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.

Drilling Cutting Analysis to Assist Drilling Performance Evaluation in Hard Rock Hole Widening Operation

2020 ◽  
Author(s):  
Daiyan Ahmed ◽  
Yingjian Xiao ◽  
Jeronimo de Moura ◽  
Stephen D. Butt
Keyword(s):  
Performance Enhancement ◽  
Ore Deposits ◽  
Drilling Process ◽  
Rotary Drilling ◽  
Pilot Hole ◽  
Drilling Rig ◽  
Drilling Performance ◽  
Drilling Parameters ◽  
Weight On Bit ◽  
Drilling Operations

Abstract Optimum production from vein-type deposits requires the Narrow Vein Mining (NVM) process where excavation is accomplished by drilling larger diameter holes. To drill into the veins to successfully extract the ore deposits, a conventional rotary drilling rig is mounted on the ground. These operations are generally conducted by drilling a pilot hole in a narrow vein followed by a hole widening operation. Initially, a pilot hole is drilled for exploration purposes, to guide the larger diameter hole and to control the trajectory, and the next step in the excavation is progressed by hole widening operation. Drilling cutting properties, such as particle size distribution, volume, and shape may expose a significant drilling problem or may provide justification for performance enhancement decisions. In this study, a laboratory hole widening drilling process performance was evaluated by drilling cutting analysis. Drill-off Tests (DOT) were conducted in the Drilling Technology Laboratory (DTL) by dint of a Small Drilling Simulator (SDS) to generate the drilling parameters and to collect the cuttings. Different drilling operations were assessed based on Rate of Penetration (ROP), Weight on Bit (WOB), Rotation per Minute (RPM), Mechanical Specific Energy (MSE) and Drilling Efficiency (DE). A conducive schedule for achieving the objectives was developed, in addition to cuttings for further interpretation. A comprehensive study for the hole widening operation was conducted by involving intensive drilling cutting analysis, drilling parameters, and drilling performance leading to recommendations for full-scale drilling operations.

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.

Simulation of Torsional Vibrations or Multibody Simulation: Which Technique Does the Wind Power Industry Need for Solving the Present-Day Problems?

2003 ◽  
Author(s):  
Berthold Schlecht ◽  
Tobias Schulze ◽  
Jens Demtro¨der
Keyword(s):  
Torsional Vibration ◽  
Natural Frequencies ◽  
Wind Load ◽  
Operating Conditions ◽  
Drive Train ◽  
Torsional Vibrations ◽  
Multibody Simulation ◽  
Vibration Behavior ◽  
Drive Trains ◽  
Load Simulation

For the simulation of service loads and of their effect on the whole turbine the wind turbine manufacturers use program systems whose particular strengths lie in the wind load simulation at the rotor, in the rotor dynamics as well as in the control-technological operation of the whole turbine. The complex dynamic behavior of the drive train, consisting of the rotor, the rotor shaft, the main gearbox, the brake, the coupling and the generator, is represented as a two-mass oscillator. This simplification, which certainly is necessary within the framework of the wind load simulation programs, is by no means sufficient for the exact description of the dynamics of the more and more complex drive trains with capacities up to 5 MW. At first, the extension to a multimass torsional vibration model seems to be useful for the exact determination of the torsional vibrations in the drive train. However, in the turbines of all manufacturers there have been found forms of damage on drive train components (high axial loads in bearings, high coupling loads, radial loads on generator bearings) that cannot be explained even on the basis of a torsional vibration analysis. Moreover, in measurements on drive trains natural frequencies in the signals occurred that can no longer be explained by the torsional vibration behavior alone. Consequently, a real multibody simulation becomes necessary, for which also radial and axial vibrations can be taken into account, in addition to torsion, since these influence the torsional vibration behavior considerably. These dependences become already clear in an analysis of natural frequencies. This is illustrated by the example of a 700-kW turbine as well as by a planetary gearing for a 3-MW turbine. Especially in the dimensioning of the off-shore turbines with several MW output power, which are being planned, the use of multibody simulation will be advantageous, since the testing of turbine prototypes of this order of magnitude under the corresponding operating conditions are surely more cost-intensive and risky than the virtual testing with well validated simulation models.

Application of Four-Pole Parameters to Torsional Vibration Problems

1962 ◽  
Vol 84 (1) ◽  
pp. 21-34 ◽  
Author(s):  
C. T. Molloy
Keyword(s):  
Equivalent Circuit ◽  
Torsional Vibration ◽  
Natural Frequencies ◽  
Distributed Parameter Systems ◽  
Distributed Parameter ◽  
Torsional Vibrations ◽  
Electrical Circuits ◽  
Angular Velocities ◽  
Vibration Problems ◽  
Pole System

This paper deals with the application of the method of four-pole parameters to torsional vibrations. Results are developed from fundamental principles. The four-pole parameters for the basic rotational elements are derived. These include shafts (both lumped and distributed-parameter cases), disks, dampers, and gears. The equations which must be obeyed, when these elements are connected, are presented. The application to construction of equivalent electrical circuits is given and in particular a method for constructing the equivalent circuit of distributed-parameter systems is put forth. The torsional analogs of Thevenin’s and Norton’s theorems are given for rotational sources. The fundamentals mentioned above are then applied to the following problems: (a) The effect of substituting one four-pole for another in a torsional system. (b) The effect of opening a four-pole system and inserting a new four-pole between the separated four-poles. (c) Calculation of all the torques and angular velocities in a tandem system. (d) Calculation of natural frequencies of undamped four-pole systems.

