Effects of tool eccentralization on cement-bond-log measurements: Numerical and experimental results

Geophysics ◽  
2013 ◽  
Vol 78 (4) ◽  
pp. D181-D191 ◽  
Author(s):  
Ruo-Long Song ◽  
Ji-Sheng Liu ◽  
Xiu-Mei Lv ◽  
Xiu-Tian Yang ◽  
Ke-Xie Wang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Finite Difference ◽  
Quality Evaluation ◽  
Horizontal Wells ◽  
Simulation Method ◽  
Experimental Results ◽  
Vertical Wells ◽  
The World ◽  
Fluid Channel ◽  
The Relationship

The cement-bond log (CBL) is a conventional and widely used cement quality evaluation technology for vertical wells. With the increase in horizontal wells around the world, the existing cement evaluation technologies are not appropriate. We have explored the possibilities of utilizing CBL in horizontal wells through investigating the effects of a noncentralized tool on CBL measurements. The parallel finite-difference numerical simulation method and experiments in calibration wells were adopted in the study. The numerical and experimental results matched very well, and indicated that the CBL amplitude decreases linearly with increasing tool eccentricity in a well with free pipe (i.e., a cased but uncemented well). For a standard pipe with a diameter of 5.5 in (139.7 mm) and a thickness of 7.72 mm, an eccentricity of [Formula: see text] (17% of the maximum eccentricity) could cause the CBL amplitude to be reduced by about 20%. The numerical simulations of CBL in wells with fluid channels in the cement showed that tool eccentralization could either increase or reduce the CBL amplitude relative to a centered tool, depending on the channel azimuth relative to eccentered direction. To explain this phenomenon, we investigated numerically the polarizations of casing waves in a well with free pipe and in a well with a fluid channel, and casing waves at higher frequencies in a well with free pipe. The relationship between the CBL amplitude and the percentage of cemented area for a borehole-centered tool was also studied. Our results provided some insights into understanding CBL measurements in horizontal wells.

scholarly journals Influence of Backing Plate Support Conditions on Armor Ceramic Protection Efficiency

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3427
Author(s):  
Bowen Zhang ◽  
Yangwei Wang ◽  
Shaofeng Du ◽  
Zhikun Yang ◽  
Huanwu Cheng ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Composite Ceramic ◽  
Simulation Method ◽  
Mechanical Support ◽  
Protection Efficiency ◽  
Positive Correlation ◽  
Backing Plate ◽  
The World ◽  
Support Conditions ◽  
The Relationship

The bilayer composite ceramic armor is widely used in the world, while the protection efficiency of the armor ceramic in it still confuses researchers. This study applied a numerical simulation method to produce a general equation that describes the relationship between the protection efficiency of the armor ceramic and the supporting conditions of the backing plate, thereby enhancing the current understanding of the composite ceramic armor. The results indicated that the protection efficiency of the armor ceramic can be divided into three parts: (1) the basic protection efficiency, (2) the increment efficiency caused by inertial support, and (3) the increment efficiency caused by mechanical support. The inertial support is related to the density and thickness of the backing plate, and the mechanical support is related to the elastic modulus and yield strength of the backing plate materials. The inertial support exhibited a positive correlation with the protection efficiency of the armor ceramic before it reached the Scr; after that, the protection efficiency of the armor ceramic would remain stable. In addition, the mechanical support showed a linear, positive correlation with the backing plate stress at ε0.

Numerical Simulation for Uplift Bearing Capacity and Affecting Factors of the Digging Piles in Slope Ground

2013 ◽  
Vol 423-426 ◽  
pp. 1292-1295 ◽  
Author(s):  
Xing Yun Wang ◽  
Bin Peng ◽  
Xiao Chao Tang ◽  
Lian Fan
Keyword(s):  
Numerical Simulation ◽  
Regression Analysis ◽  
Finite Difference ◽  
Bearing Capacity ◽  
Mutual Effect ◽  
Simulation Method ◽  
Affecting Factors ◽  
Slope Ratio ◽  
Nonlinear Regression Analysis ◽  
Numerical Simulation Method

Based on the numerical simulation method, this paper has established the numerical simulation method by using of finite difference software of FLAC3D through establishing interface for digging pile-soil. It can consider mutual effect of digging pile-soil. The uplift bearing capacity of the digging pile in slope ground was calculated and the affecting factors of the bearing capacity were analyzed. The results show that the uplift bearing capacity has a negative correlation with the slope ratio, and has a positive correlation with the width or height of the foundation, which can be expressed as a quadratic polynomial. But when the slope ratio is smaller than a certain extent, the capacity no longer increases. Nonlinear regression analysis of calculation data are carried out. Finally, the calculation method of uplift bearing capacity about pile in the slope is developed, which can provide a reference to specification revision and engineering.

