Fully coupled vibrations of actively controlled drillstrings

Christoforou, Andreas P.; Yiğit, Ahmet S.

doi:10.1016/s0022-460x(03)00359-6

Cited by 147 publications

(75 citation statements)

References 16 publications

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“…Some authors have proposed different models to represent the dynamics of a drill-string as, for instance, [13][14][15][16][17][18][19][20][21]. The model used in this paper takes into account the drive force at the top (as a constant rotational speed), the support force at the top (known as weight-on-hook) and the bit-rock interaction.…”

Section: Introductionmentioning

confidence: 99%

Robust optimization of the rate of penetration of a drill-string using a stochastic nonlinear dynamical model

2010

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This work proposes a strategy for the robust optimization of the nonlinear dynamics of a drill-string, which is a structure that rotates and digs into the rock to search for oil. The nonparametric probabilistic approach is employed to model the uncertainties of the structure as well as the uncertainties of the bit-rock interaction model. This paper is particularly concerned with the robust optimization of the rate of penetration of the column, i.e., we aim to maximize the mathematical expectation of the mean rate of penetration, respecting the integrity of the system. The variables of the optimization problem are the rotational speed at the top and the initial reaction force at the bit; they are considered deterministic. The goal is to find the set of variables that maximizes the expected mean rate of penetration, respecting, vibration limits, stress limit and fatigue limit of the dynamical system.

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Section: Introductionmentioning

confidence: 99%

Robust optimization of the rate of penetration of a drill-string using a stochastic nonlinear dynamical model

2010

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“…The type and the complexity of the model to be used are closely related to the aim pursued (modelling, simulation, model for control, etc). However, lumped parameters models have been shown to be valid enough to properly describe the stick-slip oscillation phenomena and easy enough to make the study not too complex [10].…”

Section: System Modellingmentioning

confidence: 99%

“…In this work, the structure of the velocity controller is inspired by the one presented in [10], as shown by:…”

Section: A Rotary Table Velocity Control Loopmentioning

confidence: 99%

D-OSKIL: A New Mechanism for Controlling Stick-Slip Oscillations in Oil Well Drillstrings

Canudas‐de‐Wit

Rubio

Corchero

2008

IEEE Trans. Contr. Syst. Technol.

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“…On the other hand detailed models with many degrees of freedom may be more realistic, but are computationally expensive and do not necessarily provide clear insight into the effect of parameters on system behaviour (e.g. [6][7][8][9]). The literature also reveals a variety of approaches taken to modelling interfaces between the drillstring and the borehole, with particular focus on the cutting interface at the drillbit.…”

Section: Introductionmentioning

confidence: 99%

An efficient model of drillstring dynamics

Butlin

Langley

2015

Journal of Sound and Vibration

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a b s t r a c tHigh amplitude vibration regimes can cause significant damage to oilwell drillstrings: torsional stick-slip oscillation, forward whirl and backward whirl are each associated with different kinds of damage. There is a need for models of drillstring dynamics that can predict this variety of phenomena that are: efficient enough to carry out parametric studies; simple enough to provide insight into the underlying physics, and which retain sufficient detail to correlate to real drillstrings. The modelling strategy presented in this paper attempts to balance these requirements. It includes the dynamics of the full length of the drillstring over a wide bandwidth but assumes that the main nonlinear effects are due to spatially localised regions of strong nonlinearity, for example at the drillbit cutting interface and at stabilisers where the borehole wall clearance is smallest. The equations of motion can be formed in terms of this reduced set of degrees of freedom, coupled to the nonlinear contact laws and solved by time-domain integration. Two implementations of this approach are presented, using (1) digital filters and (2) a finite element model to describe the linear dynamics. Choosing a sampling period that is less than the group delay between nonlinear degrees of freedom results in a decoupled set of equations that can be solved very efficiently. Several cases are presented which demonstrate a variety of phenomena, including stick-slip oscillation; forward whirl and backward whirl. Parametric studies are shown which reveal the conditions which lead to high amplitude vibration regimes, and an analytic regime boundary is derived for torsional stick-slip oscillation. The digital filter and finite element models are shown to be in good agreement and are similarly computationally efficient. The digital filter approach has the advantage of more intuitive interpretation, while the finite element model is more readily implemented using existing software packages.

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Fully coupled vibrations of actively controlled drillstrings

Cited by 147 publications

References 16 publications

Robust optimization of the rate of penetration of a drill-string using a stochastic nonlinear dynamical model

Robust optimization of the rate of penetration of a drill-string using a stochastic nonlinear dynamical model

D-OSKIL: A New Mechanism for Controlling Stick-Slip Oscillations in Oil Well Drillstrings

An efficient model of drillstring dynamics

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