Dynamic Effects of Mandrel/Tubular Interaction on Downhole Solid Tubular Expansion in Well Engineering

2009 ◽  
Vol 131 (1) ◽  
Author(s):  
A. C. Seibi ◽  
A. Karrech ◽  
T. Pervez ◽  
S. Al-Hiddabi ◽  
A. Al-Yahmadi ◽  
...  
Keyword(s):  
Structural Response ◽  
Static Friction ◽  
Expansion Ratio ◽  
Thickness Reduction ◽  
Drawing Force ◽  
Expansion Process ◽  
Stick Slip ◽  
State Expansion ◽  
Threaded Connections ◽  
Slip Phenomenon

The expansion process subjects a solid tubular to large plastic deformations leading to variations in tubular thickness and length, which may result in premature and unexpected failures. It was noticed that the expansion process induces wall thickness imperfections due to excessive local plastic deformation as a result of mandrel sticking and slipping relative to the expanded tubular; such irregularities increase the probability of failure. Mandrel sticking may be the result of lack of enough lubrication, tubular surface irregularities, and the presence of welded and/or threaded connections, which require higher drawing force to push the mandrel forward. When the drawing force required to overcoming the maximum static friction and the mandrel forward motion is assured, the mandrel slips relative to the expanded tubular. This “stick-slip” phenomenon results in mandrel oscillations that affect the tubular response in terms of further reduction in thickness and may jeopardize the tubular capacity under normal operating field conditions. Therefore, the present work studies the mandrel dynamics and their effect on the tubular structural response. A mathematical model, which is an extension of the quasistatic tubular expansion analysis, has been developed to describe the dynamic friction effects of the stick-slip phenomenon. A special case of tubular expansion consisting of 25% expansion ratio of a 4/12 in. (114.3 mm) liner hanger was considered. It was found that the level of mandrel oscillations is in the order of 1–2 mm around its equilibrium position resulting in tubular thickness reduction of approximately 9% on top of its variation caused by the steady state expansion process. This increase in thickness reduction may affect the postexpansion collapse strength of the tubular.

Compensation of Stick-Slip Phenomenon in an Electrical Actuator

2003 ◽  
Vol 15 (4) ◽  
pp. 398-405 ◽  
Author(s):  
R. Merzouki ◽  
◽  
J. C. Cadiou ◽  
N. K. M'Sirdi
Keyword(s):  
Friction Force ◽  
Static Friction ◽  
Adaptive Controller ◽  
Nonlinear Observer ◽  
Convergence To Equilibrium ◽  
Dynamic Friction ◽  
Slip Effect ◽  
Stick Slip ◽  
Electrical Actuator ◽  
Slip Phenomenon

In mechanical systems involving low-speed motion, consisting of a succession of jumps and stops, as in trained wagons or manipulated robots, control usually exhibits error when the static friction force exceeds the dynamic friction force in what is known as the stick-slip effect. We developed a nonlinear observer to determine the friction force of contact during motion and to compensate for its effect. Simulation and experimental results show global convergence to equilibrium and good performance by the adaptive controller.

scholarly journals Experimental tests of static friction coefficient for selected material combinations of expanded graphite - steel used in sealing nodes

Mechanika ◽  
2020 ◽  
Vol 26 (2) ◽  
pp. 103-107
Author(s):  
Aleksandra Magdalena Rewolińska
Keyword(s):  
Friction Coefficient ◽  
Austenitic Steel ◽  
Significant Influence ◽  
Steel Surface ◽  
Expanded Graphite ◽  
Experimental Tests ◽  
Static Friction ◽  
Stick Slip ◽  
Static Friction Coefficient ◽  
Slip Phenomenon

