Electromagnetically excited torsional vibration to rock drilling support

2020 ◽  
pp. 1-14
Author(s):  
Tomasz Trawiński ◽  
Marcin Szczygieł ◽  
Arkadiusz Tomas
Keyword(s):  
Mathematical Models ◽  
Torsional Vibration ◽  
Drilling Process ◽  
Torsional Vibrations ◽  
Research Fund ◽  
Incident Response ◽  
European Research ◽  
Rescue Operation ◽  
Drilling Rig ◽  
Drilling System

During a serious underground incident the most important things are the lives of miners and the time necessary for the rescue team to find victims of the accident. The paper presents the concept of a new drilling system that uses torsional vibrations in the drilling process. In the article formulating mathematical models of a drilling rig is one of the tasks of the INDIRES (INformation Driven Incident RESponse) project implemented as a part of the European Research Fund for Coal and Steel. The INDIRES project is dedicated to the task of conducting a rescue operation after accidents in mines.

Torsional Vibrations and Nonlinear Dynamic Characteristics of Drill Strings and Stick-Slip Reduction Mechanism

2019 ◽  
Vol 14 (8) ◽  
Author(s):  
Jialin Tian ◽  
Genyin Li ◽  
Liming Dai ◽  
Lin Yang ◽  
Hongzhi He ◽  
...  
Keyword(s):  
Torsional Vibration ◽  
Nonlinear Dynamic ◽  
Drill String ◽  
Drilling Process ◽  
Drill Bit ◽  
Torsional Vibrations ◽  
Reduction Mechanism ◽  
Nonlinear Dynamic Model ◽  
Stick Slip ◽  
Research Results

Torsional stick–slip vibrations easily occur when the drill bit encounters a hard or a hard-soft staggered formation during drilling process. Moreover, serious stick–slip vibrations of the drill string is the main factor leading to low drilling efficiency or even causing the downhole tools failure. Therefore, establishing the stick–slip theoretical model, which is more consistent with the actual field conditions, is the key point for new drilling technology. Based on this, a new torsional vibration tool is proposed in this paper, then the multidegree-of-freedom torsional vibrations model and nonlinear dynamic model of the drill string are established. Combined with the actual working conditions in the drilling process, the stick–slip reduction mechanism of the drill string is studied. The research results show that the higher rotational speed of the top drive, smaller viscous damping of the drill bit, and smaller WOB (weight on bit) will prevent the stick–slip vibration to happen. Moreover, the new torsional vibration tool has excellent stick–slip reduction effect. The research results and the model established in this paper can provide important references for reducing the stick–slip vibrations of the drill string and improving the rock-breaking efficiency.

Torsional Vibration Analysis of Drillstrings in Blasthole Drilling

2008 ◽  
Author(s):  
Omid Aminfar ◽  
Amir Khajepour
Keyword(s):  
Torsional Vibration ◽  
Natural Frequencies ◽  
Element Model ◽  
Drilling Process ◽  
Torsional Vibrations ◽  
Rotary Drilling ◽  
Well Drilling ◽  
State Response ◽  
Drilling Performance ◽  
Overall Performance

Reducing vibrations in well drilling has a significant effect on improving the overall performance of the drilling process. Vibrations may affect the drilling process in different ways, i.e., reducing durability of the drillstring’s elements, reducing the rate of penetration, and deviating the drilling direction. In rotary drilling, which is used to open mine and oil wells, torsional vibration of the drillstring is an important component of the overall system’s vibration that has received less attention in the literature. In this paper, we propose a finite element model for a sample blasthole drillstring used to open mine wells to investigate its torsional vibrations. Boundary conditions and elements’ specifications are applied to this model. In the model, the interaction between the insert and the rock is represented by a set of repetitive impulses according to the insert pattern. The steady-state response of the system to the repetitive impulses is found and natural frequencies, kinetic energy, and potential energy of the drillstring are calculated. The root mean square (RMS) of the total energy can be used as the measure for reducing the torsional vibration of the system. Finally, an optimum combination of inserts on the cone’s rows was found based on minimizing the total vibratory energy of the drillstring. The optimum design can reduce the torsional vibrations of the drillstring and improve the drilling performance.

