The Analysis of Horizontal Extension Capability in Horizontal Wells

2014 ◽  
Vol 1010-1012 ◽  
pp. 1745-1749
Author(s):  
Wei Kai Liu ◽  
Ming Xing Song ◽  
Zi Yi Xu ◽  
Xue Hong Zhang
Keyword(s):  
Drag Force ◽  
Field Data ◽  
Horizontal Wells ◽  
Element Model ◽  
Force Analysis ◽  
Gap Element ◽  
Field Works ◽  
Set Up

It is critical to understand whether the available drilling assembly could meet the requirements of drilling design during the design and drilling of horizontal wells. This paper pointed out several limitations on horizontal extension capability of horizontal wells and provided judging criteria of the limit of horizontal extension based upon the characteristics of horizontal wells, and set up the gap element model analyzing torque and dragged of whole drill strings in horizontal wells. According to the force analysis of drill strings in bores given the foundation for regularities in the distribution of torque and drag force along the axis, on the basis of those above mentioned models and theories, a software was made to calculate the torque and drag force of a well, which compared with the field data, the average discrepancies of theoretical values are below 20% that could meet the needs in field works.

scholarly journals Skyline Tensile Forces in Cable Logging

2021 ◽  
Vol 42 (2) ◽  
Author(s):  
Omar Mologni ◽  
Luca Marchi ◽  
Kevin C. Lyons ◽  
Stefano Grigolato ◽  
Raffaele Cavalli ◽  
...  
Keyword(s):  
Finite Element ◽  
Field Data ◽  
Physical Simulation ◽  
Element Model ◽  
Cable Line ◽  
Tensile Forces ◽  
Cable Logging ◽  
Set Up ◽  
Cable Lines ◽  
Actual Response

Skyline tensile forces have been shown to frequently exceed the recommended safety limits during ordinary cable logging operations. Several models for skyline engineering analyses have been proposed. Although skyline tensile forces assume a dynamic behaviour, practical solutions are based on a static approach without consideration of the dynamic nature of the cable systems.The aim of this study was to compare field data of skyline tensile forces with the static calculations derived by dedicated available software such as SkylineXL. To overcome the limitation of static calculation, this work also aimed to simulate the actual response of the tensile fluctuations measured in the real environment by mean of a finite element model (FEM).Field observations of skyline tensile forces included 103 work cycles, recorded over four different cable lines in standing skyline configuration. Payload estimations, carriages positions, and time study of the logging operations were also collected in the field. The ground profiles and the cable line geometries were analysed using digital elevation models. The field data were then used to simulate the work cycles in SkylineXL. The dynamic response of six fully-suspended loads in a single-span cable line was also simulated by a dedicated FEM built through ANSYS®. The observed data and the software calculations were then compared.SkylineXL resulted particularly reliable in the prediction of the actual tensile forces, with RMSE ranging between 7.5 and 13.5 KN, linked to an average CV(RMSE) of 7.24%. The reliability in predicting the peak tensile forces was lower, reporting CV(RMSE) of 10.12%, but still not likely resulting in a safety or performance problem. If properly set-up and used, thus, SkylineXL could be considered appropriate for operational and practical purposes. This work, however, showed that finite element models could be successfully used for detailed analysis and simulation of the skyline tensile forces, including the dynamic oscillations due to the motion of the carriage and payload along the cable line. Further developments of this technique could also lead to the physical simulation and analysis of the log-to-ground interaction and the investigation of the breakout force during lateral skidding.

scholarly journals Vibration characteristics of triple-gear-rotor system in compressed air energy storage under variable torque load

2021 ◽  
Vol 104 (1) ◽  
pp. 003685042098705
Author(s):  
Xinran Wang ◽  
Yangli Zhu ◽  
Wen Li ◽  
Dongxu Hu ◽  
Xuehui Zhang ◽  
...  
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Element Model ◽  
Rotor System ◽  
Dynamic Responses ◽  
System Response ◽  
Rotating Speed ◽  
Torque Load ◽  
Set Up ◽  
Two Stages

This paper focuses on the effects of the off-design operation of CAES on the dynamic characteristics of the triple-gear-rotor system. A finite element model of the system is set up with unbalanced excitations, torque load excitations, and backlash which lead to variations of tooth contact status. An experiment is carried out to verify the accuracy of the mathematical model. The results show that when the system is subjected to large-scale torque load lifting at a high rotating speed, it has two stages of relatively strong periodicity when the torque load is light, and of chaotic when the torque load is heavy, with the transition between the two states being relatively quick and violent. The analysis of the three-dimensional acceleration spectrum and the meshing force shows that the variation in the meshing state and the fluctuation of the meshing force is the basic reasons for the variation in the system response with the torque load. In addition, the three rotors in the triple-gear-rotor system studied show a strong similarity in the meshing states and meshing force fluctuations, which result in the similarity in the dynamic responses of the three rotors.

scholarly journals Corrosion of Steel Rebars in Anoxic Environments. Part II: Pit Growth Rate and Mechanical Strength

