摘要:Formation water is extracted throughout the life of the fields ofhydrocarbons together with oil and/or gas. Oil dehydration costs, as well asthose of production water reinjection represent significant component in totalcosts at mature oil and gas fields. The optimization of the aforesaid costs,from the point of technology and economics, can affect both profitability(cost-effectiveness) and development of the oil field in the future.Methodology of calculation of unit cost will be elaborated in this paper fortreatment of produced water (dehydration) and production water reinjection. Themethodology of calculation of unit cost for disposal of produced water will beapplied at production of mature oil and gas field. Unit cost for disposal ofproduced water for the period 2009 – 2014 will be calculated in the selectedexample. Making of this particular model of calculation of disposal costs ofproduced water is crucial for economy analyses of hydrocarbons exploitationfrom mature fields.