Analytical investigation of well/perforation scale effect on sand production of weakly consolidated sandstones

2016 ◽  
Vol 56 (1) ◽  
pp. 405 ◽  
Author(s):  
Soroush Tehrani ◽  
Mohammad Sarmadivaleh ◽  
Ahmadreza Younessi Sinaki ◽  
Masood Mostofi ◽  
Massoud Bayati
Keyword(s):  
Scale Effect ◽  
Analytical Approach ◽  
Failure Criteria ◽  
Analytical Investigation ◽  
Experimental Results ◽  
Outer Diameter ◽  
Sand Production ◽  
Effect Factor ◽  
Open Hole ◽  
Walled Cylinder

Investigating the risk of sand production is a common practice for developing unconsolidated and weakly consolidated reservoirs, particularly with designing the completion system of development wells. The risk of sanding may be different for open hole and cased and perforated completion systems. Part of this difference is a result of the different size of the boreholes—that is, open hole versus perforation tunnels— which is known as borehole scale effect. The amount of research dedicated to investigate the borehole scale effect on sand production is very limited. Research has been carried out by conducting thick-walled cylinder (TWC) tests on samples with different inner to outer diameter ratios. The impacts of sample size and boundaries on the induced stresses around the borehole and failure were, however, not differentiated from the borehole scale effect. In this paper, a comprehensive analytical approach is performed to investigate the effect of the size of the sample and boundaries on TWC tests and borehole failure. To do this, four different failure criteria—Mohr-Coulomb, Drucker-Prager, Mogi and modified Lade—are compared with previously published experimental results. The analysis shows that the size of the sample and the boundaries may significantly change the TWC strength of the rock. The TWC changes by different inner to outer diameter ratios, however, may not be fully justified by the analytical approach. Hence, a scale effect factor must be introduced to replicate the experimental results.

scholarly journals Analytical investigation of high-velocity impact on hybrid unidirectional/woven composite panels

2016 ◽  
Vol 30 (4) ◽  
pp. 545-563 ◽  
Author(s):  
H Shanazari ◽  
GH Liaghat ◽  
H Hadavinia ◽  
A Aboutorabi
Keyword(s):  
Cross Sections ◽  
Shear Failure ◽  
Failure Criteria ◽  
Analytical Investigation ◽  
Woven Fabrics ◽  
Body Armor ◽  
Ballistic Performance ◽  
Nonwoven Fabrics ◽  
Ballistic Protection ◽  
Maximum Tensile Strain

In addition to fiber properties, the fabric structure plays an important role in determining ballistic performance of composite body armor textile. Textile structures used in ballistic protection are woven fabrics, unidirectional (UD) fabric structures, and nonwoven fabrics. In this article, an analytical model based on wave propagation and energy balance between the projectile and the target is developed to analyze hybrid fabric panels for ballistic protection. The hybrid panel consists of two types of structure: woven fabrics as the front layers and UD material as the rear layers. The model considers different cross sections of surface of the target in the woven and UD fabric of the hybrid panel. Also the model takes into account possible shear failure by using shear strength together with maximum tensile strain as the failure criteria. Reflections of deformation waves at interface between the layers and also the crimp of the yarn are modeled in the woven part of the hybrid panel. The results show greater efficiency of woven fibers in front layers (more shear resistance) and UD yarns in the rear layers (more tensile resistance), leading to better ballistic performance. Also modeling the yarn crimp results in more trauma at the backface of the panel producing data closer to the experimental results. It was found that there is an optimum ratio of woven to UD materials in the hybrid ballistic panel.

