Correlation Analysis and Hydrochemical Facies of Contaminant Ions in Oilfield Produced Water of the Upper Assam Basin

The oil field produced water from the Upper Assam Basin, generated during oil and gas exploration and production, contains high levels of contaminants, including inorganic elements and anions, which pose significant environment and health risks. To address these challenges, we employed the Piper class scatter plot and correlation analysis methods to develop new correlations and gain a deeper understanding of the complex relationships among these contaminants. Our analysis revealed elevated concentrations of Na, Li, Sr, Pb and F exceeding the permissible limits set by India’s Central Pollution Control Board, highlighting their potential environmental and health impacts. In contrast, Cr, Cu, Mo and Ni were absent, reflecting varying geochemical influences. The study also examined the roles of Ca and Mg in water hardness and scaling, as well as the severe environmental risks associated with high levels of Zn and Pb. Notably, the Piper class scatter plot analysis identified calcium bicarbonate Ca(HCO3)2 as the predominant component, providing a clearer view of the water’s chemical composition. Correlation analysis, supported by empirical data, indicated that Na is positively correlated with other inorganic parameters, with a proportionality constant of 2.1 e-5. These findings underscore the need for advanced treatment methods to mitigate excessive contaminants and enhance sustainable management practices. The study highlights the importance of employing sophisticated analytical techniques to improve environmental stewardship and operational efficiency in the oil and gas industry.