Radial profiling of the three formation shear moduli and its application to well completions

Geophysics ◽  
2006 ◽  
Vol 71 (6) ◽  
pp. E65-E77 ◽  
Author(s):  
Bikash K. Sinha ◽  
Badarinadh Vissapragada ◽  
Lasse Renlie ◽  
Sveinung Tysse
Keyword(s):  
Shear Modulus ◽  
Mechanical Damage ◽  
Vertical Shear ◽  
Horizontal Shear ◽  
Stress Concentrations ◽  
Shear Moduli ◽  
Anisotropic Formation ◽  
Mobility Impaired ◽  
Well Completions ◽  
Optimum Production

Near-wellbore alteration in shear stiffnesses in the three orthogonal planes can be described in terms of radial variations of the three shear moduli or slownesses. The three shear moduli are different in formations exhibiting orthorhombic or lower degree of symmetry, as is the case in deviated wellbores in triaxially stressed formations. These shear moduli are affected by factors such as overbalanced drilling, borehole stress concentrations, shale swelling, near-wellbore mechanical damage, and supercharging of permeable formations. The two vertical shear moduli [Formula: see text] and [Formula: see text] in an anisotropic formation with a vertical [Formula: see text]-axis are obtained from crossed-dipole sonic data, whereas the horizontal shear modulus [Formula: see text] is estimated from borehole Stoneley data. The effective shear modulus [Formula: see text] is smaller than the vertical shear moduli [Formula: see text] or [Formula: see text] in a poroelastic formation exhibiting high horizontal fluid mobility. Consequently, analyses of radial profiling of the three shear moduli in a reasonably uniform lithology interval yield useful correlations, with mobility impaired by an increased amount of clay or by near-wellbore damage in a shaley sand reservoir interval in a North Sea vertical well. Radial profiling results help to identify suitable depths for fluid sampling and to complete a well for optimum production.

scholarly journals Estimation of quadriceps femoris muscle dysfunction in the early period after surgery of the knee joint using shear-wave elastography

2018 ◽  
Vol 4 (1) ◽  
pp. e000381 ◽  
Author(s):  
Makoto Kawai ◽  
Keigo Taniguchi ◽  
Tomoyuki Suzuki ◽  
Masaki Katayose
Keyword(s):  
Shear Modulus ◽  
Knee Joint ◽  
Patient Group ◽  
Quadriceps Femoris ◽  
Control Group ◽  
Muscle Dysfunction ◽  
Shear Moduli ◽  
Quadriceps Femoris Muscle ◽  
Contraction Ratio ◽  
Femoris Muscle

ObjectivesOrthopaedic surgery of the knee joint results in functional deterioration of the quadriceps femoris muscle. However, little is known about quadriceps femoris muscle dysfunction in the early postsurgical period. Therefore, we examined the stiffness of the quadriceps femoris muscle in the early postsurgical period.MethodsSeven patients and seven healthy controls performed quadriceps contraction exercises. In resting and contraction conditions, the shear modulus, muscle thickness and pennation angle were measured for the vastus medialis (VM), vastus lateralis (VL) and the rectus femoris (RF) using ultrasound elastography.ResultsThe shear moduli of the VM, VL and RF in the control group did not significantly interact, while the shear moduli in the patient group did show a significant interaction. In the resting condition, there was no difference between the unaffected and affected sides in the patient group, but the shear moduli of the VM and VL in the contraction condition was significantly lower on the affected side than the unaffected side.The contraction ratios between muscles by limbs did not significantly interact. However, there were main effects due to muscle and limb factors. The VM and VL had a significantly higher contraction ratio than the RF, and the control and unaffected limbs had a higher contraction ratio than the affected limb.ConclusionThe results demonstrated a decrease in muscle stiffness during contraction in patients with quadriceps femoris dysfunction. Measurement of the shear modulus has potential as a new evaluation index and with high sensitivity to decreases in muscle contraction.

