ИСПОЛЬЗОВАНИЕ МЕТОДОВ ТЕОРИИ АВТОМАТИЧЕСКОГО УПРАВЛЕНИЯ ДЛЯ ПРЕДСТАВЛЕНИЯ МЕХАНИЗИРОВАННОЙ НЕФТЕДОБЫВАЮЩЕЙ СКВАЖИНЫ КАК ОБЪЕКТА УПРАВЛЕНИЯ

Abstract

Background The process of the oil production is characterized by the combination of a number of physical quantities, referred to as process indicators. The reliable interpretation of the process requires that for some of these variables certain conditions must be set, in particular: - maintaining a certain value of the dynamic level in the well annulus during well startup phase; - holding operating temperature conditions of submersible electric motor within the specified limits at pump startup; - switch-on and switch-off of the electric centrifugal pump (ESP) at certain time intervals during cyclic pumping of oil to ensure maximum fluid lift with minimum energy consumption, etc. Aims and objectives To maintain or change, as necessary, the conditions listed above, the need for control arises, which entails the necessity to consider artificial lift oil wells as an object of control. The well state is determined by a number of variables that characterize the impact on the object of both the external environment and the control means. The «submersible electric motor - ESP» system, which controls the object by changing the pump head, is considered as control means. The object implies the system consisting of the bottom-hole zone, the annular space and the tubing. Impacts on the object that do not depend on the control system are called disturbances, and in particular cases they are represented as a possible change of the gas pressure in the well annulus. Results A dynamic mathematic model of operation of oil pumping well as an object of control has been developed. The model is represented in the form of differential equations and transfer functions that ensure effective application of the methods of automatic control theory in solving problems of synthesis and analysis of control algorithms and evaluating stability and controllability of processes in the oil producing well.