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coupled-axial-torsional-vibrations
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Modeling and Control of Vibrations in Horizontal Drill String with Coupled Axial and Torsional Vibrations
, M.Sc. Thesis Sharif University of Technology ; Moradi, Hamed (Supervisor) ; Vossoughi, Gholamreza (Supervisor)
Abstract
Oil and natural gas today are one of the most important sources of human energy supply, so that crude oil Percentage and natural gas provide 25% of the world's energy. Until now, vertical drilling methods have been used to extract oil and gas. In recent years, due to vertical drilling constraints, for extraction and access to places that can not be achieved by vertical drilling, Horizontal drilling has been increased. In horizontal drilling, a variety of vibrations including longitudinal, torsional, and lateral take place. These vibrations, if not controlled, can damage the equipment and the drilling field, as well as reduce the efficiency of the drilling process and increase the process...
Prediction-based Control for Mitigation of Axial-torsional Vibrations In a Distributed Drill-String System in the Presence of Parametric Uncertainties
, M.Sc. Thesis Sharif University of Technology ; Vossoughi, Gholamreza (Supervisor) ; Zohoor, Hassan (Supervisor)
Abstract
Drill strings are subjected to complex coupled dynamics. Therefore, accurate dynamic modeling, which can represent the physical behavior of real drill strings, is of great importance for system analysis and control. The most widely used dynamic models for such systems are the lumped element models which neglect the system distributed feature. In this thesis, an infinite-dimensional model for the vibrational dynamics of the drill-string, called neutral-type time delay model, is modified to investigate the coupled axial-torsional vibrations in drill strings. This model is derived directly from the distributed parameter model by employing the d’Alembert method. Coupling of axial and torsional...
Analysis and Design of an Observer and Robust Controller to Reduce Undesired Coupled Axial-Torsional Vibrations in A Horizontal Drill String
, M.Sc. Thesis Sharif University of Technology ; Moradi, Hamed (Supervisor)
Abstract
Nowadays, horizontal drill string is a powerful tool for drilling in the oil and gas industry and an efficient method for constructing underground tunnels in cities. Despite its many uses, this method is exclusive to limited countries and is considered among the most advanced methods for drilling. One of the most important problems in the field of horizontal drilling is the existence of destructive axial, torsional and lateral vibrations. If these vibrations are not controlled, they can cause irreparable damage to the plant and drilling well. Among the introduced vibrations, axial and torsional vibrations have a very dominant effect on the drilling process, so the purpose of this research is...
Coupling analysis and control of axial and torsional vibrations in a horizontal drill string
, Article Journal of Petroleum Science and Engineering ; Volume 195 , 2020 ; Moradi, H ; Vossoughi, G ; Sharif University of Technology
Elsevier B.V
2020
Abstract
Vertical drilling methods have been often used for oil and gas extraction so far. In some places, for further extraction and access to the locations that cannot be obtained by the vertical drilling (due to its restrictions); horizontal drilling has become more popular. In horizontal drilling, a variety of longitudinal, torsional and lateral vibrations occur. These vibrations, if left uncontrolled, can damage the drilling rig and equipment, as well as reduce the efficiency of the drilling process and increase the processing time. The purpose of this research is to obtain the coupled axial and torsional vibration equations by analysing the vibrational modes in the horizontal section of the...
Modification of the infinite-dimensional neutral-type time-Delay dynamic model for the coupled axial⇓torsional vibrations in drill strings with a drag bit
, Article Journal of Computational and Nonlinear Dynamics ; Volume 15, Issue 8 , 2020 ; Vossoughi, G ; Zohoor, H ; Azadi Yazdi, E ; Sharif University of Technology
American Society of Mechanical Engineers (ASME)
2020
Abstract
Drill strings are subjected to complex coupled dynamics. Therefore, accurate dynamic modeling, which can represent the physical behavior of real drill strings, is of great importance for system analysis and control. The most widely used dynamic models for such systems are the lumped element models, which neglect the system distributed feature. In this paper, a dynamic model called neutral-type time delay model is modified to investigate the coupled axial–torsional vibrations in drill strings. This model is derived directly from the distributed parameter model by employing the d’Alembert method. Coupling of axial and torsional vibration modes occurs in the bit–rock interface. For the first...