When artificial lift well operating with a high gas saturation of oil, a flowing mode may occurs through the annular space, due to the inability of the submersible pump to ensure the pumping of the entire produced volume of the gas-liquid mixture. To analyze and optimize the operation of these wells mathematical model and a software module are created. The mathematical model is a system of one-dimensional differential equations. Modeling of the system is divided into three components: the section from the bottomhole to the reception of submersible equipment, the tube and the annulus. The liquid division factor is calculated, on which the volume of liquid entering the annulus depends. The coefficient is calculated by solving the optimization problem for each downhole pressure under consideration. The developed mathematical model is implemented as a software module that allows to get a complete picture of the processes occurring in the well. The module allows to analyze the presence of flowing through the annulus, as well as the distribution of flows and pressures in the tube and annular space of the well for the initial data of interest. Based on the developed model, a functional for optimizing the operating modes of such wells is implemented, which allows determining the optimal control actions on the well to achieve the selected optimization criterion. A comparative analysis of the calculation results using the developed model and commercial software for modeling unsteady multiphase flows, as well as with data from bench studies and field operation, was carried out.
The developed model does not require an additional initial data beyond the standard set of information maintained by field operator. This allows automating the processes of model creation and adaptation.
References
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