scholarly journals Conceptual Control Method of Drilling Rig’s Torsional Vibrations Frequencies

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8403
Author(s):  
Tomasz Trawiński ◽  
Marcin Szczygieł ◽  
Bartosz Polnik ◽  
Przemysław Deja
Keyword(s):  
Torsional Vibration ◽  
Natural Frequencies ◽  
Control Method ◽  
New Technology ◽  
Drilling Process ◽  
Torsional Vibrations ◽  
Drilling Tool ◽  
Laboratory Facility ◽  
Drilling Method ◽  
Drilling Time

This article focuses on the possibility of using an innovative drilling method for the implementation of underground works, especially where there is no physical possibility of using large working machines. Work on a model carried out under the INDIRES project is discussed. A design of a drilling tool equipped with the proposed technology is presented. The solution in question makes it possible to increase the efficiency of the drilling process, which is confirmed by computer simulations. Also, introductory tests of a drilling process supported by torsional vibration generated by an electromagnetic torque generator provided in the KOMAG laboratory facility show the reduction of the drilling time by almost two-fold. In our opinion, adding torsional vibration acting on the plane of a drilled wall that equals natural frequencies of the drilled material represents a promising new technology for drilling. The presented work constitutes the basis for the development of the proposed technology and allows us to conclude that the developed method will be of great interest to manufacturers of drilling machines and devices.

Modelling of the Dynamic Behavior of the Power Transmission of an Automatic Small Scale Drilling Rig

2017 ◽  
Author(s):  
Eric Cayeux ◽  
Hans Joakim Skadsem
Keyword(s):  
Mathematical Models ◽  
Physical System ◽  
Power Transmission ◽  
Drill String ◽  
Laboratory Scale ◽  
Small Scale ◽  
Drilling Process ◽  
Drilling Rig ◽  
Contact Points ◽  
Drilling Conditions

The automatization of the drilling process opens the opportunity to faster reactions in case of unexpected drilling conditions, therefore reducing the risk that a drilling incident escalates to a serious situation. It also allows to push the drilling performance to be as close as possible to the limits of drillability as a function of the varying drilling conditions. But to achieve high level of drilling process automation, it is necessary to have access to accurate mathematical models of the complex physical system that is composed of the drilling rig, the drill-string, the drilling fluid and the borehole itself. As the development of accurate heat transfer, mechanical and hydraulic models and their utilization in full scale drilling applications is a huge and complex task, it is tempting to recreate drilling automatization problems in a laboratory scale setup. Because of sudden variations of the downhole drilling conditions, like when transitioning from soft to hard rock or when the bit is subject to large torque variations induced by interbedded rock layers, the boundary conditions at the bit change suddenly and require quick response from the automatic top-drive and hoisting system controllers. At a small laboratory scale, the necessary reaction times are of the order of milliseconds and therefore exclude any manual intervention. It is therefore crucial that the automatic control methods utilize precise mathematical models of the physical system to accurately estimate the limits by which the drilling process can be managed under safe conditions. For that reason, a general purpose mathematical model of small-scale drilling rigs has been developed. First, the Rayleigh-Ritz method is used to determine the deflection of the drill-string and to estimate the side forces at the contact points along the drill-string and BHA (Bottom Hole Assembly). Then the dynamic response of the power transmission system is modelled for both variable frequency drive controlled tri-phase motors and for stepper motors, including friction effects at the contact points. Friction is modelled using Stribeck theory rather than the classical Coulomb laws of friction. Finally, the expected response of 3D accelerometers, that could be placed on the outside of a BHA component, is modelled to retrieve possible inclination variations and potential vibration modes such as torsional oscillations, forward or backward whirl. The generality of the model is such that it can be used for many small-scale drilling rig designs.

scholarly journals Hybrid sliding PID controller for torsional vibrations mitigation in rotary drilling systems

2021 ◽  
Vol 22 (1) ◽  
pp. 146
Author(s):  
Chafiaa Mendil ◽  
Madjid Kidouche ◽  
Mohamed Zinelabidine Doghmane
Keyword(s):  
Pid Controller ◽  
Sliding Mode ◽  
Research Work ◽  
Drilling Process ◽  
Torsional Vibrations ◽  
Rotary Drilling ◽  
Stick Slip ◽  
Dynamical Interaction ◽  
Drilling System ◽  
Slip Phenomenon

