Effect of Tool Joints on Passages of Plane Longitudinal and Torsional Waves Along a Drill Pipe

1963 ◽  
Vol 85 (2) ◽  
pp. 156-162 ◽  
Author(s):  
R. E. Bradbury ◽  
J. C. Wilhoit
Keyword(s):  
Approximate Solution ◽  
Equations Of Motion ◽  
Drill Pipe ◽  
Drill String ◽  
Negligible Effect ◽  
Governing Equations ◽  
Torsional Waves ◽  
Tool Joint

The effect of tool joints on the passage of plane longitudinal and torsional waves along a drill pipe was studied. An approximate solution to the governing equations of motion was found, and an idealized tool joint constructed. Calculations were made for the effect of the idealized joint on an example drill string. The results showed that tool joints had negligible effect for exciting frequencies of the same order as common rotary speeds and the drill pipe could be taken as a uniform pipe with negligible error.

Rotating Control Device Sealing Element Customization for Ultra-Deepwater Gulf of Mexico

2021 ◽  
Author(s):  
Blaine Dow ◽  
Dexter Pazziuagan ◽  
Ken Vaczi ◽  
Chima Chima ◽  
Jason Guidry ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Drill Pipe ◽  
Cost Effective ◽  
Control Device ◽  
Drill String ◽  
Lessons Learned ◽  
Test Procedures ◽  
Element Analysis ◽  
Effective Manner ◽  
Tool Joint

Abstract As the Managed Pressure Drilling (MPD) systems for deepwater drilling rigs mature, operators are applying the technology on more complex prospects. Wells are encountering higher pressures in deeper water depths, pushing against the boundaries of technical limits not previously encountered. A prospect in the US Gulf of Mexico required drilling to measured depths exceeding 31000 feet in water deepwater. Under such demanding depth, a non-typical drillstring was required to manage the tensile loading. Typical drill pipe connections on 6 5/8" S-135 tool joints are 8.5" diameter. This drill string would require V-150 landing string, with a 6 5/8" FH tool joint diameter of 8.875". Hard banding would bring the tool joint nominal OD above 9". The depth of the well and planned string RPM presented risk of casing wear, therefore drillpipe protectors would also be required. The depth of the reservoir and size of the drillstring meant pipe would need to be stripped out of the well with up to 900 psi backpressure in order to maintain constant bottom hole pressure. All well challenges were used to determine design specifications for a custom sealing element. The scope of work was to design, validate through finite element analysis, then validate in a test fixture per API16RCD test procedures. On conclusion of the product validation, a land test rig trial, with mock-up of the planned system, including dual sealing elements in the Rotating Control Device (RCD), the required non-rotating drill pipe protectors on the planned drillpipe, was executed. The development schedule from start to finish was compressed to less than 6 months also, targeting completion ahead of the rig's drilling program. This paper will recount the various phases of the design-build-validate-test effort that went into resolving these technical limits. It will conclude with field results and lessons learned from first deployment. As operators pursue more challenging deepwater wells, this systematic approach, through alignment of the operator, drilling contractor and MPD technology company, serves as a model to expand the operating envelope of drilling systems, improving safe performance in a cost-effective manner.

Modeling and Experimental Investigations of Drill Pipe Failure

2017 ◽  
Author(s):  
Jamil Abdo ◽  
Edris M. Hassan ◽  
Khaled Boulbrachene ◽  
Jan Kwak
Keyword(s):  
Fatigue Failure ◽  
Torsional Vibration ◽  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
Drill Pipe ◽  
Drill String ◽  
Experimental Investigations ◽  
Vibration Modes ◽  
Pipe Failure ◽  
Coupling Equations

During drilling operations, drill string interacts continuously with rock formation, which result in severe shock and vibrations. Lateral, torsion and axial vibration modes often cause failures of Bottom Hole Assembly (BHA), drill pipe abrasive wear, drill bit and wall borehole damages. It also leads to reduction in Rate of Penetration (ROP) and consequently incur unnecessarily high costs. The Lagrangian approach has been used in this study to attain drill pipe lateral and torsional vibration coupling equations of motion. The mathematical model is expressed in terms of four independent degrees of freedom. The effects of bending and torsion vibrations, and whirling motion of the drill string are incorporated in the developed model. A set of nonlinear equations are solved numerically to obtain the response of the system. In this work, we also present a brief description of an in-house constructed experimental setup. The setup has the capability to imitate the downhole axial, lateral and torsional vibration modes and mechanisms. Experimental investigations for the drill pipe fatigue failure due to lateral and torsional cyclic stresses induced in the drill string are also presented. Such investigations are essential for oil/gas industry as they provide solutions for very common problems such as drill string fatigue failure. The performance of the setup was validated. Numbers of tests were performed to investigate the effects of rotational speeds on the vibration amplitudes of different drill string sizes.

