Experience of mechanical modeling application for multiphase flow parameters in the wellbore of the Achimov deposits of the Urengoy oil and gas condensate field for the purpose of pressure gradient extended forecast
Experience of mechanical modeling application for multiphase flow parameters in the wellbore of the Achimov deposits of the Urengoy oil and gas condensate field for the purpose of pressure gradient extended forecast Given article presents the materials related to the issues of wells' stable performance under low-permeability reservoirs and significant influence of formation fluid phase transformations on the extraction processes. One of the key tasks in this process is calculation of the wells performance process mode, in particular - hydrodynamic calculation of multiphase flow parameters in the wellbores of various designs for specified wellhead parameters and a certain composition of fluid extracted. This article analysis of the multiphase flows mathematical modeling common methods allows for two main approaches selection - empirical correlations and mechanistic models. The article also describes experience of mechanistic approach for the multiphase flow motion modeling and pressure losses determination along the wellbore. This explicitly takes into account the influence of the wellbore spatial position and the fluid phase in the well design elements. This allows for taking into account of the phases properties determination, flow heterogeneity, its structure, flow non-isothermality and, consequently, the pressure gradient change along the wellbore. Calculated values are compared with the actual values measured with the downhole sensors. Evidencing from three Achimov wells a higher accuracy of bottom hole pressure calculations is shown for Anzari mechanistic model compared with Adamov's formula. One of the notable examples is the experience of calculation algorithm development for bottom hole pressure in the wells, operating Valanginian stage of the Urengoy oil and gas condensate field. Based on the field hydrodynamic researches of the well bed, the model of gas-condensate and water-methanol mixture flow was developed, and significant progress for actual gas content and bottom hole pressure values forecast were achieved (calculation error was less than 1%).