalition Dissolved Methane Method Workgroup commissioned a round-robin study of dissolved light gas analysis. In this initial phase fourteen commercial and one government laboratory analyzed blind groundwater samples that had been collected at two locations. The study identified significant variation among the results, with dissolved methane values that varied from 7,440 to 34,600 g/L for a single sample location in one example. The study showcased the need for a more robust analytical procedure and the need for additional work to identify the source of the variability. In 2016 the Marcellus Shale Coalition commissioned a second study, again using fifteen laboratories, who analyzed four reference standards that were submitted blind. The results of this second study will be presented starting with study design, reference standard preparation, data analysis, and the conclusion that calibration is the primary source of error. Techniques within the calibration process will be discussed relative to the source of error for analysis of dissolved methane.