Release:2018, Vol. 4. №3
About the authors:Igor E. Mashchitskiy, Postgraduate Student, University of Tyumen; firstname.lastname@example.org
This article describes a new and unique way to calculate the characteristic curves of phase behavior for oil-type systems on pressure-temperature (thermobaric) plane. The authors touch upon such aspects of phase behavior modeling as method of determining the equilibrium vapor-liquid ratio in specific thermobaric conditions, formal model of system under study structure, determination scheme of phase behavior regions and calculation algorithm of isolines of gas/liquid mass-content. The basic mathematical apparatus of the proposed method is the Peng-Robinson equation-of-state, in this connection the problems of component-fractial composition formation for hydrocarbon mixtures and the selection of relevant formulas for the physical and chemical parameters of fractions are considered. Target curves represented as the discrete functions, each one describe a fixed separation relation in the two-phase region of the system, and their calculation algorithm — as geometric rule set on thermobaric plane consisting computation logic. The key feature of proposed method is the accounting of retrograde evaporation/condensation phenomena for each isoline without reference to any other characteristic curves, and also high scalability of the final result. The calculation algorithms listed in the article were implemented as .NET-software using parallelization technologies. Software-based phase behavior model is graphically illustrated and verified by contact condensation experimental data gathered on reservoir sample of real gas-condensate sample. Since the extraction, processing and transportation of hydrocarbons is unthinkable without a reliable phase states theory, this research can be applied in the most diverse areas of the oil and gas industry.