Experimental and numerical investigation of the thermomechanical load on a turbine housing in a radial turbocharger

2021 ◽  
pp. 095440702110521
Author(s):  
Shaolin Chen ◽  
Hong Zhang ◽  
Liaoping Hu ◽  
Guangqing He ◽  
Fen Lei ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Fatigue Life ◽  
Simulation Analysis ◽  
Simulation Method ◽  
Testing Temperature ◽  
Experimental Results ◽  
Maximum Temperature ◽  
Monitoring Point ◽  
Turbine Housing

The fatigue life of turbine housing is an important index to measure the reliability of a radial turbocharger. The increase in turbine inlet temperatures in the last few years has resulted in a decrease in the fatigue life of turbine housing. A simulation method and experimental verification are required to predict the life of a turbine housing in the early design and development process precisely. The temperature field distribution of the turbine housing is calculated using the steady-state bidirectional coupled conjugate heat transfer method. Next, the temperature field results are considered as the boundary for calculating the turbine housing temperature and thermomechanical strain, and then, the thermomechanical strain of the turbine housing is determined. Infrared and digital image correlations are used to measure the turbine housing surface temperature and total thermomechanical strain. Compared to the numerical solution, the maximum temperature RMS (Root Mean Square) error of the monitoring point in the monitoring area is only 3.5%; the maximum strain RMS error reached 11%. Experimental results of temperature field test and strain measurement test show that the testing temperature and total strain results are approximately equal to the solution of the numerical simulation. Based on the comparison between the numerical calculation and experimental results, the numerical simulation and test results were found to be in good agreement. The experimental and simulation results of this method can be used as the temperature and strain (stress) boundaries for subsequent thermomechanical fatigue (TMF) simulation analysis of the turbine housing.

scholarly journals Study on Penetration Performance of Rear Shaped Charge Warhead

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6526
Author(s):  
Yanan Du ◽  
Guanglin He ◽  
Yukuan Liu ◽  
Zhaoxuan Guo ◽  
Zenghui Qiao
Keyword(s):  
Numerical Simulation ◽  
Experimental Verification ◽  
Simulation Method ◽  
Shaped Charge ◽  
Experimental Results ◽  
Target Plate ◽  
Depth Of Penetration ◽  
Steel Target ◽  
Shaped Charge Jet ◽  
Control Cabin

In guided munitions, the shaped charge jet (SCJ) warhead is located behind the simulation compartment (including the control cabin, the steering gear cabin, and the guidance cabin). Therefore, the order of penetration of the SCJ is the simulation cabin and the target. To study the penetration performance of the SCJ to the target plate, the numerical simulation method is used to study the penetration performance of the designed warhead for the steel target at different standoffs, and the depth of penetration (DOP) at the best standoff is obtained, that is, the DOP of the steel target is about 128 mm. Additionally, the penetration performance of the SCJ warhead to target is studied by numerical simulation and experimental verification. Numerical simulation and experimental results show that the DOP of the SCJ warhead to the steel target is 50 mm without the simulation cabin, and about 30 mm with the simulation cabin. The results show that the penetration performance of SCJ is greatly weakened under the condition of non-optimal standoff, but the rear shaped charge warhead still has a strong penetration performance after completing the penetration of the simulated cabin.

scholarly journals Three-Dimensional Numerical Simulation of Multiscale Fractures and Multiphase Flow in Heterogeneous Unconventional Reservoirs with Coupled Fractal Characteristics

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Hong Li ◽  
Haiyang Yu ◽  
Nai Cao ◽  
Shiqing Cheng ◽  
He Tian ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Multiphase Flow ◽  
Water Saturation ◽  
Three Dimensional ◽  
Horizontal Wells ◽  
Simulation Method ◽  
Fractal Model ◽  
Point Pattern ◽  
Permeability Model ◽  
Heterogeneous Model

A simulated reservoir model, based on the permeability fractal model and three-dimensional (3D) Gaussian filter, was established to account for in-layer and interlayer heterogeneity so that the result conforms to the law of geological statistics. Combined with an embedded discrete fracture method (EDFM), a multiscale fracture system was established, forming the numerical simulation method of multiphase flow in horizontal wells in heterogeneous reservoirs with complex fractures. The heterogeneity and saturation of the reservoir mixed five-point pattern of vertical and horizontal wells and the injection and production of horizontal wells were discussed. The results show that it is difficult to characterize complex reservoirs using a homogeneous permeability model. Thus, it is best to use a heterogeneous model that considers permeability differences in tight reservoirs. Formation fluids coexist in multiple phases, and water saturation has a direct effect on the production. Thus, a multiphase flow model is needed and can play a greater role in injection and production technology. The mixed five-point pattern of vertical and horizontal wells can improve productivity to a certain extent, but the dual effects of heterogeneity and fracturing will cause a decline in production by accelerating the communication of injected fluid. The reservoir is heterogeneous between wells, and there are differing effects on adjacent wells. Therefore, near-well natural microfractures are opened because of fracturing in horizontal wells, and the heterogeneity cannot be ignored, especially when multiple wells are simultaneously injected and produced.