The paper presents the results of static friction coefficient tests of selected material sets used in sealing nodes. Four graphite materials were tested - pure expanded graphite, expanded graphite with the addition of PTFE plastic of different densities (1.4 and 1.8 [g/cm3]) and expanded graphite laminated with austenitic steel foil - matching the steel surface. The combinations operated in a reciprocal movement. The measurements were made at different unit pressures (0.5, 2 and 5 MPa) and for different work cycles (0, 500, 1500 and 3000). On the basis of the results obtained, it was found that both the load and the number of work cycles have a significant influence on the value of the static friction coefficient of the tested materials. Not without significance is also the density of selected graphite materials. It was found that expanded graphite with PTFE and density of 1.8 g/cm3 was characterized by the lowest static friction coefficient in comparison with other materials. It is also worth noting the fact of a layer on the steel surface of combination which promotes the formation of stick-slip phenomenon.

Preliminary Study on Stick-Slip in Drillstring With Analytical Model Expressed With Neutral Delay Differential Equation

2014 ◽  
Author(s):  
Tomoya Inoue ◽  
Tokihiro Katsui ◽  
Chang-Kyu Rheem ◽  
Zengo Yoshida ◽  
Miki Y. Matsuo
Keyword(s):  
Differential Equation ◽  
Analytical Model ◽  
Delay Differential Equation ◽  
Drill Bit ◽  
Neutral Delay ◽  
Stick Slip ◽  
Scientific Drilling ◽  
Neutral Delay Differential Equation ◽  
Delay Differential ◽  
Slip Phenomenon

Stick-slip is a major problem in offshore drilling because it may cause damage to the drill bit as well as crushing or grinding the sediment layer, which is crucial problem in scientific drilling because the purpose of the scientific drilling is to recover core samples from the layers. To mitigate stick-slip, first of all it is necessary to establish a model of the torsional motion of the drill bit and express the stick-slip phenomenon. Toward this end, the present study proposes a model of torsional waves propagating in a drillstring. An analytical model is developed and used to derive a neutral delay differential equation (NDDE), a special type of equation that requires time history, and an analytical model of stick-slip is derived for friction models between the drill bit and the layer as well as the rotation speed applied to the uppermost part of the drill string. In this study, the stick-slip model is numerically analyzed for several conditions and a time series of the bit motions is obtained. Based on the analytical results, the appearance of stick-slip and its severity are discussed. A small-scale model experiment was conducted in a water tank to observe the stick-slip phenomenon, and the result is discussed with numerical analysis. In addition, utilizing surface drilling data acquired from the actual drilling operations of the scientific drillship Chikyu, occurrence of stick-slip phenomenon is discussed.

Effect of laser-textured micro dimples on inhibition of stick-slip phenomenon of sliding guideway

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yonghong Fu ◽  
Jie Yang ◽  
Hao Wang ◽  
Yuyang He
Keyword(s):  
Hydrodynamic Lubrication ◽  
Textured Surface ◽  
Stick Slip ◽  
Content Type ◽  
Speed Range ◽  
Lubrication Condition ◽  
Micro Dimples ◽  
Pin On Disk ◽  
Micro Dimple ◽  
Slip Phenomenon

Purpose This study aims to investigate the efficacy of micro dimple in inhibiting stick-slip phenomenon on the sliding guideway. Design/methodology/approach In this study, micro-dimples were fabricated by laser on surfaces of steel disk and guideway. The disks and guideways were respectively performed pin-on-disk tribological tests and working condition experiments to study differences in lubrication condition and friction stability between textured and untextured surfaces. Findings Micro-dimples help reduce critical sliding speed that allows contact surfaces to enter in hydrodynamic lubrication regime. This increases hydrodynamic lubrication range and narrows speed range where stick-slip phenomenon can occur, enhancing sliding guideway’s adaptability for broader working conditions. Furthermore, friction stability on the textured surface improved, lowering the occurrence possibility of stick-slip phenomenon. Finally, difference between static and kinetic frictions on the textured surface is lower relative to the untextured surface, which decreases the critical velocity when the stick-slip phenomenon occurs. Originality/value The results indicate that laser-textured micro-dimples are significantly conducive to inhibit stick-slip phenomenon, thus providing smoother movement for the guideway and eventually increasing precision of the machine.

