Improving mining development modelling based on the thermal methods

Abstract

Introduction. The problem of oil recovery growth and oil reserves management improvement in active oil fields is growing annually. It is possible to increase oil recovery and improve oil reserves management by introducing the thermal methods of oil production. This method was applied at the Yarega oil field. The thermal mining development technology is currently being implemented at the Yarega territory on an industrial scale. Lyael territory is developed by SAGD technology. Heat capacity and thermal conductivity are crucial characteristics of rocks. Reference books and databases lack reliable data on sedimentary rocks thermal properties. The traditional experimental base of thermal petrophysics cannot provide representative information on the thermal properties of rocks, considering rock heterogeneity and anisotropy, various fluid saturation, and pressure and temperature fluctuations. Results. According to special petrophysical studies of the Yarega highly viscous oil field core, ambiguity has been revealed in the thermal properties of rocks, including anisotropy, heat capacity and thermal conductivity. When applying laboratory results in modeling, divergence in oil production and cumulative steam oil ratio can reach 60%. Main ambiguity arising in the course of thermal mine development modeling has been identified. The ambiguity is associated with the account of production for a well, a large number of underground wells, and low reservoir pressure (lower than atmospheric pressure). These problems are successfully solved by specialists of the Yarega field, who maintain highly viscous oil development. At low reservoir pressures, the simulator encounters errors on low pressure values during well operation. Conclusions. At the Yarega field, permanent geological and technological model is currently actively being implemented. It is aimed at solving technological problems of ambiguity in the development of highly viscous oil by thermal methods using advanced software.