Modelling and dynamic analysis of an anti-stall tool in a drilling system including spatial friction

Abstract

This paper investigates the effects of a down-hole anti-stall tool (AST) in deviated wells on the drilling performance of a rotary drilling system. Deviated wells typically induce frictional contact between the drill-string and the borehole, which affects the drill-string dynamics. In order to study the influence of such frictional effects on the effectiveness of the AST in improving the rate-of-penetration and drilling efficiency, a model-based approach is proposed. A dynamic model with coupled axial and torsional dynamics of a drilling system including the down-hole tool in an inclined well is constructed. Furthermore, the frictional contact between the drill-string and the borehole is modelled by a set-valued spatial Coulomb friction law affecting both the axial and torsional dynamics. These dynamics are described by state-dependent delay differential inclusions. Numerical analysis of this model shows that the rate-ofpenetration and drilling efficiency increases by inclusion of the AST, both in the case with and without spatial Coulomb friction. Furthermore, a parametric design study of the AST in different inclined drilling scenarios is performed. This study reveals a design for the AST,

Evaluation of Distributed Damping Subs with Active Control for Stick-Slip Reduction in Drilling

“…While passive dampers have the same configuration while downhole, the characteristics of active tools change while drilling to react to the occurring vibrations. The anti-stall tool (Wildemans et al, 2019) is such a passive device that consists of an axial spring and a helical spline. A torsional load screws the tool together, reducing the axial and torsional load on the bit.…”

Axial–Torsional Dynamics of a Drilling Bit with Non-uniform Blade Arrangement

“…It is noteworthy that the goal of this paper is to propose a comprehensive model that can be used for parametric design or active controller design to reduce unwanted vibrations. For example, the proposed model (which is a more comprehensive model) can be used along with the approaches in [17,21,25] for dynamical analysis, parametric design, or design an anti-stall tool for vibration reduction.…”

Drill Bit Stick-Slip Vibration Experiment Research and Analysis of Influencing Factors

“…Therefore, restraining the stick-slip vibration of the drilling system is a major problem in the current drilling engineering. At present, domestic and foreign scholars' research on stick-slip vibration mainly includes three aspects: nonlinear dynamic analysis when stick-slip vibration occurs during drilling, the establishment and solution of the mathematical model of stick-slip vibration, and the design of a soft torque controller to suppress stick-slip vibration [2][3][4][5][6].…”

“…1 Moderately weathered sandstone2 Moderately weathered siltstone3 Moderately weathered argillite4 Weak weathering drive motor. The deformation of the drill column accumulates until it reaches the slippage state and stick-slip vibration occurs.…”