Aspects of brane world-volume dynamics in string theory [PDF]
, 2012 PhDThis thesis investigates the non-abelian dynamics of D-Brane systems in String Theory, specifically focussing on the fate of the open string Tachyon.
Tallarita, Gianni
core +4 more sources
Sensing and computational frameworks for improving drill-string dynamics estimation [PDF]
, 2021 International audienceIn this paper, we consider the axial motion of a directional multi-sectional drill-string. The drillstring dynamics are represented by a distributed dynamical model (wave equations) coupled with an ordinary differential equation at ...
Auriol, Jean +2 more
core +1 more source
An impedance approach to reduce the contact-instability whilst drilling with active heave compensation [PDF]
, 2012 The bit-bounce, or contact-instability, phenomenon which occurs in the drill string suspended from a floating vessel with an active drill string compensator to maintain a steady weight on the drill bit is investigated.
Hatleskog, Jan, Dunnigan, Mathew Walter
core +1 more source
Prediction-Based Control for Mitigation of Axial-Torsional Vibrations in a Distributed Drill-String System [PDF]
, 2022 This article proposes a control strategy to stabilize the axial-torsional dynamics of a distributed drill-string system. An infinite-dimensional model for the vibrational dynamics of the drill string is used as a basis for controller design.
Vossoughi, Gholamreza +3 more
core +2 more sources
Non-Linear Dynamic Analysis of Drill String System with Fluid-Structure Interaction
Applied Sciences, 2021 In this research, the non-linear dynamics of the drill string system model, considering the influence of fluid—structure coupling and the effect of support stiffness, are investigated. Using Galerkin’s method, the equation of motion is discretized into a
Rongpeng Wang +3 more
doaj +1 more source
Applied Sciences, 2021 In downhole drilling systems, self-excited torsional vibrations caused by the bit-rock interactions can affect the drilling process and lead to the premature failure of components.
Vincent Kulke +3 more
doaj +1 more source
Modelling of drill string nonlinear dynamics with a drilling fluid flow
Вестник КазНУ. Серия математика, механика, информатика, 2018 In this work the development of mathematical models of drill string dynamics under the influence of internal drilling fluid flow, which is of great importance for ensuring fast, cost-effective and safe process of oil and gas well drilling, is conducted.
Askar K. Kudaibergenov, L. A. Khajiyeva
doaj +1 more source
Nonlinear Model and Qualitative Analysis for Coupled Axial/Torsional Vibrations of Drill String
Shock and Vibration, 2016 A nonlinear dynamics model and qualitative analysis are presented to study the key effective factors for coupled axial/torsional vibrations of a drill string, which is described as a simplified, equivalent, flexible shell under axial rotation.
Fushen Ren +4 more
doaj +1 more source
Effect Of Drill String Rotation On The Dynamic Response Of Drilling Risers [PDF]
, 2015 The effect of the rotation of a drill string on the response of a drilling riser has been studied. A governing equation for the flexural response that incorporates the effect of the drill string rotation is developed from first principles, and the ...
A. Big-Alabo +5 more
core +1 more source
Analysis on Casing Wear Induced by Drill String Whirling during Workover Drill Grinding
Shiyou jixie, 2021 When the drill string rotates in the wellbore, it will whirl, collide with and rub against casing inwall, resulting in casing wear and reducing wellbore safety.
Cao Yinping +3 more
doaj