Modeling and Investigation of the Velocity-Dependent Cutting Process with PDC Cutters Using the Discrete Element Method

Fu, Zhiyi; Ostermeyer, Georg-Peter; Kueck, Armin; Schiefer, Frank; Reckmann, Hanno; Huang, Xu; Bomidi, John

doi:10.1155/2023/6381319

Cited by 3 publications

(2 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…α sh is the shoulder angle. According to Figure 6, the lengths of the cutting blades (30) are given by the distances between the points defined by Equation (29).…”

Section: Coordinate Systems and Geometrical Variablesmentioning

confidence: 99%

“…This approach is well suited to describe the different bit-cutter configurations. Fu et al [28,29] extended and modified this modelling approach to investigate the velocity-dependent cutting process using DEM simulations. The parameter studies that have been carried out show possibilities of mitigating self-excited drill string vibrations by changing operating states or cutter design.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A Novel Mesoscopic Drill Bit Model for Deep Drilling Applications

2023

View full text Add to dashboard Cite

This paper deals with the development of a novel mesoscopic model of polycrystalline diamond compact (PDC) drill bits that can be implemented in complex drill string models for simulations to analyse the influence of rock inhomogeneities or the impact of anti-whirl bits on drill string dynamics. In contrast to existing modelling approaches, the model is developed at a mesoscopic level, where the basic bit–rock interaction is taken from the macroscopic bit model and the cutting characteristics are summarised at a microscopic cutting level into a simplified configuration via cutting blades. This model can therefore effectively describe asymmetries and thus interactions between the torsional and lateral dynamics of the drill bit, and is particularly suitable for investigating the effects of drilling into rock inhomogeneities and fault zones on drilling dynamics. By integration into a complex drill string model, simulation studies of drilling through a sandwich formation were carried out. The simulation results allow detailed stability statements and show the influence of formation properties and bit design on torsional and lateral drill string dynamics.

show abstract

“…α sh is the shoulder angle. According to Figure 6, the lengths of the cutting blades (30) are given by the distances between the points defined by Equation (29).…”

Section: Coordinate Systems and Geometrical Variablesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A Novel Mesoscopic Drill Bit Model for Deep Drilling Applications

2023

View full text Add to dashboard Cite

show abstract

On the mechanism of rock fracture with tools made of hard alloys and polycrystalline superhard materials

Krasnyk

2023

Geoteh. meh.

View full text Add to dashboard Cite

When studying the process of rock fracture with tools equipped with polycrystalline superhard materials (PSHM) and hard alloys, the main regularities of the fracture mechanism, despite the significant differences in physical and mechanical properties of the used tool materials, are assumed to be identical. This approach not only reduces the efficiency of using the created rock-destroying tools, but also limits the scope of application of polycrystalline superhard materials. Experimental studies using various methods of obtaining information shown significant differences in the mechanism of rock fracture by hard alloys and polycrystalline superhard materials. The study of the zone of the pre-destroyed surface showed that when cutting rocks with PSTM, the process of destruction is carried out not only by the entire polycrystalline plate, but also by ridged diamond formed on the cutting edge and rear surface of the tool. At the same time ridged diamonds, when embedded in the rock, create high contact stresses and an additional network of microcracks interacting with microcracks formed due to the embedding of the entire cutting edge of the plate. The impact of two independent indenters simultaneously increases the zone of the pre-destruction layer in the rock mass, which leads to a more significant decrease in its strength and, as a consequence, to the intensification of the process of rock destruction by the PSTM tool. In case of wrong choice of PSTM application area and operation modes, errors in tool design and insufficient cooling, ridges are not formed on the cutting edge and back surface of the polycrystal. As a result, the polycrystalline insert works as a carbide insert and the efficiency of the PSHM tool is sharply reduced. The use of knowledge obtained as a result of the conducted research makes it possible to create tools equipped with diamond-hard-alloyed inserts, the wear resistance of which is dozens of times higher than that of similar tools made of hard alloy. For example, effective tools equipped with diamond-hard-alloyed inserts have been created and widely introduced into practice for rotary drilling of boreholes, degassing wells, anchoring of mine workings, saw stone cutting, drilling of abrasive permafrost soils and others. Keywords: polycrystalline diamonds cutters (PDC), hard alloys, pre-destruction zone, rock breaking tools, rock destruction.

show abstract

The Nature of the Interaction Between Bit-Whirl and High-Frequency Torsional Oscillations

Hohl,

Kueck,

Kulke

et al. 2024

Day 1 Mon, February 12, 2024

View full text Add to dashboard Cite

High-Frequency Torsional Oscillations (HFTO) are bit induced self-excited vibrations which can cause downhole tool failures and reduce the reliability of downhole tools. It is essential to understand the interaction of HFTO with other vibrational phenomena to develop effective HFTO mitigation strategies. While coupling with axial vibrations and stick-slip have already been studied extensively, the interaction of HFTO with lateral vibrations has received less attention. This paper analyzes this interaction based on a bit rock interaction model that accounts for the superimposed movement of whirl and HFTO at the bit. The excitation of HFTO can be attributed to a velocity-dependent characteristic of the cutting torque. A model that incorporates the superposition of lateral and torsional movement at the bit is used to calculate the velocity-dependent bit torque based on three components: the cutting velocity at each cutter, the normal force distribution along bit blades, and velocity-dependent forces between the bit and the rock. The velocity distribution is based on a kinematic model that superimposes the lateral motion of whirling and the rotational motion of HFTO. The normal force distribution is derived from the bit blade and cutter configuration, and the velocity-dependent force characteristics at each bit element is based on findings of laboratory tests with single cutting elements. A continuous multivariable function determines the nonlinear drilling torque characteristic depending on the amplitudes of HFTO and backward whirl. Evaluation of the simulated drilling torque shows that HFTO cannot be excited in presence of bit backward whirl. Specifically, it was found that an increasing rate of bit backward whirl leads to a bit torque characteristic generating less energy input or even energy output to HFTO. This is caused by backwards cutters with negative cutting torques corresponding to high energy dissipation. Forward whirl, on the other hand, cannot suppress HFTO. Comparison with laboratory data confirms these results. Cutter geometry and normal force distribution do not appear to have a significant effect on the results in either case. The new bit model provides a physics-based explanation of why bit backward whirl and torsional vibrations cannot be observed simultaneously. The influence of parameters, like the cutting-edge geometry, can be evaluated much faster than, for example, with particle or finite element models.

show abstract

Modeling and Investigation of the Velocity-Dependent Cutting Process with PDC Cutters Using the Discrete Element Method

Cited by 3 publications

References 30 publications

A Novel Mesoscopic Drill Bit Model for Deep Drilling Applications

A Novel Mesoscopic Drill Bit Model for Deep Drilling Applications

On the mechanism of rock fracture with tools made of hard alloys and polycrystalline superhard materials

The Nature of the Interaction Between Bit-Whirl and High-Frequency Torsional Oscillations

Contact Info

Product

Resources

About