Study of Sand Production Using Geomechanical and Hydro-Mechanical Models

2018 ◽  
Vol 876 ◽  
pp. 181-186
Author(s):  
Son Tung Pham
Keyword(s):  
Production Rate ◽  
Mechanical Model ◽  
Failure Criteria ◽  
Sand Production ◽  
Geomechanical Model ◽  
Strength Failure ◽  
Rate Versus ◽  
Mechanical Models ◽  
Rock Mechanical Properties ◽  
Bottomhole Pressure

Sand production is a complicated physical process depending on rock mechanical properties and flow of fluid in the reservoir. When it comes to sand production phenomenon, many researchers applied the Geomechanical model to predict the pressure for the onset of sand production in the reservoir. However, the mass of produced sand is difficult to determine due to the complexity of rock behavior as well as fluid behavior in porous media. In order to solve this problem, there are some Hydro – Mechanical models that can evaluate sand production rate. As these models require input parameters obtained by core analysis and use a large empirical correlation, they are still not used popularly because of the diversity of reservoirs behavior in the world. In addition, the reliability of these models is still in question because no comparison between these empirical models has been studied. The onset of sand production is estimated using the bottomhole pressure that makes the maximum effective tangential compressive stress equal or higher than the rock strength (failure criteria), which is usually known as critical bottomhole pressure (CBHP). Combining with Hydro – Mechanical model, the main objective of this work aims to develop a numerical model that can solve the complexity of the governing equations relating to sand production. The outcome of this study depicts sand production rate versus time as well as the change of porosity versus space and time. In this paper, the Geomechanical model coupled with Hydro – Mechanical model is applied to calibrate the empirical parameters.

scholarly journals Open-Hole 3D Braided Composites Strength Prediction and Stress Analysis

2020 ◽  
Vol 38 (4) ◽  
pp. 889-896
Author(s):  
Shuangqiang Liang ◽  
Chenglong Zhang ◽  
Ge Chen ◽  
Qihong Zhou ◽  
Frank Ko
Keyword(s):  
Failure Analysis ◽  
Progressive Failure ◽  
Failure Criteria ◽  
Element Analysis ◽  
Braided Composite ◽  
Failure Initiation ◽  
Geometry Model ◽  
Progressive Failure Analysis ◽  
3D Braided Composites ◽  
Open Hole

The stress concentration caused by notches is a common engineering issue for composite structure application. 3D braided composite possess excellent damage tolerance compared to common laminates. The tensile properties of 3D braided composite with open-hole and un-notched were experimentally examined. The mechanic properties of 3D braided composite in other directions are predicted using FGM (Fabric Geometry Model) and finite element analysis. The stress distributions around the hole and perpendicular to the loading direction are analyzed based on Abaqus software. The simulation results were compared with Lekhnitskii's analytical study. The open-hole strength of 3D braided composite was predicted respectively using Average stress failure criteria, Point stress failure criteria (PSC), and also the progressive failure analysis based on different failure criteria. The predicted strength results were compared to the experimental values. The results show the PSC predicted strength matched the experiment, while the progressive failure analysis can predict the failure initiation, propagation and final failure mode.

scholarly journals Investigation of Sheet Metal Forming Using a Rapid Compression Machine

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3957 ◽  
Author(s):  
Sandeep P. Patil ◽  
Yann Fenard ◽  
Shridhar Bailkeri ◽  
Karl Alexander Heufer ◽  
Bernd Markert
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Peak Pressure ◽  
Experimental Results ◽  
Maximum Height ◽  
Outer Diameter ◽  
Rapid Compression Machine ◽  
Damage Initiation ◽  
Rapid Compression

The primary goal of this work is to understand the deformation behavior of an aluminum alloy (Al) workpiece by using a rapid compression machine (RCM). The primary novelty in this work is that this is the first study on sheet metal forming using RCM. Numerical simulation and experimental results are in excellent agreement, e.g., the dome-shape, the maximum height, the final outer diameter, and the thickness distribution of the deformed workpiece. We demonstrate that the maximum deformation height grows linearly with the peak pressure with an intercept tending to zero. The proposed linear relationship can be effectively used for designing new components for a specific application. Moreover, the proposed numerical model was competent in reproducing the experimental results of damage initiation and evolution in case of high peak pressure as well as the initial misalignment of the workpiece. The results of this investigation revealed that a rapid compression machine can be utilized efficiently for the controlled forming of complex shapes of metal sheets.

