Analysis of Postbucking Drillstring Vibrations in Rotary Drilling of Extended-Reach Wells

2009 ◽  
Author(s):  
Vadim S. Tikhonov ◽  
Alexander I. Safronov
Keyword(s):  
Angular Velocity ◽  
Dynamic Model ◽  
Dynamic Behavior ◽  
Friction Force ◽  
Normal Component ◽  
Method Of Lines ◽  
Force Model ◽  
Nonlinear Dynamic Model ◽  
Rotary Drilling ◽  
Lift Off

One of the most serious concerns of extended-reach drilling is the dynamic behavior of the drillstring and cleaning of well. Good cleaning requires an increased angular speed. However, at higher rotary speeds, the drill string sections lying on the borehole horizontal sections tend to buckle, first, in the form of “snake”, sliding up and down the borehole bottom wall, and then in the form of whirling as the angular velocity increases. This paper presents the 3D nonlinear dynamic model of drillstring in a wellbore of 3D profile. The model suggests the possible contact/lift-off of drill pipes with/from the wellbore wall. The interaction of lateral, torsion and axial vibrations is taken into account. The relation between the normal component of contact force and the deformation of the wellbore wall is taken as quadratic-elastic. The friction force is described based on a hysteretic dynamic model. The friction force model also takes into account the transition from a sliding to a whirling. The equations of the drillstring dynamics are solved numerically using the method of lines. The DYNTUB computer program is developed to analyze the drillstring time-varying processes under different loading. The program is used to study the effects of the angular velocity, compression load, torque, friction factor, well profile, and availability of connectors on the drillstring dynamic behavior.

Analysis of Postbuckling Drillstring Vibrations in Rotary Drilling of Extended-Reach Wells

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Vadim S. Tikhonov ◽  
Alexander I. Safronov
Keyword(s):  
Angular Velocity ◽  
Friction Factor ◽  
Dynamic Model ◽  
Dynamic Behavior ◽  
Friction Force ◽  
Contact Force ◽  
Normal Component ◽  
Method Of Lines ◽  
Force Model ◽  
Nonlinear Dynamic Model

One of the most serious concerns of extended-reach drilling is the dynamic behavior of the drillstring and the cleaning of well. Good cleaning requires an increased angular velocity. This paper presents a 3D nonlinear dynamic model of drillstring in a wellbore of 3D profile. The model suggests possible contact/lift-off of drill pipes with/from the wellbore wall. The interaction of lateral, torsional, and axial vibrations is taken into account. The relation between the normal component of contact force and the deformation of the wellbore wall is taken as quadratic-elastic. The friction force is described based on a hysteretic dynamic model. The friction force model also takes into account, the transition from a sliding to whirling. The equations of drillstring dynamics are solved numerically using the method of lines. The DYNTUB software is developed to analyze the drillstring time-varying processes under different loads. The program is used to study the effects of angular velocity, compression load, torque, friction factor, well profile, and availability of connectors on the drillstring dynamic behavior. From the study follows the key conclusions: (1) The friction factor has a considerable effect on the drillstring rotational behavior in the wellbore; (2) no whirling of drillstring at real value of rolling friction factor in a horizontal well in the discussed examples could be seen at all; (3) when whirling takes place, the contact force shows a dramatic times increase; and (4) snaking can be seen in any wells at moderate compressive load and angular velocity.

An Improved Nonlinear Dynamic Model of Gear Transmission

2007 ◽  
Author(s):  
Jinyuan Tang ◽  
Siyu Chen ◽  
Changjiang Zhou
Keyword(s):  
Frequency Response ◽  
Dynamic Model ◽  
Friction Force ◽  
Nonlinear Dynamic ◽  
Nonlinear Models ◽  
Harmonic Balance Method ◽  
Gear Transmission ◽  
Force Model ◽  
Nonlinear Dynamic Model ◽  
Gear Mesh

This paper develops a new nonlinear dynamic model of gear transmission on the basis of combining friction, gear mesh stiffness and backlash. In calculating friction force, the dynamic distribution of the load along the actual line of action is taken into consideration. A new period-enlargement method is proposed to set up a friction force model and a gear meshing stiffness model. The non-linear dynamic model is a non-autonomous system. Compared with the former models, the damping coefficient and stiff coefficient in this model developed by the period enlargement method is a periodic function with the same period. Thus it is easier to apply EM (energy method) or other methods for finding the approximate analytical solution of the gear transmission dynamic equations combining with time-varying damping and stiffness. Frequency response function of the nonlinear dynamic model is obtained by using harmonic balance method. Compared the analytic and numerical results of the improved nonlinear model with that of the nonlinear models in the published papers, it is shown that: (a) the former numerical simulation techniques may not work or may result in misleading answers; (b) the coexistence of several different periodic solutions and various impacts are the same with the results in formerly published papers when gear parameters are the same. Finally, the accurate solutions of all three regimes are combined to obtain the overall frequency response of the gear pair.