Static Friction Models for Vehicle Simulation Study

2006 ◽  
Author(s):  
Xubin Song ◽  
Daniel G. Smedley
Keyword(s):  
Simulation Study ◽  
Static Friction ◽  
Friction Modeling ◽  
Stick Slip ◽  
Vehicle Simulation ◽  
Engineering Software ◽  
Variable Step ◽  
History Of ◽  
Friction Models ◽  
Smooth Dynamics

The history of the challenge of friction modeling is briefly reviewed. Then this paper focuses on the modeling and simulation study of the friction related dynamics in the Simulink® environment, because Matlab®/Simulink® are popular engineering software tools for both industry and academia. Matlab® and Simulink® are the proprietary products of MathWorks, Inc. In this paper, the static friction models are studied through Simulink® by applying fixed and variable step sizes. The comparison shows that the static Karnopp model is not only numerically tractable but also can be inclusive of the fundamental friction characteristics of both stick slip and correct friction predictions. Finally this paper presents an improved Karnopp model for clutch modeling with the use of Simulink®, and the simulation shows that this model is computationally tractable with smooth dynamics.

Stick-Slip Compensation of Micro-Positioning Using Elastic-Plastic Static Friction Model

2008 ◽  
Vol 47-50 ◽  
pp. 246-249
Author(s):  
Min Gyu Jang ◽  
Chul Hee Lee ◽  
Seung Bok Choi
Keyword(s):  
Static Friction ◽  
Friction Model ◽  
Smart Structure ◽  
Asperity Contact ◽  
Stick Slip ◽  
Elastic Plastic ◽  
Highly Nonlinear ◽  
Bridge Type ◽  
Structural Parts ◽  
Rough Surface Contact

In this paper, a stick-slip compensation for the micro-positioning is presented using the statistical rough surface contact model. As for the micro-positioning structure, PZT (lead(Pb) zirconia(Zr) Titanate(Ti)) actuator is used to drive the load for precise positioning with its high resolution incorporating with the PID (Proportional Integral Derivative) control algorithm. Since the stick-slip characteristics for the micro structures are highly nonlinear and complicated, it is necessary to incorporate more detailed stick-slip model for the applications involving the high precision motion control. Thus, the elastic-plastic static friction model is used for the stick-slip compensation considering the elastic-plastic asperity contact in the rough surfaces statistically. Mathematical model of the system for the positioning apparatus was derived from the dynamic behaviors of structural parts. Since the conventional piezoelectric actuator generates the short stroke, a bridge-type flexural hinge mechanism is introduced to amplify the linear motion range. Using the proposed smart structure, simulations under the representative positioning motion were conducted to demonstrate the micro-positioning under the stick-slip friction.

Optimum Mandrel Configuration for Efficient Down-Hole Tube Expansion

2012 ◽  
Author(s):  
Tasneem Pervez ◽  
Omar S. Al-Abri ◽  
Sayyad Z. Qamar ◽  
Asiya M. Al-Busaidi
Keyword(s):  
Cross Section ◽  
Oil And Gas ◽  
Cone Angle ◽  
Circular Cross Section ◽  
Element Model ◽  
Expansion Ratio ◽  
Dissipated Energy ◽  
Drawing Force ◽  
Enhanced Production ◽  
Tube Expansion

