The book presents modern concepts of electrolyte solutions that are crucial in the process of application of chemicals production, transportation and treatment. The different compositions elektrosoderzhaschie, held their systematization, analysis and synthesis of all the basic properties of electrolyte solutions, methods of calculation, management and settlement, involving extensive theoretical and experimental literature data. Focuses on the influence of thermobaric factor corresponding to the real reservoir and well conditions. Theoretical calculations are accompanied by case studies that allow them to bring to the solution of practical problems. Taken together, the material described leads to a deeper understand the diversity of properties, both of the electrolytes and their solutions that are critical to oil field chemistry.