Determining Conventional and Unconventional Oil and Gas Well Brines in Natural Samples III: Mass Ratio Analyses Using Both Anions and Cations

Creators

Tetiana Cantlay, Duquesne UniversityFollow
Daniel J. Bain, University of PittsburghFollow
John F. Stolz, Duquesne UniversityFollow

Document Type

Dataset

Description

Identifying the types of contamination and their sources in surface and groundwater is fundamental for effective protection of private and public source waters. Here we employed mass ratio analyses of a variety of anion and cation pairs to characterize flowback, produced water, mine drainage etc. These endmembers were used to evaluate the source contributions of natural surface and ground water samples. A total of 1,177 ground water and surface water samples were analyzed including high-quality source waters and waters suspected of being impacted by drilling and mining activity. We found the following chemical ratios resolved different sources of contamination: Mg/Na vs SO₄/Cl; SO₄/Cl vs Mg/Li; Br/SO₄ vs Ba/Cl; and Br vs Mg/Li. While no single parameter or mass ratio pairing by itself was definitive it was possible to converge on a likely source of contamination using multiple lines of analytical evidence. Further, this process clarified sources in impacted samples where one or more parameters commonly considered diagnostic of specific sources (e.g., Br, Ba), were below detection limits (e.g., too dilute) or not tested for. Ultimately, movement of sample values within the mass ratio space allows tracking of changes in water quality and contamination source dynamics as the water chemistry evolves.

Recommended Citation

Cantlay, T., Bain, D. J., & Stolz, J. F. (2019). Determining Conventional and Unconventional Oil and Gas Well Brines in Natural Samples III: Mass Ratio Analyses Using Both Anions and Cations. Retrieved from https://dsc.duq.edu/biology-data/2

Additional Files

Well water survey study dataset.xlsx (711 kB)