During the drilling process, the drilling system devices can be exposed to several types of phenomena incited by lateral, axial, and torsional vibrations. The latter can lead to severe damages if they are not efficiently controlled and quickly mitigated. This research work is focused on the torsional vibrations, which are stimulated by the nonlinear dynamical interaction between the geological rocks and the drill bit. Wherein, a model with three degrees of freedom was designed to demonstrate the severity of the stick-slip phenomenon as consequence of torsional vibrations. The main objective of this study was to design a robust controller based on hybridizing a conventional PID controller with sliding mode approach in order to mitigate rapidly the torsional vibrations. Moreover, a comparative study between PI, PID and sliding mode controllers allowed us to emphasize the effectiveness of the new hybrid controller and improve the drilling system performances. Furthermore, the chattering phenomenon in the sliding surface was overcome by using the saturation function rather than the sign function. The obtained results proved the usefulness of the proposed controller in suppressing the stick-slip phenomenon for smart industrial drilling systems.

scholarly journals VIBRATIONS AND STABILITY OF A GEOMETRICALLY NONLINEAR WEIGHTY DRILL STRING FOR DRILLING OIL AND GAS WELLS

2021 ◽  
Vol 2 (446) ◽  
pp. 6-14
Author(s):  
S. М. Akhmetov ◽  
M. Diarov ◽  
N. М. Akhmetov ◽  
D. T. Bizhanov ◽  
Zh. K. Zaidemova
Keyword(s):  
Oil And Gas ◽  
Drill Pipe ◽  
Nonlinear Problems ◽  
Physical Nonlinearity ◽  
Drill String ◽  
Contact Forces ◽  
Drilling Process ◽  
Geometrically Nonlinear ◽  
Drilling Rig ◽  
Drilling System

Heavy weight drill pipe (HWDP) in wells are hollow, weighty rods with stepwise changing physical properties (for example, stiffness), and each link of the string can deform according to geometrically nonlinear laws. They are the most critical part in the drilling process, transmitting power from the drilling rig to the rock failing tool, and are in hydrodynamic and contact interaction with the borehole walls, and are always curved. This occurs due to the curvature of the well itself, and under the action of its own weight, contact forces, as well as centrifugal forces in the case of rotation of the pipe. In this case, the curvature of the HWDP axis can be significantly influenced by the geometric nonlinearity of the deformation of its pipes. A review of this issue revealed a number of poorly studied problems, which include accounting for both phy- sically and geometrically nonlinear problems, accompanied by various types of complications (loss of stability HDWP, pipe breaks, etc.), as well as other processes in the elements of a dynamic drilling system (DDS). In this paper, based on the use of modern methods for studying dynamic processes in mechanical systems, a method is proposed for studying longitudinal oscillations of a geometrically nonlinear HWDP of its stability under torsion, taking into account the physical nonlinearity in the process of its deformation. The dependences characte- rizing this process are found.

scholarly journals Autonomous Decision-Making While Drilling

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 969
Author(s):  
Eric Cayeux ◽  
Benoît Daireaux ◽  
Adrian Ambrus ◽  
Rodica Mihai ◽  
Liv Carlsen
Keyword(s):  
Decision Making ◽  
Internal State ◽  
Drilling Process ◽  
Autonomous Decision ◽  
Internal States ◽  
Markov Decision ◽  
Drilling Operations ◽  
Drilling System ◽  
Drilling Conditions ◽  
Erratic Behavior

The drilling process is complex because unexpected situations may occur at any time. Furthermore, the drilling system is extremely long and slender, therefore prone to vibrations and often being dominated by long transient periods. Adding the fact that measurements are not well distributed along the drilling system, with the majority of real-time measurements only available at the top side and having only access to very sparse data from downhole, the drilling process is poorly observed therefore making it difficult to use standard control methods. Therefore, to achieve completely autonomous drilling operations, it is necessary to utilize a method that is capable of estimating the internal state of the drilling system from parsimonious information while being able to make decisions that will keep the operation safe but effective. A solution enabling autonomous decision-making while drilling has been developed. It relies on an optimization of the time to reach the section total depth (TD). The estimated time to reach the section TD is decomposed into the effective time spent in conducting the drilling operation and the likely time lost to solve unexpected drilling events. This optimization problem is solved by using a Markov decision process method. Several example scenarios have been run in a virtual rig environment to test the validity of the concept. It is found that the system is capable to adapt itself to various drilling conditions, as for example being aggressive when the operation runs smoothly and the estimated uncertainty of the internal states is low, but also more cautious when the downhole drilling conditions deteriorate or when observations tend to indicate more erratic behavior, which is often observed prior to a drilling event.

