Finite Element Formulation for Prediction and Quantification of Stick-Slip Phenomenon in Down-Hole Tubular Expansion

Author(s):  
Omar S. Al-Abri ◽  
Tasneem Pervez ◽  
Sayyad Z. Qamar ◽  
Rashid Khan

The challenges in exploration and development of unconventional oil and gas resources are enormous. The complex reservoir characteristics, and oil and gas flow regimes introduce difficulty in predicting the oil and gas in-place, recovery and production profiles, and wells placement, design and completion. Horizontal drilling and completion using centuries-old manufacturing process of tube forming resulted in producing oil and gas from large areas with smaller footprint on the surface. Though expensive but it optimizes the recovery. The in-situ diametral expansion of tubular using a solid mandrel causes permanent deformation in which the system experiences large frictional forces at mandrel/tubular interface resulting in stick-slip phenomenon. It results in varying tubular thickness and diametral eccentricity which causes structural instability in wells leading to premature failure. A finite element model describing the dynamics of stick-slip phenomenon in down-hole tubular expansion was developed. Three different set of equations; one each for stick, slip and transition phases were derived using equilibrium equations, time-dependent static friction model and velocity-dependent kinetic friction model. A switch model utilizing the zero velocity interval criterion was used to define stick, slip and transition phases. The newly developed model was implemented in the finite element model by means of two user-defined subroutines namely VFRIC and VDLOAD in commercial finite element software ABAQUS. Experimental and simulation results agree well for expansion force, wall thickness reduction and tubular length shortening. It was found that the thickness variation is the most critical parameter due to its effect in lowering collapse strength of expanded tubular. Parametric study investigations showed that the effect of this phenomenon may possibly be minimized by manipulating mandrel geometry, contact conditions, and/or mandrel speed.

2013 ◽  
Vol 663 ◽  
pp. 580-585
Author(s):  
Zhi Tao Tang ◽  
Tao Yu ◽  
Li Qiang Xu

Based on finite element software DEFORM-3D, a three-dimensional oblique cutting model for aerospace aluminum alloy was built. The material’s flow stress behavior was described with Johnson-Cook constitutive equation. The separation of the chips with the workpiece was realized by the combination of adaptive remeshing technique and separation criterion. The material’s failure was defined by adopting Cockcroft & Latham fracture criterion. The tool-chip friction model was the combination of a Coulomb friction model and shear (sticking) friction model. To validate the finite element model, cutting tests were conducted. The effects of tool geometrical parameters such as flank wear, cutting edge inclination and corner radius on cutting forces were analyzed by three-dimensional oblique finite element model.


2012 ◽  
Vol 443-444 ◽  
pp. 751-756
Author(s):  
Li Jun Suo ◽  
Xia Guang Hu

In China, it is fact that porous concrete base has been used in the construction of asphalt pavement in recent years because porous concrete base has good performance. However, Reasonable design method has not been put forward so far. Therefore, it is necessary to analyze load stress and thermal stress of asphalt pavement which includes porous concrete base in order to put forward theoretical basis for pavement design method. In the paper, three–dimension finite element model of asphalt pavement, which includes porous concrete base and asphalt surface, is created for the purpose of studying load stress and thermal stress of porous concrete base in asphalt pavement. Based on numerical method of three–dimension finite element model, finite element software, such as ANSYS, is employed to study load stress and thermal stress of porous concrete base in asphalt pavement. After that, the effect of different factors on stress is studied, and the factors include thickness of surface, thickness of base and ratio of base’s modulus to foundation’s modulus. Finally, calculation results for stress are compared with each other, and it shows that load stress of porous concrete base decreases with increase of base’s thickness, while thermal stress of porous concrete base increases with increase of base’s thickness. Load stress and thermal stress of porous concrete base decrease with increase of surface’s thickness. Load stress and thermal stress of porous concrete base increase with increase of ratio of base’s modulus to foundation’s modulus.


2012 ◽  
Vol 479-481 ◽  
pp. 457-461
Author(s):  
Dong Hui Chen ◽  
Xin Lu ◽  
Xing Wang Chai ◽  
Bao Gang Wang ◽  
Hong Xia Guo ◽  
...  

In this paper,soil parameters and the collected data were tested and processed, and the changing trends of force with drilling depth were obtained and the maximum force applying to the working components was picked up. Compared with the smooth working component, the force applying to the unsmooth working components is smaller. Some parameters needed in Drucker-Prager soil model were measured and modified according to the basic tests. The simulation model was built in the finite element software -ANSYS. The simulation result is consistent with the actual testing result, which confirms the finite element model is correct .