The Dynamics of an Imperfect, Multigimbal, Hooke's-Joint Gyroscope

1978 ◽  
Vol 20 (5) ◽  
pp. 263-269 ◽  
Author(s):  
J. S. Burdess ◽  
C. H. J. Fox
Keyword(s):  
Approximate Solution ◽  
Dynamic Stability ◽  
Angular Displacement ◽  
Equations Of Motion ◽  
Governing Equations ◽  
Hooke’S Joint

The paper examines the effect of damping and mistuning on the performance of a dynamically-tuned, multigimbal, Hooke's-joint gyroscope. The dynamic stability of the gyro is considered and rotor damping is shown to be a source of instability at rotor speeds in excess of the tuning speed. Using an approximate solution to the governing equations of motion, it is shown that the instrument's capacity to measure either rate of turn or total angular displacement is limited by the degree of mistuning and the damping conditions. The response of the tuned instrument to harmonic inputs at twice rotor frequency is examined and the conditions for a 2ω drift-free gyro are derived.

Simulation of Engine Vibration on Nonlinear Hydraulic Engine Mounts

2005 ◽  
Author(s):  
A. R. Ohadi ◽  
G. Maghsoodi
Keyword(s):  
Equations Of Motion ◽  
Low Frequency ◽  
Governing Equations ◽  
Engine Mounts ◽  
Engine Vibration ◽  
Engine Mount ◽  
Rotational Motions ◽  
The Time Domain ◽  
Nonlinear Equations Of Motion ◽  
Four Cylinders

In this paper, vibration behavior of engine on nonlinear hydraulic engine mount including inertia track and decoupler is studied. In this regard, after introducing the nonlinear factors of this mount (i.e. inertia and decoupler resistances in turbulent region), the vibration governing equations of engine on one hydraulic engine mount are solved and the effect of nonlinearity is investigated. In order to have a comparison between rubber and hydraulic engine mounts, a 6 degree of freedom four cylinders V-shaped engine under inertia and balancing masses forces and torques is considered. By solving the time domain nonlinear equations of motion of engine on three inclined mounts, translational and rotational motions of engines body are obtained for different engine speeds. Transmitted base forces are also determined for both types of engine mount. Comparison of rubber and hydraulic mounts indicates the efficiency of hydraulic one in low frequency region.

Reduction of Noise Inside a Cavity by Piezoelectric Actuators

2003 ◽  
Vol 125 (1) ◽  
pp. 12-17 ◽  
Author(s):  
I. Hagiwara ◽  
D. W. Wang ◽  
Q. Z. Shi ◽  
R. S. Rao
Keyword(s):  
Sound Pressure ◽  
Control Mechanism ◽  
Equations Of Motion ◽  
Piezoelectric Actuators ◽  
Governing Equations ◽  
Control Laws ◽  
Modal Coupling ◽  
Modal Amplitude ◽  
Global And Local ◽  
Fully Coupled

A new analytical model is developed for the reduction of noise inside a cavity using distributed piezoelectric actuators. A modal coupling method is used to establish the governing equations of motion of the fully coupled acoustics-structure-piezoelectric patch system. Two performance functions relating “global” and “local” optimal control of sound pressure levels (SPL) respectively are applied to obtain the control laws. The discussions on associated control mechanism show that both the mechanisms of modal amplitude suppression and modal rearrangement may sometimes coexist in the implementation of optimal noise control.

Pipe stick problems of deep well drilling

2021 ◽  
Vol 66 (05) ◽  
pp. 192-195
Author(s):  
Rövşən Azər oğlu İsmayılov ◽  
Keyword(s):  
Drilling Fluid ◽  
Drill Pipe ◽  
Drill String ◽  
Differential Pressure ◽  
Drilling Mud ◽  
Fluid Circulation ◽  
Well Drilling ◽  
Deep Well ◽  
Pressure Pipe ◽  
Bottomhole Pressure

The aricle is about the pipe stick problems of deep well drilling. Pipe stick problem is one of the drilling problems. There are two types of pipe stick problems exist. One of them is differential pressure pipe sticking. Another one of them is mechanical pipe sticking. There are a lot of reasons for pipe stick problems. Indigators of differential pressure sticking are increase in torque and drug forces, inability to reciprocate drill string and uninterrupted drilling fluid circulation. Key words: pipe stick, mecanical pipe stick,difference of pressure, drill pipe, drilling mud, bottomhole pressure, formation pressure

