Experience in Assessing the Toxicity of Formation (Produced) Water of the LUKOIL-Ukhtaneftegaz RPC for the Environment

The chemical composition and toxicity for living organisms-aquatic organisms of reservoir (waste) and surface (for injection into reservoir) waters of production facilities of the LUKOIL-Ukhtaneftegaz RPC were studied. It has been established that highly mineralized formation waters have acute toxicity for daphnia, green unicellular algae and fish fry, which is eliminated by diluting the samples 2–100 times. Indicators of the Lethal Dilution Ratio of LDR50 and lethal concentrations of LC50 of the studied water samples were calculated for test organisms, which ranged from 10,780 to 27,910 mg/l, averaging 21,140 mg/l. It was concluded that the studied samples of formation water, which differ significantly (by 3–4 orders of magnitude) in a positive direction from the standard LC50 concentration of 10 mg/l, cannot be classified as substances that pose a hazard to the natural environment.

1. Jimenes S., Mico M.M., Arnrldes M.,Medina F., Contreras S. State of the art of produced water treatment. Chemosphere. 2018. Vol. 192. P.186—208.

2. Mohammad A. Al-Ghauti, Mariam A.-Al Kaabi, Mohammad Y.Ashfag, Dana Adel Dana. Produced water characteristics, treatment and reuse. A review. Journal of Water Process Engineering. 2019. Vol. 28. P.222—239.

3. Овсянникова И.В., Пряничникова В.В., Пашкина К.В., Лебедь И.В., Сурина А.Г., Гизетдинов А.Н. Оценка фитотоксичности попутных нефтяных вод. Нефтегазовое дело. 2018. Т. 16. № 4. С. 141—145.

4. Lei Hu, Wenbin Jiang, Xuesong Xu, Huiyao Wang, Kenneth C. Carroll, Pei Xu, Yanyan Zhang. Toxicological characterization of produced water from the Permian Basin. Science of The Total Environment. 2022. Vol. 815. P. 15294.

5. Терехова В.А. Биотестирование почв: подходы и проблемы. Почвоведение. 2011. № 2. С. 190—198.

6. Гончарова Е.Н, Рыбина С.Ю. Химический состав пластовой воды. Chemical Bulletin. 2020. Т. 3. № 2. С. 5—14.

7. Parsy A., Guyoneaud R., Lot M.C., Baldoni-Andrey P., Pйriй F., Sambusiti C. Impact of Salinities, Metals and Organic Compounds found in saline oil & gas produced Water on Microalgae and Cyanobacteria. Ecotoxicology and Environmental Safety. 2022. Vol. 234. P.113351.

8. Boyd A., Myers S.P, Luu I., Freitag K., Blewett T.A., Snihur K., Alessi D.S. A Common well pad does not imply Common toxicity: assessing the acute and chronic toxicity of Flowback and produced waters from four Montney formation wells on the Same well pad to the freshwater invertebrate Daphnia magna. The Science of the total Environment. 2022 Vol. 807. P. 150986.