Experiment and numerical simulation of the combined effect of winding, cool-down, and screening current induced stresses in REBCO coils

2022 ◽  
Author(s):  
Hiroshi Ueda ◽  
Hideaki Maeda ◽  
Yu Suetomi ◽  
Yoshinori Yanagisawa
Keyword(s):  
Numerical Simulation ◽  
Circumferential Stress ◽  
Simulation Method ◽  
Experimental Results ◽  
Combined Effect ◽  
Beneficial Effects ◽  
Modification Effect ◽  
Operating Current ◽  
Induced Stresses ◽  
Coil Winding

Abstract This paper overviews the combined effect of winding, cool-down, and screening current-induced stresses in REBCO coils. First, a simulation method to model the circumferential stress modification effect due to the screening-current is overviewed. The simulation includes coil winding, cooling down, and coil charge up to the operating current. Second, we will compare the numerical simulation results with the experimental results. The numerical simulations for a dry coil and an epoxy impregnated coil agree well with the experimental results. Third, the enhanced circumferential stress did not degrade the performance of a dry winding REBCO coil, but. the improved increased compressive stress buckled the coil structure. Finally, it is demonstrated that epoxy impregnation has beneficial effects in reducing the stress modification effect. However, the circumferential stress is enormously enhanced at the coil ends, sometimes resulting in degradation of the coil performance.

Study on Experiment and Simulation for Laser Surface Micro Texturing on Cylinder Piston Ring Friction Pair

2014 ◽  
Vol 1033-1034 ◽  
pp. 1317-1320
Author(s):  
Wei Gong ◽  
Fei Dong ◽  
Yun Peng Du ◽  
Ji Lin Xiong
Keyword(s):  
Numerical Simulation ◽  
Laser Pulse ◽  
Piston Ring ◽  
Friction Pair ◽  
Simulation Method ◽  
Experimental Results ◽  
Pulse Interval ◽  
Numerical Simulation Method ◽  
Cylinder Piston ◽  
Micro Cavity

Regarding the cylinder piston ring friction pair system as the object , put forward a new numerical simulation method to study the thermal effect mechanism of single pulse interval laser micro texturing. By means of numerical simulation and experimental verification, analysis the variation of laser pulse frequency and laser power on the 45# steel surface micro cavity morphology. The simulation and experimental results show that along with the increase of laser pulse number, the depth of micro cavity increases, the recasting phenomenon of molten metal is obvious, and the machined surface quality decreases. At the same condition, the micro cavity depth simulation results and experimental results are basically the same trend; the maximum error is less than 8%, which proves the feasibility and validity of the numerical simulation method.

Numerical Simulation for DC PD in Void

2013 ◽  
Vol 448-453 ◽  
pp. 1982-1987
Author(s):  
Jin Zhong Li ◽  
Shu Qi Zhang ◽  
Rui Guo ◽  
Hao Tang ◽  
Tao Zhao ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Finite Difference ◽  
Finite Difference Method ◽  
Repetition Rate ◽  
Electric Field Distribution ◽  
Time Interval ◽  
Stochastic Property ◽  
Dc Voltage ◽  
The Finite Difference Method ◽  
The Relationship

A numerical simulation for DC PD in void is put forward based on the PD physical process. The finite difference method is used to calculate the electric field distribution, and both of the stochastic property and the accumulation of the charge after PD on the void surfaces are considering in the model. The time of PD occurring, the amount of discharge and the voltage across the void are calculated. Meanwhile, the relationship between the DC voltage and the PD time interval or repetition rate is also simulation, the results show that with the increase of the DC voltage, the PD interval corresponding decreases exponentially and the repetition rate increases exponentially.

Research on Relationship between Weight Filter Function and Stiffness Filter Function

2011 ◽  
Vol 411 ◽  
pp. 580-583
Author(s):  
Zhen Shang ◽  
Yun Kang Sui
Keyword(s):  
Numerical Simulation ◽  
Topology Optimization ◽  
Least Squares Method ◽  
Simulation Method ◽  
Homogenization Method ◽  
Structural Topology Optimization ◽  
Structural Topology ◽  
Filter Function ◽  
The Impact ◽  
The Relationship

Combined with the homogenization method and the least squares method, the filter function with the form of power function is studied in the Independent Continuum Map (ICM) method. Then, the numerical simulation method is used to study the relationship between a weight filter function and a stiffness filter function. Finally, the impact of the filtration function on the efficiency of topology optimization is showed by examples. It is important to further research structural topology optimization.

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