2010 ◽  
Vol 456 ◽  
pp. 103-114
Author(s):  
Shi Ling Xing ◽  
Jian Shu Ye ◽  
Hang Sun

In order to use finite element software to complete the design or calculation of bridge multi-pile foundation, this paper discusses the finite element model (FEM) of a bridge multi-pile based on the theory and provisions in Code for Design of Ground Base and Foundation of Highway Bridges and Culverts (CDGBFHBC 2007) of china. For the FEM of a bridge-multi pile foundation, cap is regarded as a rigid body, piles are taken as beams, and boundary constraints are a series of horizontal springs and vertical springs. First, the formula of stiffness for horizontal springs and bottom vertical spring is derived according to elastic ground base theory and winkler hypotheses. Secondly, for the friction pile, the stiffness of vertical springs on piles side is derived basis of the principle of friction generated and simplified distribution of pile shaft resistance. Then, the FEM of multi-pile needs pay attention to three issues: the simulation of connections between piles and cap, elastic modulus needs discount, and the weight for pile underneath the ground line (or local scour line) needs calculate by half. Taking pile section bending moment often control the design and calculation of pile into account, this paper gives a simplified FEM of pile. Finally, an example is used to introduce the application of the FEM of bridge multi-pile foundation.


Author(s):  
Jiefeng Jiang ◽  
Yunbo Bi ◽  
Huiyue Dong ◽  
Yinglin Ke ◽  
Xintian Fan ◽  
...  

The interference fit can improve the fatigue performance of mechanical joints and is widely used in aircraft assembly. In this paper, specimens of lap plates and several interference fit sizes were designed, and then the interference fit hi-lock bolt insertion was carried out in an experimental test. Using the commercial finite element software ABAQUS, a two-dimensional axisymmetric finite element model was established to simulate the bolt insertion process. The finite element model was validated by comparison of experimental results and finite element prediction for insertion force and protuberance height. After the interference fitted bolt insertion, the changing characteristics of the non-uniform hole expansion and protuberance were presented with increases in interference fit size. Under low level of interference fit, the tensile hoop stress was produced mainly on the hole wall, and changed into compressive hoop stress when interference fit size is larger. The maximum tensile hoop stress point on faying surfaces went away from the hole wall with interference fit size increasing.


2012 ◽  
Vol 487 ◽  
pp. 879-883
Author(s):  
Jiang Wei Wu

With the port crane getting bigger and heavier, and also moving much faster than before, the thermal effect in wheel and rail during the brake process can be a reason of the failure of port crane. In this paper, the thermal effect during the brake process of port crane is studied using the finite element method. Based on the finite element model, the ANSYS10.0 finite element software is used. The thermal effects under different coefficients are discussed. Three different slide speed of wheel, two different loads of crane, and three different frictional coefficients are applied. The importance of the different coefficients is obtained from the numerical results.


2012 ◽  
Vol 488-489 ◽  
pp. 753-758 ◽  
Author(s):  
P. Ganesh ◽  
V.S. Senthil Kumar

The friction stir welded superplastic forming of AA6061-T6 sheet has been numerically analyzed based on the experimental and finite element software. A selected range of tool rotating speeds of 500, 1000 and 2000 rpm was used for friction stir welding. At constant temperature of 550O C and constant pressure of 0.4 Mpa, superplastic forming experiments was performed using free forming die for the friction stir welded sheets. A detailed 3D element type study has been performed in the finite element analysis. The proposed finite element model has been validated in comparison with experimental data. The results are found to have reasonably good agreement between simulations and experiment. The effect of constant pressure, coefficient of friction, strainrate and strain-rate sensitivity has been studied using the proposed finite element model.


2012 ◽  
Vol 151 ◽  
pp. 484-489 ◽  
Author(s):  
Jie Fang Xing ◽  
Jie Zhang ◽  
Lu Jun He

Introduce some basic knowledge, methods and theory of using the finite element software ANSYS to carry out contact analysis, and then establish the contact simulation analysis finite element model for CTP imaging drum and plate by using the software ANSYS. A numerical simulation analysis on the imaging drum and the plate indicates that the analysis results are consistent with the experimental results, so as to lay the foundation for the reliability and stability of dynamic design and optimization design of CTP imaging drum.


Author(s):  
Dongxu Li ◽  
Brian Uy ◽  
Farhad Aslani ◽  
Chao Hou

Spiral welded stainless tubes are produced by helical welding of a continuous strip of stainless steel. Recently, concrete-filled spiral welded stainless steel tubes have found increasing application in the construction industry due to their ease of fabrication and aesthetic appeal. However, an in-depth understanding of the behaviour of this type of structure is still needed due to the lack of proper design guidance and insufficient experimental verification. In this paper, the mechanical performance of concrete-filled spiral welded stainless steel tubes will be numerically investigated with a commercial finite element software package, through which an experimental program can be designed properly. Specifically, the proposed finite element models take into account the effects of material and geometric nonlinearities. Moreover, the initial imperfections of stainless steel tubes and the form of helical welding will be appropriately included. Enhancement of the understanding of the analysis results can be achieved by extending results through a series of parametric studies based on the developed finite element model. Thus, the effects of various design parameters will be further evaluated by using the developed finite element model. Furthermore, for the purposes of wide application of such types of structure, the accuracy of the behaviour prediction in terms of ultimate strength based on current design codes will be studied. The authors herein compared the load capacity between the finite element analysis results and the existing codes of practice.


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