In the last decade, traditional tube expansion process has found an innovative application in oil and gas well drilling and remediation. The ultimate goal is to replace the conventional telescopic wells to mono-diameter wells with minimum cost, which is still a distant reality. Further to this, large diameters are needed at terminal depths for enhanced production from a single well while keeping the power required for expansion and related costs to a minimum. Progress has been made to realize slim wells by driving a rigid mandrel of a suitable diameter through the tube either mechanically or hydraulically to attain a desirable expansion ratio. This paper presents a finite element model which predicts the drawing force for expansion, the stress field in expanded and pre/post expanded zones, and the energy required for expansion. Through minimization of energy required for expansion, an optimum mandrel configuration i.e. shape, size and angle was obtained which can be used to achieve larger in-situ expansion. It is found that mandrel with elliptical, hemispherical and curved conical shapes have minimum resistance during expansion as compared to the widely used circular cross section mandrel with a cone angle of 10°. However, further manipulation of shape parameters of the circular cross section mandrel revealed an improved efficiency. The drawing force required for expansion reduces by 7% to 10% having minimum dissipated energy during expansion. It is also found that these cones yield less reduction in tube thickness after expansion, which results in higher post-expansion collapse strength. In addition, rotating a mandrel further reduces the energy required for expansion by 7%.

scholarly journals FRICTION ANALYSIS IN CASE OF THE CARRIAGE- FEED SHAFT CINEMATIC COUPLING AT CNC LATHE

2020 ◽  
Vol 7 (5) ◽  
pp. 30-37
Author(s):  
Daniel Popescu
Keyword(s):  
Mathematical Model ◽  
Rational Design ◽  
Normal Force ◽  
Stick Slip ◽  
Disturbing Force ◽  
Dimensional Precision ◽  
Cnc Lathe ◽  
Elastic Systems ◽  
Friction Analysis ◽  
Slip Phenomenon

The paper presents a mathematical model for analysis of friction between the tool bearing saddle and conductor at CNC lathe. The analysis of longitudinal advance movement laws is performed taking into account the appearance and development of disturbing harmonic forces created by auto-vibrations determined by the interaction between the partial elastic systems of tool and workpiece. The friction force is emphasized as product of two components depending on the sliding speed and on the normal disturbing force. By establishing the dynamic response of the system, when the normal force depends linearly on speed, acceleration and mobile ensemble position, the premises are created for stability analysis of the friction movement, obtaining the limit speeds under which the stick-slip phenomenon occurs. Thus, it is provided for a rational design of CNC lathe elastic structure, in order to improve the surface quality and the dimensional precision.

scholarly journals Development of Artificial Skin Using Keratin Film for Evaluation of Puncture Performance of Microneedle

2020 ◽  
Vol 32 (2) ◽  
pp. 351-361
Author(s):  
Ryo Nishino ◽  
Seiji Aoyagi ◽  
Masato Suzuki ◽  
Atsushi Ueda ◽  
Yuki Okumura ◽  
...  
Keyword(s):  
Stratum Corneum ◽  
Human Skin ◽  
Human Hair ◽  
Subcutaneous Tissue ◽  
Artificial Skin ◽  
Resistance Force ◽  
Stick Slip ◽  
Silicon Rubber ◽  
Animal Skin ◽  
Slip Phenomenon

Humans do not feel pain when bitten by mosquitos; therefore, we have attempted to develop a microneedle that mimics the puncturing mechanism of mosquitos. We have quantitatively evaluated the puncturing performance of the developed microneedle by puncturing an artificial skin made from polydimethylsiloxane (PDMS), a kind of silicon rubber. Unlike the mono-layered PDMS, however, animal skin including human skin is structured to have a hard stratum corneum, epidermis and dermis over soft subcutaneous tissue. In this paper, we propose an artificial skin having a two-layered hard/soft structure, constructed from PDMS with a human-hair-derived keratin film adhered onto the top surface. We evaluated the hardness of the keratin film (Young’s modulus) and found that it could qualitatively simulate the hard layers of the skin including the stratum corneum. The artificial skin we developed reproduced the following phenomena: the decrease in resistance force of animal skin at the point when the needle penetrates the surface followed by variation in resistance due to the stick-slip phenomenon as the needle penetrates more deeply.

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