Finite Element Simulation of Freezing Technology for Borehole Stability of Gas Drilling

2014 ◽  
Vol 962-965 ◽  
pp. 415-418
Author(s):  
Zong Gang Wang ◽  
Zhen Wei
Keyword(s):  
Finite Element ◽  
High Speed ◽  
Freezing Point ◽  
Drill String ◽  
Frozen Soil ◽  
Conductive Heat ◽  
Formation Water ◽  
Borehole Stability ◽  
Finite Element Program ◽  
Gas Drilling

The gas drilling mainly relies on the high speed air flow to carry the cuttings. The formation water or oil mixed with the cuttings and then they stick together in clumps after the formation water or oil went into the hole annulus, the clumps stick on the drill string and the borehole. The clumps may block the hole annulus and cause the stick or bury the drill string and many other complex accident. It could stop the cuttings from sticking with the liquid through freezing the formation fluid with the liquid nitrogen. And the natural geotechnical becomes into the frozen soil, and forms the temporary solid which is intact, high strength and low-permeability. This paper utilize the ANSYS finite element program to simulate the 3D model of borehole and hole wall to calculate the freezing radius of the steady state, heat loss, temperature of the freezing point and the conductive heat time of the unsteady state. And this study has provided the basis of the freezing technology for borehole stability of gas drilling.

Freezing Technology for Borehole Stability of Gas Drilling

2014 ◽  
Vol 962-965 ◽  
pp. 419-421
Author(s):  
Zong Gang Wang ◽  
Zhen Wei
Keyword(s):  
Fluid Flow ◽  
High Speed ◽  
High Strength ◽  
Drill String ◽  
Frozen Soil ◽  
Low Permeability ◽  
Formation Water ◽  
Borehole Stability ◽  
Gas Drilling ◽  
Scope Of Application

The gas drilling mainly relies on the high speed air flow to carry the cuttings. The formation water or oil mixed with the cuttings and then they stick together in clumps after the formation water or oil went into the hole annulus, the clumps stick on the drill string and the borehole. The clumps may block the hole annulus and cause the stick or bury the drill string and many other complex accident. It could stop the cuttings from sticking with the liquid through freezing the formation fluid with the liquid nitrogen. And the natural geotechnical becomes into the frozen soil, and forms the temporary solid which is intact, high strength and low-permeability. This technology could achieve the purpose of strengthening the formation and reducing the fluid flow of the formation, and it greatly broadens the scope of application of gas drilling.

Scheme Optimization of Freezing Technology for Borehole Stability of Gas Drilling

2014 ◽  
Vol 962-965 ◽  
pp. 465-468
Author(s):  
Zong Gang Wang ◽  
Zhen Wei
Keyword(s):  
High Speed ◽  
High Strength ◽  
Drill String ◽  
Frozen Soil ◽  
Low Permeability ◽  
Formation Water ◽  
Borehole Stability ◽  
Gas Drilling ◽  
Scheme Optimization ◽  
Drilling Technology

The gas drilling mainly relies on the high speed air flow to carry the cuttings. The formation water or oil mixed with the cuttings and then they stick together in clumps after the formation water or oil went into the hole annulus, the clumps stick on the drill string and the borehole. The clumps may block the hole annulus and cause the stick or bury the drill string and many other complex accident. It could stop the cuttings from sticking with the liquid through freezing the formation fluid with the liquid nitrogen. And the natural geotechnical becomes into the frozen soil, and forms the temporary solid which is intact, high strength and low-permeability. In this paper, according to the characteristic of the gas drilling technology, we optimized the scheme of freezing technology for borehole stability to give the theoretical basis of the industrial application.

Freezing Technology for Borehole Stability of Gas Drilling

2013 ◽  
Vol 433-435 ◽  
pp. 1995-1998
Author(s):  
Zong Gang Wang ◽  
Zhen Wei
Keyword(s):  
Fluid Flow ◽  
High Speed ◽  
High Strength ◽  
Drill String ◽  
Frozen Soil ◽  
Low Permeability ◽  
Formation Water ◽  
Borehole Stability ◽  
Gas Drilling ◽  
Scope Of Application

The gas drilling mainly relies on the high speed air flow to carry the cuttings. The formation water or oil mixed with the cuttings and then stick together in clumps after the formation water or oil went into the hole annulus, the clumps stick on the drill string and the borehole. The clumps may block the hole annulus and cause the stick or bury the drill string and many other complex accident. It could stop the cuttings from sticking with the liquid through freezing the formation fluid with the liquid nitrogen. And the natural geotechnical becomes into the frozen soil, and forms the temporary solid which is intact, high strength and low-permeability. This technology could achieve the purpose of strengthening the formation and reducing the fluid flow of the formation, and it greatly broadens the scope of application of gas drilling.

The Finite Element Analysis of Dynamic Interaction of High-Speed Shinkansen, the Rail, and Bridge

1993 ◽  
Author(s):  
Makoto Tanabe ◽  
Hajime Wakui ◽  
Nobuyuki Matsumoto
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
High Speed ◽  
Response Analysis ◽  
Element Formulation ◽  
Element Analysis ◽  
Finite Element Program ◽  
The Finite Element Analysis ◽  
Element Program ◽  
The Impact

Abstract A finite element formulation to solve the dynamic behavior of high-speed Shinkansen cars, rail, and bridge is given. A mechanical model to express the interaction between wheel and rail is described, in which the impact of the rail on the flange of wheel is also considered. The bridge is modeled by using various finite elements such as shell, beam, solid, spring, and mass. The equations of motions of bridge and Shinkansen cars are solved under the constitutive and constraint equations to express the interaction between rail and wheel. Numerical method based on a modal transformation to get the dynamic response effectively is discussed. A finite element program for the dynamic response analysis of Shinkansen cars, rail, and bridge at the high-speed running has been developed. Numerical examples are also demonstrated.