Study of stick–slip suppression and robustness to parametric uncertainty in drill strings containing torsional vibration tool using sliding-mode control

2021 ◽  
pp. 146441932110452
Author(s):  
Jialin Tian ◽  
Jie Wang ◽  
Siqi Zhou ◽  
Yinglin Yang ◽  
Liming Dai
Keyword(s):  
Torsional Vibration ◽  
Complex Dynamics ◽  
Sliding Mode ◽  
Parametric Uncertainty ◽  
Drill String ◽  
Lumped Parameter Model ◽  
Drilling Process ◽  
Drill Bit ◽  
Stick Slip ◽  
Drilling Operations

Excessive stick–slip vibration of drill strings can cause inefficiency and unsafety of drilling operations. To suppress the stick–slip vibration that occurred during the downhole drilling process, a drill string torsional vibration system considering the torsional vibration tool has been proposed on the basis of the 4-degree of freedom lumped-parameter model. In the design of the model, the tool is approximated by a simple torsional pendulum that brings impact torque to the drill bit. Furthermore, two sliding mode controllers, U1 and U2, are used to suppress stick–slip vibrations while enabling the drill bit to track the desired angular velocity. Aiming at parameter uncertainty and system instability in the drilling operations, a parameter adaptation law is added to the sliding mode controller U2. Finally, the suppression effects of stick–slip and robustness of parametric uncertainty about the two proposed controllers are demonstrated and compared by simulation and field test results. This paper provides a reference for the suppression of stick–slip vibration and the further study of the complex dynamics of the drill string.

Transient and Unstable Torsional Vibrations on a 4-Stroke Marine Diesel Engine

2003 ◽  
Author(s):  
D. C. Lee ◽  
J. D. Yu
Keyword(s):  
Diesel Engine ◽  
Torsional Vibration ◽  
Marine Diesel Engine ◽  
Torsional Vibrations ◽  
Steady State Condition ◽  
Marine Propulsion ◽  
Friction Clutch ◽  
Marine Diesel ◽  
Noise Measurements ◽  
Unstable Vibration

Under steady state condition, unstable torsional vibration normally does not occur in shafting systems using 4stroke diesel engine due to hysteresis damping of shafting system and relative damping of standard fitted damper. However, the unstable torsional vibration occurs on marine propulsion shafting systems due to slippage of a multi-friction clutch installed between increasing gear box and shaft generator. To identify this unstable vibration and make proper counter measure, the simulation for transient torsional vibration using the Newmark method is introduced in this paper. The mechanism of this unstable vibration is verified by vibration and noise measurements of the shafting system.

Effect of Axial and Torsional Vibrations on Tapping Performance

2016 ◽  
Vol 826 ◽  
pp. 88-92
Author(s):  
Swapnil Pawar ◽  
Sandip Patil ◽  
Pravin Pawar ◽  
Rajkumar Singh
Keyword(s):  
Titanium Alloys ◽  
Torsional Vibration ◽  
Torsional Vibrations ◽  
Taguchi Approach ◽  
Maximum Torque ◽  
Degree Of Reduction

Abrupt breakage of the taps is frequently encountered during tapping threads, especially when tapping on ‘difficult-to-cut’ material like titanium. This work therefore presents an extensive experimentation with the Taguchi approach to investigate maximum torque in tapping on titanium alloys while performing axial and, axial and torsional vibration-assisted tapping (AVAT and ATVAT). The experimentation shows that both AVAT and ATVAT reduce the tapping torqueduring tapping as compared to that of in conventional tapping process. However, ATVAT process had exhibited a higher degree of reduction in torque when compared to AVAT process.

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