scholarly journals Analysis of dynamic characteristics for momentum wheel assembly with joint clearance

2018 ◽  
Vol 10 (12) ◽  
pp. 168781401881891
Author(s):  
Qi Wan ◽  
Geng Liu ◽  
Haitao Shi ◽  
Xiaofeng Zhang ◽  
Xin Ning
Keyword(s):  
Friction Coefficient ◽  
Angular Velocity ◽  
Dynamic Model ◽  
Contact Force ◽  
Dynamic Characteristics ◽  
Angular Acceleration ◽  
Friction Model ◽  
Joint Clearance ◽  
Force Model ◽  
Coulomb’S Friction

To study the effects of joint clearance on the dynamic characteristics of the momentum wheel assembly of satellite antennas, the computational dynamic model of momentum wheel assembly is developed in this article, considering influencing factors including rotor imbalance, flexibility, and joint clearance between rotor and bearing. The nonlinear contact force model and modified Coulomb’s friction model are adopted in the joint clearance of the dynamic model, and then the influence of clearance size, driving angular velocity, and friction coefficient on the dynamic behaviors of momentum wheel assembly is further analyzed. The results indicate that the existence of joint clearance has extraordinary obvious effects on the dynamic system characteristics, which causes the adjusting time to reach a state of continuous fluctuation to become longer compared to that of the ideal joint, and the angular acceleration and contact force appear to have high impulse peaks. The larger the clearance, the more obvious the fluctuation amplitude of the response and the slighter the shaking frequency. Furthermore, increasing the driving angular velocity can cause system oscillation with high frequency and large amplitude. Moreover, the smaller the friction coefficient, the poorer the accuracy and stability of the system, which leads to deviation from ideal performance. Therefore, it is important to consider the joint clearance to predict the dynamic characteristics of momentum wheel assembly.

Dynamic analysis for vertical soft landing of reusable launch vehicle with landing strut flexibility

2018 ◽  
Vol 233 (4) ◽  
pp. 1377-1396 ◽  
Author(s):  
Shuai Yue ◽  
Hong Nie ◽  
Ming Zhang ◽  
Mingyang Huang ◽  
He Zhu ◽  
...  
Keyword(s):  
Dynamic Model ◽  
Friction Force ◽  
Coupling Model ◽  
Launch Vehicle ◽  
Force Model ◽  
Soft Landing ◽  
Inertia Moment ◽  
Reusable Launch Vehicle ◽  
Beam Type ◽  
Tip Mass

Based on oleo-honeycomb dampers, a 6-DOF vertical soft landing dynamic model for reusable launch vehicle considering landing strut flexibility is constructed. In order to better analyze the lateral deflection and friction force of the “cantilever beam” type landing strut, a new model for strut is incorporated. Static analysis is first performed based on the rotation angle compatibility equations to attain the equivalent inertia moment. Then the strut lateral vibration model and friction force model are obtained by simplifying it as viscoelastic beam with a tip mass. After that, the ADAMS models are established to perform the comparison and verification analysis of the 6-DOF dynamic model. The results show that the results of 6-DOF dynamic model can approximately approach to the results of rigid-flex coupling model established in ADAMS. Furthermore, the research of the influence of assembly gap between cylinders and bearings, bearing’s elastic modulus, friction coefficient and initial overlapping length on the vehicle landing performance is carried out. The results show that each parameter has different influence on the landing performance, and a reasonable selection of these parameters accordingly enables a higher landing performance.

scholarly journals Nonlinear Dynamics and Analysis of a Planar Multilink Complex Mechanism with Clearance

2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
Author(s):  
Xiulong Chen ◽  
Shuai Jiang ◽  
Yu Deng ◽  
Qing Wang
Keyword(s):  
Nonlinear Dynamics ◽  
Dynamic Response ◽  
Phase Diagrams ◽  
Dynamic Model ◽  
Dynamic Behavior ◽  
Nonlinear Dynamic ◽  
Lagrange Equation ◽  
Nonlinear Dynamic Model ◽  
Planar Mechanism ◽  
Driving Speed

In order to understand the nonlinear dynamic behavior of a planar mechanism with clearance, the nonlinear dynamic model of the 2-DOF nine-bar mechanism with a revolute clearance is proposed; the dynamic response, phase diagrams, Poincaré portraits, and largest Lyapunov exponents (LLEs) of mechanism are investigated. The nonlinear dynamic model of 2-DOF nine-bar mechanism containing a revolute clearance is established by using the Lagrange equation. Dynamic response of the slider’s kinematics characteristic, contact force, driving torque, shaft center trajectory, and the penetration depth for 2-DOF nine-bar mechanism are all analyzed. Chaos phenomenon existed in the mechanism has been identified by using the phase diagrams, the Poincaré portraits, and LLEs. The effects of the different clearance sizes, different friction coefficients, and different driving speeds on dynamic behavior are studied. Bifurcation diagrams with changing clearance value, friction coefficient, and driving speed are drawn. The research could provide important technical support and theoretical basis for the further study of the nonlinear dynamics of planar mechanism.

