Master's Dissertation
DOI
https://doi.org/10.11606/D.18.2011.tde-27072011-184508
Document
Author
Full name
Leopoldo Marques Manzatto
E-mail
Institute/School/College
Knowledge Area
Date of Defense
Published
São Carlos, 2011
Supervisor
Committee
Trindade, Marcelo Areias (President)
Balthazar, Jose Manoel
Nicoletti, Rodrigo

Title in Portuguese
Análise dinâmica de colunas de perfuração de poços de petróleo usando controle linear de velocidade não-colocalizado
Keywords in Portuguese
Controle de vibrações torcionais
Dinâmica de colunas de perfuração
Fenômeno de stick-slip
Perfuração de poços de petróleo
Abstract in Portuguese

Title in English
Dynamics of oilwell drillstrings using non-colocated linear velocity control
Keywords in English
Drillstring dynamics
Oil well drilling
Stick-slip phenomenon
Torcional vibration control
Velocity control
Abstract in English
This paper presents a parametric analysis of the dynamics of oilwell drillstrings with non-collocated proportional-integral velocity control. The drilling operation for oil and gas in deep waters consists of opening wells in rocky ground formation by a drill, whose angular speed is controlled by a rotary table at the surface. The torque applied by the table is transmitted to the drill-bit through the drillstring. Particularly in the deepwater drilling case, the drillstring can be very long and therefore very flexible. The vibrations caused by the great flexibility of drilling columns are mainly responsible for the failures in the drilling process. In particular, the nonlinear phenomenon known as stick-slip and related to the torsional vibration of the drillstring, makes that a control system designed to maintain a constant angular velocity at the table yield large variations at the drill-bit angular velocity. In practice, this phenomenon is amplified by the inherent nonlinearity of the contact between drill bit and rock formation and by the strong non-colocalization between rotary table and drill-bit. The main objective of this work is to perform a parametric analysis of the dynamics of the drilling process, using a two degrees of freedom model in order to represent the rotary table assembly, the drilling column and drill-bit, to identify conditions in which a simple control law, such as a linear proportional-integral velocity control, can provide a stable and satisfactory drilling performance.

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Publishing Date
2011-07-29

WARNING: The material described below relates to works resulting from this thesis or dissertation. The contents of these works are the author's responsibility.
• MANZATTO, L.M., e TRINDADE, M.A. Analysis of stability and performance of an oil well drilling operation subject to stick-slip using non-collocated linear velocity control. In 21st ABCM International Congress of Mechanical Engineering (COBEM), Natal, 2011. Proceedings of the 21st ABCM International Congress of Mechanical Engineering (COBEM)., 2011.

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