DETERMINATION OF WIND SHEAR AND TURBULENCE INTENSITY ACCORDING TO YAK42-D “ROSHYDROMET” RESEARCH AIRCRAFT DATA

2021 ◽  
pp. 117-129
Author(s):  
V. V. VOLKOV ◽  
◽  
M. A. STRUNIN ◽  
A. M. STRUNIN ◽  
◽  
...  
Keyword(s):  
Boundary Layer ◽  
Wind Speed ◽  
Wind Shear ◽  
Vertical Shear ◽  
Horizontal Shear ◽  
S 100 ◽  
Research Aircraft ◽  
The Difference ◽  
Wind Shears ◽  
Aircraft Data

The results of the development and comparative analysis of methods for determining wind shear in the atmosphere (regression and difference ones) based on research aircraft data are presented. It is shown that shear calculation by the regression method gives the error of 0.002-0.006 (m/s)/km (depending on the length of the measurement sections) for horizontal shears and 0.04-0.12 (m/s)/100 m for vertical shears; the respective error of the difference method is 0.007 (m/s)/km and 0.07 (m/s)/100 m. Based on the Yak-42D “Roshydromet” research aircraft data, the values of shears of two horizontal components of wind speed in three directions (two horizontal and vertical) were calculated. According to the data of two research aircraft flights, the maximum values of the horizontal shear of wind speed components were reached above the boundary layer and were equal to 0.2 (m/s)/km, and the vertical shear was 1.2 (m/s)/100 m. The energy profiles of horizontal and vertical turbulent pulsations are constructed, it is shown that intense turbulence smooths wind shears in the convective atmospheric boundary layer.

Comparative study of destructive, nondestructive, and numerical procedures for the determination of moisture dependent shear moduli in Scots pine wood

2021 ◽  
Vol 63 (11) ◽  
pp. 1063-1069
Author(s):  
Murat Aydın ◽  
Hasan Hüseyin Ciritcioğlu
Keyword(s):  
Finite Element ◽  
Relative Humidity ◽  
Shear Modulus ◽  
Scots Pine ◽  
Constant Temperature ◽  
Transverse Wave ◽  
Element Analysis ◽  
Shear Moduli ◽  
Principal Axes ◽  
Static Shear

Abstract In this study, moisture dependent shear moduli in Scots pine (Pinus sylvestris L.) wood were determined by a 45° off-axis (longitudinal, radial, and tangential) compression test and ultrasonic transverse wave propagation. Finite element modeling was performed to ascertain how the results agree with the numerical method. Ultrasonic transverse wave velocities on the LR, LT, and RT planes were decreased from 1347, 1323, and 589 m × s-1 to 1286, 1269, and 561 m × s-1 when relative humidity increased from 45 % to 85 % at a constant temperature of 20 ± 1 °C, respectively. The dynamic and static shear modulus on the LR, LT, and RT planes were decreased from 988, 953, and 189, and 966, 914, and 182 MPa to 927, 903, and 176, and 845, 784, and 154 MPa when relative humidity increased from 45 % to 85 % at a constant temperature of 20 ± 1 °C, respectively. Therefore, both velocity and modulus values at all principal axes and planes were decreased with an increase in moisture. Maximum (15.2 %) and minimum (2.3 %) differences between dynamic and the static shear modulus were observed for GLT at 85 % and GLR at 45 % relative humidity, respectively. Coefficients of determinations between the dynamic and static shear moduli were ranged from 0.68 (GLR at 65 % RH) to 0.97 (GLR at 85 % RH). Finite element analysis, only for 65 % RH values, was performed using Solid 45 element, and, according to results, load-deformation curves created by linear orthotropic material properties, are well-matched with the static curves.

scholarly journals Predictions of the shear modulus of cheese, a soft matter approach

2019 ◽  
Vol 29 (1) ◽  
pp. 58-68 ◽  
Author(s):  
Graeme Gillies
Keyword(s):  
Shear Modulus ◽  
Soft Matter ◽  
Volume Fraction ◽  
Quantitative Model ◽  
Nano Particles ◽  
Core Shell ◽  
Two Dimensional ◽  
Shear Moduli ◽  
Numerical Predictions ◽  
The Many

Abstract The rheological and structural properties of cheese govern many physical processes associated with cheese such as slumping, slicing and melting. To date there is no quantitative model that predicts shear modulus, viscosity or any other rheological property across the entire range of cheeses; only empirical fits that interpolate existing data. A lack of a comprehensive model is in part due to the many variables that can affect rheology such as salt, pH, calcium levels, protein to moisture ratio, age and temperature. By modelling the casein matrix as a series core-shell nano particles assembled from calcium and protein these variables can be reduced onto a simpler two-dimensional format consisting of attraction and equivalent hard sphere volume fraction. Approximating the interaction between core-shell nano particles with a Mie potential enables numerical predictions of shear moduli. More qualitatively, this two-dimensional picture can be applied quite broadly and captures the viscoelastic behaviour of soft and hard cheeses as well as their melting phenomena.