Computer Method for Forced Torsional Vibration of Propulsive Shafting System of Marine Engine With or Without Damping

1982 ◽  
Vol 26 (03) ◽  
pp. 176-189
Author(s):  
Jong-Shyong Wu ◽  
Wen-Hsiang Chen
Keyword(s):  
Torsional Vibration ◽  
Natural Frequencies ◽  
Computer Programs ◽  
Computer Method ◽  
Mode Shapes ◽  
Torsional Vibrations ◽  
Preliminary Design ◽  
Slide Rule ◽  
Output Data ◽  
The Mean

In the preliminary design of a propulsive shafting system, the additional (vibratory) stress due to torsional vibration is one of the important factors that must be considered in addition to the mean stress induced by the steady torque. In this paper, existing information concerning shaft design is reviewed; procedures formerly performed by slide rule, diagrams, and tabulations are formulated; and, based on the induced formulas, computer programs are developed. For an engine either two cycle or four cycle, single cylinder or multicylinder, and for a shafting system either undamped or damped (inner or outer or both inner and outer), it is required only to change the input data to obtain the desired data for various order numbers of torsional vibrations due to various firing orders of the cylinders. The output data include the natural frequencies and the corresponding mode shapes of the torsional vibrations, the amplitudes of twisting angles, and the vibratory stresses of the shafts. The reliability of the induced formulas and the developed computer programs has been confirmed by agreement between the computer output and existing information.

Physics-based Rate of Penetration Prediction Model for Fixed Cutter Drill Bits

2020 ◽  
pp. 1-12
Author(s):  
Jeronimo de Moura Junior ◽  
Jianming Yang ◽  
Stephen D. Butt
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Low Complexity ◽  
Field Trials ◽  
Drilling Process ◽  
Rotary Drilling ◽  
Rate Of Penetration ◽  
Drilling Performance ◽  
Drill Bits ◽  
Proposed Model

Abstract The drilling process is one of the most important and expensive aspects of the oil and gas industry. In consequence, an accurate prediction of the rate of penetration (ROP) is crucial to the optimization of drilling performance and thus, contributes directly to reducing drilling costs. Knowledge of drilling performance is a vital tool in the development of a consistent drilling plan and allows industry players to anticipate issues that may occur during a drilling operation. Several approaches to predict the drilling performance have been tried with varying degrees of success, complexity and accuracy. In this paper, a review of the history of drilling performance prediction is conducted with emphasis on rotary drilling with fixed cutter drill bits. The approaches are grouped into two categories: physics-based and data-driven models. The paper's main objective is to present an accurate model to predict the drilling performance of fixed cutter drill bits including the founder point location. This model was based on a physics-based approach due to its low complexity and good accuracy. This development is based on a quantitative analysis of drilling performance data produced by laboratory experiments. Additionally, the validation and applicability tests for the proposed model are discussed based on DOTs and field trials in several different drilling scenarios. The proposed model presented high accuracy to predict the fixed cutter drill bit drilling performance in the twenty-seven different drilling scenarios which were analyzed in this paper.

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.

Adaptive Electromagnetic Torsional Tuned Vibration Absorber and its Application in Rotating Equipment

2012 ◽  
Author(s):  
Taher Abu Seer ◽  
Nader Vahdati ◽  
Hamad Karki ◽  
Oleg Shiryayev
Keyword(s):  
Natural Frequency ◽  
Torsional Vibration ◽  
Natural Frequencies ◽  
Vibration Reduction ◽  
Vibration Absorber ◽  
Torsional Vibrations ◽  
Wide Range ◽  
Simulation Results ◽  
Rotating Equipment ◽  
Tuned Vibration Absorber

Rotating equipment is susceptible to torsional vibrations whenever the RPM of the rotating equipment matches one of the torsional natural frequencies. For rotating equipment running at constant RPM, it is easy to control and mitigate the torsional vibrations, but in applications where the RPM is no longer a constant and varies widely or natural frequencies are changing: there is a need for a wide range vibration reduction device. In this paper, a translational adaptive electromagnetic tuned vibration absorber (ETVA) is described where its natural frequency is varied using electronics. The ETVA is modeled and its simulation results correlate very well with experimental results. Later, this concept is used to develop a torsional tuned vibration absorber (TTVA) device. The electromagnetic TTVA can be attached to rotating equipment to control torsional vibrations. The electromagnetic TTVA adapts itself and controls the torsional vibrations as and when the RPM varies. Here in this paper, the rotating equipment and the electromagnetic TTVA are modeled. Analysis results indicate that the torsional vibration of rotating equipment can be easily controlled using this newly developed electromagnetic TTVA.

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.

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