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2547
Author(s):  
Elena Garcia ◽  
Julio Torres ◽  
Nuria Rebolledo ◽  
Raul Arrabal ◽  
Javier Sanchez
Keyword(s):  
Mechanical Strength ◽  
Chloride Content ◽  
Element Model ◽  
Offshore Structures ◽  
Anoxic Environments ◽  
Electrochemical Parameters ◽  
Cathode Area ◽  
Optical Profilometer ◽  
Set Up ◽  
Corrosion Of Steel

Reinforced concrete may corrode in anoxic environments such as offshore structures. Under such conditions the reinforcement fails to passivate completely, irrespective of chloride content, and the corrosion taking place locally induces the growth of discrete pits. This study characterised such pits and simulated their growth from experimentally determined electrochemical parameters. Pit morphology was assessed with an optical profilometer. A finite element model was developed to simulate pit growth based on electrochemical parameters for different cathode areas. The model was able to predict long-term pit growth by deformed geometry set up. Simulations showed that pit growth-related corrosion tends to maximise as cathode area declines, which lower the pitting factor. The mechanical strength developed by the passive and prestressed rebar throughout its service life was also estimated. Passive rebar strength may drop by nearly 20% over 100 years, whilst in the presence of cracking from the base of the pit steel strength may decline by over 40%.

Finite Element Model of Human Cochlea Considering of the Helicotrema Size

2013 ◽  
Vol 456 ◽  
pp. 576-581 ◽  
Author(s):  
Li Fu Xu ◽  
Na Ta ◽  
Zhu Shi Rao ◽  
Jia Bin Tian
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Basilar Membrane ◽  
Round Window ◽  
Element Model ◽  
Oval Window ◽  
Fe Model ◽  
Cochlear Duct ◽  
Human Cochlea ◽  
Set Up

A 2-D finite element model of human cochlea is established in this paper. This model includes the structure of oval window, round window, basilar membrane and cochlear duct which is filled with fluid. The basilar membrane responses are calculated with sound input on the oval window membrane. In order to study the effects of helicotrema on basilar membrane response, three different helicotrema dimensions are set up in the FE model. A two-way fluid-structure interaction numerical method is used to compute the responses in the cochlea. The influence of the helicotrema is acquired and the frequency selectivity of the basilar membrane motion along the cochlear duct is predicted. These results agree with the experiments and indicate much better results are obtained with appropriate helicotrema size.

Study on the Prediction of Drilling Forces on Cortical Bone Based on Finite Element Simulation

2013 ◽  
Vol 589-590 ◽  
pp. 157-162
Author(s):  
Ya Hui Hu ◽  
Qing Yun Zhang ◽  
Xiao Yu Yue
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Feed Rate ◽  
Orthogonal Experiment ◽  
Element Model ◽  
Drilling Speed ◽  
Drilling Force ◽  
Drill Diameter ◽  
Potential Damage ◽  
Set Up

The changes of drilling forces during bone drilling provide a useful index for evaluating the risk of potential damage to the bone. The aim of the work is that an elastic-plastic dynamic finite element model is used to simulate the process of a drill bit drilling through the bone. The finite element model was set up in the Abaqus6.11; the prediction model of the drilling force was gotten by using the regression orthogonal experiment and data processing software Matlab7.0. Diverse values of drilling speed, feed rate and drill diameter are important factors which will lead to changes in the drilling forces. By controlling the drilling parameters can obtain the optimal drilling force. The results show that the diameter has the greatest influence on the drilling force, the drilling speed the second, the feed rate the last.

Carbon Nanotube Composites for Vibration Damping

2008 ◽  
Vol 47-50 ◽  
pp. 817-820 ◽  
Author(s):  
R.L. Dai ◽  
W.H. Liao
Keyword(s):  
Carbon Nanotube ◽  
Epoxy Resin ◽  
Dynamic Properties ◽  
Element Model ◽  
Vibration Damping ◽  
Segment Length ◽  
Pure Epoxy ◽  
Nanotube Composites ◽  
Carbon Nanotube Composites ◽  
Set Up

It has been found that the composites of carbon nanotubes (CNTs) and epoxy resin could greatly enhance damping ability while the stiffness is kept high. In this paper, carbon nanotube enhanced epoxy resin is fabricated. A testing apparatus for obtaining composite dynamic properties is set up. In particular, the loss factors are measured. Experimental results show that CNT additive can provide the composite with several times higher damping as compared with pure epoxy. A finite element model is built to simulate the composite damping. CNT diameter and segment length are investigated using the developed model. Results show that composite damping is insensitive to CNT segment length while the effect of CNT diameter on composite damping is significant.

scholarly journals Predicting Fusing Current for Encapsulated Wire Bonds under Transient Loads

2010 ◽  
Vol 2010 (1) ◽  
pp. 000486-000493 ◽  
Author(s):  
Aditi Mallik ◽  
Roger Stout
Keyword(s):  
Single Pulse ◽  
Element Model ◽  
Current Response ◽  
Temperature Dependent ◽  
Wire Bonds ◽  
Potential Failure ◽  
Different Dimensions ◽  
Transient Loads ◽  
The Wire ◽  
Set Up