The role of material model in the finite element simulation of high-speed machining of Ti6Al4V

2016 ◽  
Vol 230 (17) ◽  
pp. 2959-2967 ◽  
Author(s):  
Chong-Yang Gao ◽  
Liang-Chi Zhang ◽  
Peng-Hui Liu
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
High Speed ◽  
Material Model ◽  
Machining Process ◽  
High Speed Machining ◽  
Serrated Chip ◽  
Finite Element Program ◽  
Element Simulation ◽  
Improved Model

This paper provides a comprehensive assessment on some commonly used thermo-viscoplastic constitutive models of metallic materials during severe plastic deformation at high-strain rates. An hcp model previously established by us was improved in this paper to enhance its predictability by incorporating the key saturation characteristic of strain hardening. A compensation-based stress-updating algorithm was also developed to introduce the new hcp model into a finite element program. The improved model with the developed algorithm was then applied in finite element simulation to investigate the high-speed machining of Ti6Al4V. It was found that by using different material models, the simulated results of cutting forces, serrated chip morphologies, and residual stresses can be different too and that the improved model proposed in this paper can be applied to simulate the titanium alloy machining process more reliably due to its physical basis when compared with some other empirical Johnson–Cook models.

scholarly journals A Study of Coupled Creep Damaged Constitutive Model of Artificial Frozen Soil

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Dongwei Li ◽  
Junhao Chen ◽  
Yan Zhou
Keyword(s):  
Finite Element ◽  
Constitutive Model ◽  
Damage Mechanics ◽  
Yield Criterion ◽  
Creep Damage ◽  
Confining Pressure ◽  
Frozen Soil ◽  
Finite Element Program ◽  
Finite Element Software ◽  
Frozen Clay

Artificial frozen soil is a kind of typical creep material, and the frozen clay under the unloading stress paths of high-confining pressure conforms to the improved the Zienkiewicz–Pande parabola-type yield criterion, and the Mohr–Coulomb yield function can describe the shear yield surface of artificial frozen clay under low-confining pressure. Based on the results of triaxial creep and shear tests for artificial frozen soil, the viscoplastic damage variable and evolution rule of artificial frozen clay were obtained by using the theory of viscoelastic-plastic mechanics and damage mechanics. An improved Zienkiewicz–Pande parabola-type yield criterion was used instead of a linear Newton body to obtain a coupled constitutive model of viscoelastic-plastic damage in the frozen soil under the unloading stress paths and to derive the coupling flexibility matrix for viscoelastic and viscoplastic damage. A finite element program of artificial frozen soil considering creep damage was written in the Visual Fortran 6.6A environment and embedded into the nonlinear finite element software ADINA as a user subroutine. The results of numerical simulation and laboratory testing were identical, with a maximum error of no more than 4.8%. This work shows that it is reasonable to describe the creep constitutive model of frozen soil with the viscoelastic-plastic-coupled constitutive model.

High Speed Impact Characteristics of Plastic Material Based on Finite Element Simulation

2011 ◽  
Vol 383-390 ◽  
pp. 3229-3233 ◽  
Author(s):  
Waluyo Adi Siswanto ◽  
Rodzilla Y. Sharafuddin ◽  
Perowansa Paruka
Keyword(s):  
Finite Element ◽  
High Speed ◽  
Plastic Material ◽  
Strain History ◽  
Finite Element Program ◽  
High Speed Impact ◽  
Element Simulation ◽  
Material Specimen ◽  
Element Program ◽  
As Stress

Testing material specimen on impact using high speed puncture machine can be used to observe the ability of material to withstand under a certain impact speed by looking at the energy required to tear the material. Other detail parameters such as stress, strain and tearing development on impact cannot be seen or measured. This paper presents a finite element method approach to see the strain history and the tearing sequence that cannot be obtained during impact puncture testing of plastic material (Polyethylene Terephthalate / PET). Simulations in different speed; 10 m/s (36 km/h) and 20 m/s (72 km/h) are performed employing a dynamic-explicit Impact finite element program suite. The simulations are able to capture the tearing process, to see the strain histories of tearing region and to predict the tearing pattern. The tearing pattern simulation results are verified by comparing with that from experiment.

ROTOR RESONANCES ANALYSES OF HIGH-SPEED HIGH POWER PERMANENT-MAGNET ELECTRICAL MACHINES

2021 ◽  
pp. 95-108
Author(s):  
Wedad Alsadiq Alhawil ◽  
Ali A. Mehna ◽  
Asheraf Eldieb ◽  
Tarak Assaleh
Keyword(s):  
Finite Element ◽  
Permanent Magnet ◽  
High Speed ◽  
Natural Frequencies ◽  
Design Stage ◽  
Design Parameters ◽  
Element Analysis ◽  
Finite Element Program ◽  
Element Program ◽  
The Impact

High-speed electric machines (HSEMs) have been widely used in many of today’s applications.  For high-speed machines, in particular, it is very important to accurately predict natural frequencies of the rotor at the design stage to minimize the likelihood of failure. The main goal of this study is examine the design issues and performance of high-speed machines. For permanent-magnet synchronous motors (PMSM) driven by high-frequency drives, the rotor speed is normally above 30 000 rpm and it may exceed 100 000 rpm.  This study examined a 7-kw permanent magnet synchronous machine at 200,000 rpm. 3D finite element analysis (ANSYS WORKBENCH 15) was conducted to determine the natural frequencies and rotor patterns of a synchronous high-speed permanent magnetic motor, to assess the impact of leading design parameters, such as length, column diameter, span, bearings, material properties, and to compare the results of the finite element program with the results of analytical methods (i.e. critical speed).

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