scholarly journals Non-smooth dynamic modeling and simulation of an unmanned bicycle on a curved pavement

2022 ◽  
Vol 43 (1) ◽  
pp. 93-112
Author(s):  
Kaiming Zhang ◽  
Xudong Zheng ◽  
Zhang Chen ◽  
Bin Liang ◽  
Tianshu Wang ◽  
...  
Keyword(s):  
Dynamic Model ◽  
Friction Force ◽  
Contact Force ◽  
Contact Point ◽  
Rigid Bodies ◽  
Contact Forces ◽  
Force Model ◽  
Lagrange Equations ◽  
Stick Slip ◽  
Normal Contact

AbstractThe non-smooth dynamic model of an unmanned bicycle is established to study the contact-separate and stick-slip non-smooth phenomena between wheels and the ground. According to the Carvallo-Whipple configuration, the unmanned bicycle is reduced to four rigid bodies, namely, rear wheel, rear frame, front fork, and front wheel, which are connected by perfect revolute joints. The interaction between each wheel and the ground is simplified as the normal contact force and the friction force at the contact point, and these forces are described by the Hunt-Crossley contact force model and the LuGre friction force model, respectively. According to the characteristics of flat and curved pavements, calculation methods for contact forces and their generalized forces are presented. The dynamics of the system is modeled by the Lagrange equations of the first kind, a numerical solution algorithm of the dynamic equations is presented, and the Baumgarte stabilization method is used to restrict the drift of the constraints. The correctness of the dynamic model and the numerical algorithm is verified in comparison with the previous studies. The feasibility of the proposed model is demonstrated by simulations under different motion states.

Simulation on Vibration Friction Mechanism of Vibration Pile System

2013 ◽  
Vol 365-366 ◽  
pp. 416-419
Author(s):  
Yun Nan Teng ◽  
Jia Li ◽  
Li Yang Xie ◽  
Bang Chun Wen
Keyword(s):  
Numerical Simulation ◽  
Dynamic Model ◽  
Friction Force ◽  
Nonlinear Dynamic ◽  
Excitation Amplitude ◽  
Nonlinear Dynamic Model ◽  
Friction Mechanism ◽  
Soil System ◽  
Friction Pile

Vibratory pile drivers are widely used in mechanical industry field. In this paper, the nonlinear dynamic model of vibration friction pile-soil system considering the soil friction force is proposed. By numerical simulation, the dynamics characteristics of vibration friction for pile-soil system were obtained. The results showed that with the increasing of excitation amplitude and frequency, the displacement of the pile and frame are both increased.

Analysis of Tourism Ecology Capacity Based on the Nonlinear Dynamic Model

2009 ◽  
Vol 11 (2) ◽  
pp. 163-168
Author(s):  
Long LV ◽  
Zhenfang HUANG ◽  
Jiang WU
Keyword(s):  
Dynamic Model ◽  
Nonlinear Dynamic ◽  
Nonlinear Dynamic Model

scholarly journals Development, Modeling and Control of a Dual Tilt-Wing UAV in Vertical Flight

Drones ◽  
2020 ◽  
Vol 4 (4) ◽  
pp. 71
Author(s):  
Luz M. Sanchez-Rivera ◽  
Rogelio Lozano ◽  
Alfredo Arias-Montano
Keyword(s):  
Dynamic Model ◽  
Attitude Control ◽  
Test Bench ◽  
Aerodynamic Coefficients ◽  
Nonlinear Dynamic Model ◽  
Modeling And Control ◽  
Drag And Lift ◽  
And Control ◽  
Dynamics Method ◽  
Indoor And Outdoor

Hybrid Unmanned Aerial Vehicles (H-UAVs) are currently a very interesting field of research in the modern scientific community due to their ability to perform Vertical Take-Off and Landing (VTOL) and Conventional Take-Off and Landing (CTOL). This paper focuses on the Dual Tilt-wing UAV, a vehicle capable of performing both flight modes (VTOL and CTOL). The UAV complete dynamic model is obtained using the Newton–Euler formulation, which includes aerodynamic effects, as the drag and lift forces of the wings, which are a function of airstream generated by the rotors, the cruise speed, tilt-wing angle and angle of attack. The airstream velocity generated by the rotors is studied in a test bench. The projected area on the UAV wing that is affected by the airstream generated by the rotors is specified and 3D aerodynamic analysis is performed for this region. In addition, aerodynamic coefficients of the UAV in VTOL mode are calculated by using Computational Fluid Dynamics method (CFD) and are embedded into the nonlinear dynamic model. To validate the complete dynamic model, PD controllers are adopted for altitude and attitude control of the vehicle in VTOL mode, the controllers are simulated and implemented in the vehicle for indoor and outdoor flight experiments.

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