Modelling and Optimal Control of Natural Bitumen Deposits Development

摘要

The development of super-heavy oil and bitumen fields using steam-gravity drainage technology (SAGD) involves the use of two horizontal wells located one above the other. The upper well is used to inject steam and create a high-temperature steam chamber in the formation where the vapor condenses and, together with the heated oil, flows down to the lower pipe of the production well. The complexity of monitoring the parameters of the steam chamber (pressure and temperature along the well) makes it difficult to control the production process; the control parameters are the temperature of the supplied steam, the rate of pumping out the water-oil mixture, etc. For decision-making, it is necessary to have an idea of evolution of the steam chamber, the amount of oil inflow into the producing well, the reserves of raw materials that can be extracted by this method, etc. On the same basis, the problem of rational distribution of wells on the surface can be solved. For this problem, the control parameters at the design stage are the characteristics of the geometric distribution of the wells. The paper presents a mathematical model of SAGD, which takes into account the three-phase nature of the process and its nonstationarity.