For high power IC chips, as device size inevitably decreases, the wire diameter unfortunately must decrease due to the need of finer pitch wires. Fusing or melting of wirebonds thus increasingly becomes one of the potential failure issues for such IC's. Experiments were performed under transient loads on dummy packages having aluminum, gold, or copper wires of different dimensions. A finite element model was constructed that correlates very well with the observed maximum operating currents for such wirebonds under actual experimental test conditions. A qualitative observation of typical current profiles, as fusing conditions were approached, was that current would reach a maximum value very early in the pulse, and then fall gradually. One goal achieved through the modeling was to show that the current in the wire falls with time due to the heating of the wire material. Correspondingly, the wire reaches the melting temperature not at the peak current but rather at the end of pulse. Further, modeling shows that knowledge of external resistance and inductance of the experimental set up are highly significant in determining the details of a fusing event, but if known along with the temperature-dependent wire properties, the simulation can predict the correct voltage and current response of the part with 2% error. On the other hand, lack of external circuit characteristics may lead to completely incorrect results. For instance, the assumption that current is constant until the wire heats to fusing temperature, or that current and temperature both rise monotonically to maximum values until the wire fuses, are almost certain to be wrong. The work has been carried out for single pulse events as well as pulse trains.

Interaction of external head impact parameters on region and volume of strain for collisions in sport

2018 ◽  
Vol 233 (2) ◽  
pp. 258-267 ◽  
Author(s):  
R Anna Oeur ◽  
Michael D Gilchrist ◽  
Thomas Blaine Hoshizaki
Keyword(s):  
Brain Injuries ◽  
Element Model ◽  
Brain Regions ◽  
Peak Strain ◽  
Centre Of Gravity ◽  
Impact Parameters ◽  
Four Levels ◽  
Set Up ◽  
The Impact ◽  
Strain Responses

Collisions with the head are the primary cause of concussion in contact sports. Head impacts can be further characterized by velocity, striking mass, compliance, and location (direction). The purpose of this study was to describe the interaction effects of these parameters on peak strain in four brain regions and the volume of strain for collision impacts. A pendulum test set-up was used to deliver impacts to an adult Hybrid III headform according to four levels of mass (3, 9, 15, and 21 kg), four velocities (1.5, 3.0, 4.5, and 6.0 m/s), two impact locations (through the centre of gravity and a non-centre of gravity), and three levels of compliance simulating unprotected, helmeted, and well-padded conditions in sport. Headform accelerations were input into a brain finite element model to obtain peak strain in the frontal, temporal, parietal, and occipital lobes and the volume of the brain experiencing 0.10, 0.15, 0.20, and 0.25 strains. Centre-of-gravity impacts created the highest strains (peak and volume) under low compliance and non-centre-of-gravity impacts produced greater strain responses under medium and high compliance conditions. The temporal lobe was the region that consistently displayed the highest peak strains, which may be due to the proximity of the impact locations to this region. Interactions between mass and velocity displayed effects where the 9-kg mass had higher peak and volumes of strain than the 15-kg mass at velocities of 3.0 and 4.5 m/s. This study demonstrates the important role of interacting impact parameters on increasing strain responses that are relevant to the spectrum of diffuse brain injuries, including concussion.

scholarly journals Experimental Investigation on Hydrodynamic Coefficients of a Column-Stabilized Fish Cage in Waves

2019 ◽  
Vol 7 (11) ◽  
pp. 418
Author(s):  
Zhao ◽  
Chen ◽  
Bi ◽  
Cui
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Drag Force ◽  
Inertial Force ◽  
Element Model ◽  
Wave Force ◽  
Hydrodynamic Coefficients ◽  
Horizontal Wave ◽  
Horizontal Wave Force ◽  
The Finite Element Model

This study on hydrodynamic coefficients of a column-stabilized fish cage under wave action plays an important role in the anti-wave design of cages. The regular wave test was used to study the horizontal wave force of the jacket and column-stabilized fish cage under different wave heights, periods, and incident angles; the finite element model of the jacket and the column-stabilized fish cage was established according to the test model. On the basis of the calculation of the finite element model, combined with the wave force obtained from the experiment, the hydrodynamic coefficients of the structure was fitted by the least squares method, and then the drag force, inertial force, and total force of the structure under different conditions were calculated. The results show that the hydrodynamic coefficients of the jacket and netting under the wave condition were more obvious with the change of the KC number and wave incident angles. And as the wave height increased, the drag force, the inertial force, and the proportion of the drag force to the horizontal wave force both increased. When the wavelength was large, the same trend occured as the wave period increased. When the wave incident angles were different, the forces of the jacket and the column-stabilized fish cage were always small in lateral low-frequency waves, which is consistent with the change law of hydrodynamic coefficients of the jacket and netting.

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