Notes on analytical treatment of black hole shadow

2018 ◽  
Vol 27 (10) ◽  
pp. 1844020 ◽  
Author(s):  
Oleg Yu. Tsupko
Keyword(s):  
Black Hole ◽  
Analytical Approach ◽  
September 11 ◽  
High Energy ◽  
Analytical Investigation ◽  
Analytical Treatment ◽  
Relativistic Outflows ◽  
Definition Of

In this work, we present and discuss recent results of analytical investigations of black hole (BH) shadow. First of all, we discuss definition of shadow in details. Then, we describe fully analytical approach for extraction of spin of BH from the deformation of its shadow. Finally, we present analytical investigation of plasma influence on the shadow size. This paper is based on talk given at the conference ‘High-Energy Phenomena in Relativistic Outflows VI', September 11–15, 2017, Moscow, Russia.

An Approximate Model for an Elastic-Plastic Pipe Element Under Combined Loading

1975 ◽  
Vol 97 (1) ◽  
pp. 22-28 ◽  
Author(s):  
L. D. Larson ◽  
W. F. Stokey ◽  
W. E. Franzen
Keyword(s):  
Strain Hardening ◽  
Axial Load ◽  
Analytical Approach ◽  
Limit Load ◽  
Approximate Model ◽  
Experimental Results ◽  
Combined Loading ◽  
Elastic Plastic ◽  
Plastic Pipe ◽  
Plastic Analysis

An approximate model for the elastic-plastic analysis of a pipe element under combined loading is developed. The model is obtained by generalizing a limit load solution for combined pressure, bending, torsion and axial load to include strain hardening. For various combinations of loading of tubes, curvatures and twist angles are predicted and compared with experimental results and those predicted by a more rigorous analytical approach. The comparison shows that good results are obtained from the approximate model.

Experimental and Analytical Investigation on Spaghetti Problem

2001 ◽  
Author(s):  
Yoshimasa Komaki ◽  
Nobuyuki Kobayashi ◽  
Masahiro Watanabe
Keyword(s):  
Dynamic Behavior ◽  
Multibody Dynamics ◽  
Constant Velocity ◽  
Analytical Investigation ◽  
Experimental Results ◽  
Flexible Beam ◽  
Gap Size ◽  
Lateral Vibration ◽  
Elastic Wall ◽  
Pulling Velocity

Abstract The dynamic behavior of the flexible beam, which is pulled into the slit of the elastic wall with a constant velocity, is discussed with multibody dynamics formulation and experiments. The vibration of the free tip of a flexible beam increases rapidly as pulling into the slit, and this behavior is called “Spaghetti Problem”. The effect of gap size of the slit on the behavior of Spaghetti Problem is especially focused. Dynamic behavior of the beam is simulated numerically and examined the accuracy of the presented formulation by changing the gap size and the pulling velocity of the beam as parameters. It is clarified that the presented modeling method simulates the experimental results quite well, and the gap size and the pulling velocity influence the increase of the lateral vibration near the inlet of the slit.

Progressive failure analysis of fiber-reinforced laminated composites containing a hole

2017 ◽  
Vol 27 (7) ◽  
pp. 963-978 ◽  
Author(s):  
Hadi Bakhshan ◽  
Ali Afrouzian ◽  
Hamed Ahmadi ◽  
Mehrnoosh Taghavimehr
Keyword(s):  
Failure Analysis ◽  
Failure Modes ◽  
Progressive Failure ◽  
Composite Plates ◽  
Failure Criteria ◽  
Element Analysis ◽  
Progressive Failure Analysis ◽  
Numerical Predictions ◽  
Open Hole ◽  
Failure Loads

The present work aims to obtain failure loads for open-hole unidirectional composite plates under tensile loading. For this purpose, a user-defined material model in the finite element analysis package, ABAQUS, was developed to predict the failure load of the open-hole composite laminates using progressive failure analysis. Hashin and modified Yamanda-Sun’s failure criteria with complete and Camanho’s material degradation model are studied. In order to achieve the most accurate predictions, the influence of failure criteria and property degradation rules are investigated and failure loads and failure modes of the composites are compared with the same experimental test results from literature. A good agreement between experimental results and numerical predictions was observed.

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