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Registration Number

0824U000243, PhD dissertation

Title

Mathematical Modeling and Optimal Control of Mud Motor Drilling Process

Author

Dmytro Kropyvnytskyi,

popup.head Mikhailo Horbiychuk
popup.opponent Mykhailo Alekseyev
popup.opponent Olga Khymko
popup.review Mykhailo V. Shavranskij
popup.review Yaroslav Zaiachuk

Status

Доктор філософії, 151, Автоматизація та приладобудування. Автоматизація та комп’ютерно-інтегровані технології

Date

22-02-2023

Description

The dissertation work provides a theoretical generalization and solution to the current scientific and practical problem of optimal control in the drilling process of oil and gas wells using mud motors under conditions of uncertainty regarding the criterion of the cost per meter of penetration, taking into account the rational utilization of the drilling tool life, which allowed to synthes the corresponding optimal control system. The introduction provides an exposition of the current state of the scientific problem, its significance, and justifies the relevance of the dissertation research topic. The introduction formulates the purpose and defines the main tasks of the chosen research direction. The first chapter describes, the technological process of well drilling, considering it as an object of automation characterized by a large number of operational parameters that, to some extent, determine its efficiency. A mathematical model of the well-drilling process with mud motors is proposed In the second chapter, which includes an analytical relationship that establishes the connection between the angular velocity of the asynchronous motor and the pressure of the drilling fluid. A method for optimal control of the mechanical drilling process with a mud motor drive is developed In third chapter. This method combines rational tool life utilization and the selection of optimal control actions – axial load on the bit and pressure of the drilling fluid – based on the criterion of minimizing the cost per meter of penetration, while considering known constraints on control actions. Two-level scheme of optimal control for the well-drilling process has been developed In the fourth chapter. In this section, the problem of the second level of control is solved, which involves maintaining optimal control values determined at the first level of the system. Keywords: drilling process, well, mud motor, pressure, axial load, optimization, automation, control system, genetic algorithms, mathematical models, modeling, fuzzy variables, approximation, software