Influence of Material Damping on In-Plane Modal Parameters for Rotating Disks

2012 ◽  
Author(s):  
Hamid R. Hamidzadeh ◽  
Ehsan Sarfaraz
Keyword(s):  
Elastic Moduli ◽  
Damping Ratio ◽  
Equations Of Motion ◽  
Elastic Stability ◽  
Rotating Disks ◽  
Governing Equations ◽  
Annular Disk ◽  
Stress Theory ◽  
Hysteretic Damping ◽  
Circumferential Wave

The linear in-plane free vibration of a thin, homogeneous, viscoelastic, rotating annular disk is investigated. In the development of an analytical solution, two dimensional elastodynamic theory is employed and the viscoelastic material for the medium is allowed by assuming complex elastic moduli. The general governing equations of motion are derived by implementing plane stress theory. Natural frequencies are computed for several modes at specific radius ratios with fixed-free boundary conditions and modal loss factors for different damping ratios are determined. The computed results were compared to previously established results. It was observed that the effects of rotational speed and hysteretic damping ratio on natural frequency and elastic stability of the rotating disks were related to the mode of vibration and type of circumferential wave occurring.

scholarly journals Conducting dusty fluid flow through a constriction in a porous medium

2016 ◽  
Vol 5 (1) ◽  
pp. 29
Author(s):  
Madhura K R ◽  
Uma M S
Keyword(s):  
Porous Medium ◽  
Hartmann Number ◽  
Equations Of Motion ◽  
Fluid Phase ◽  
Dust Particles ◽  
Governing Equations ◽  
Electrically Conducting ◽  
Electrically Conducting Fluid ◽  
Flow Through ◽  
Constricted Channel

<p><span lang="EN-IN">The flow of an unsteady incompressible electrically conducting fluid with uniform distribution of dust particles in a constricted channel has been studied. The medium is assumed to be porous in nature. The governing equations of motion are treated analytically and the expressions are obtained by using variable separable and Laplace transform techniques. The influence of the dust particles on the velocity distributions of the fluid are investigated for various cases and the results are illustrated by varying parameters like Hartmann number, deposition thickness on the walls of the cylinder and the permeability of the porous medium on the velocity of dust and fluid phase.</span></p>

scholarly journals Vibration Characteristics of Piezoelectric Microbeams Based on the Modified Couple Stress Theory

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
R. Ansari ◽  
M. A. Ashrafi ◽  
S. Hosseinzadeh
Keyword(s):  
Boundary Conditions ◽  
Couple Stress ◽  
Natural Frequencies ◽  
Couple Stress Theory ◽  
Equations Of Motion ◽  
Modified Couple Stress Theory ◽  
Beam Model ◽  
Governing Equations ◽  
Stress Theory ◽  
Modified Couple Stress

The vibration behavior of piezoelectric microbeams is studied on the basis of the modified couple stress theory. The governing equations of motion and boundary conditions for the Euler-Bernoulli and Timoshenko beam models are derived using Hamilton’s principle. By the exact solution of the governing equations, an expression for natural frequencies of microbeams with simply supported boundary conditions is obtained. Numerical results for both beam models are presented and the effects of piezoelectricity and length scale parameter are illustrated. It is found that the influences of piezoelectricity and size effects are more prominent when the length of microbeams decreases. A comparison between two beam models also reveals that the Euler-Bernoulli beam model tends to overestimate the natural frequencies of microbeams as compared to its Timoshenko counterpart.

scholarly journals Vibration and Instability of Rotating Composite Thin-Walled Shafts with Internal Damping

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Ren Yongsheng ◽  
Zhang Xingqi ◽  
Liu Yanghang ◽  
Chen Xiulong
Keyword(s):  
Virtual Work ◽  
Numerical Study ◽  
Equations Of Motion ◽  
Beam Theory ◽  
Dynamical Analysis ◽  
Design Parameters ◽  
Internal Damping ◽  
Analysis Method ◽  
Governing Equations ◽  
Thin Walled

The dynamical analysis of a rotating thin-walled composite shaft with internal damping is carried out analytically. The equations of motion are derived using the thin-walled composite beam theory and the principle of virtual work. The internal damping of shafts is introduced by adopting the multiscale damping analysis method. Galerkin’s method is used to discretize and solve the governing equations. Numerical study shows the effect of design parameters on the natural frequencies, critical rotating speeds, and instability thresholds of shafts.

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