Scaling properties of the shear modulus of polyelectrolyte complex coacervates: a time-pH superposition principle

2015 ◽  
Vol 17 (35) ◽  
pp. 22552-22556 ◽  
Author(s):  
M. Tekaat ◽  
D. Bütergerds ◽  
M. Schönhoff ◽  
A. Fery ◽  
C. Cramer
Keyword(s):  
Shear Modulus ◽  
Polyelectrolyte Complex ◽  
Superposition Principle ◽  
Scaling Properties ◽  
Shear Moduli ◽  
Complex Shear

A novel time-pH superposition principle describes the complex shear moduli in polyelectrolyte complex coacervates.

Integrity Assessment of Subsea Pipeline Dent / Buckle Using ILI Data

2019 ◽  
Author(s):  
Gurumurthy Kagita ◽  
Gudimella G. S. Achary ◽  
Mahesh B. Addala ◽  
Balaji Srinivasan ◽  
Penchala S. K. Pottem ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Failure Modes ◽  
Structural Integrity ◽  
Mechanical Damage ◽  
Metal Loss ◽  
Stress Concentrations ◽  
Subsea Pipeline ◽  
Integrity Assessment ◽  
Finite Element Software

Abstract Mechanical damage in subsea pipelines in the form of local dents / buckles due to excessive bending deformation may severely threaten their structural integrity. A dent / buckle has two significant effects on the pipeline integrity. Notably, residual stresses are set up as result of the plastic deformation and stress concentrations are created due to change in pipe geometry caused by the denting / buckling process. To assess the criticality of a dent / buckle, which often can be associated with strain induced flaws in the highly deformed metal, integrity assessment is required. The objective of this paper is to evaluate the severity of dent / buckle in a 48” subsea pipeline and to make the rerate, repair or replacement decision. This paper presents a Level 3 integrity assessment of a subsea pipeline dent / buckle with metal loss, reported in in-line inspection (ILI), in accordance with Fitness-For-Service Standard API 579-1/ASME FFS-1. In this paper, the deformation process that caused the damage (i.e. dent / buckle) with metal loss is numerically simulated using ILI data in order to determine the magnitude of permanent plastic strain developed and to evaluate the protection against potential failure modes. For numerical simulation, elastic-plastic finite element analyses (FEA) are performed considering the material as well as geometric non-linearity using general purpose finite element software ABAQUS/CAE 2017. Based on the numerical simulation results, the integrity assessment of dented / buckled subsea pipeline segment with metal loss has been performed to assess the fitness-for-service at the operating loads.

Analytical solutions of a spherical nanoinhomogeneity under far-field unidirectional loading based on Steigmann–Ogden surface model

2020 ◽  
Vol 25 (10) ◽  
pp. 1904-1923
Author(s):  
Youxue Ban ◽  
Changwen Mi
Keyword(s):  
Flexural Rigidity ◽  
Elastic Stiffness ◽  
Surface Model ◽  
Far Field ◽  
Stress Concentrations ◽  
Equilibrium Equations ◽  
Legendre Series ◽  
Simple Method ◽  
Shear Moduli ◽  
Special Cases

For a solid surface or interface that is subjected to transverse loading, the influence of its flexural resistibility to bending deformation becomes significant. A spherical inhomogeneity or void embedded in an infinite elastic medium under the application of nonhydrostatic loads represents a typical example. In this work, we consider the most fundamental loading of a far-field unidirectional tension. Analytical displacements and stresses are developed by the coupling of a Steigmann–Ogden surface mechanical model, the simple method of Boussinesq displacement potentials, the semi-inverse method of elasticity, and Legendre series representations of spherical harmonics. The problem is then solved by converting the equilibrium equations of displacement into a linear system with respect to the Legendre series coefficients. The developed solutions are general in the sense that they may reduce to their classical or Gurtin–Murdoch counterparts as special cases. Analytical expressions reveal that the derived solution depends on four dimensionless ratios from among surface material parameters, shear moduli ratio, and inhomogeneity or void radius. In particular, instead of depending on both flexural parameters in the moment–curvature relation, one fixed combination is sufficient to represent the surface flexural rigidity. This is in contrast with the influence of the in-plane elastic stiffness, in which both surface Lamé parameters matter. Parametric studies further demonstrate that, for metallic inhomogeneities or voids with radii between 10 nm and 100 nm, the effects of surface flexural rigidity on stress distributions and stress concentrations are significant.

scholarly journals The Off-Axis IBII Test for Composites

2020 ◽  
Author(s):  
S. Parry ◽  
L. Fletcher ◽  
F. Pierron
Keyword(s):  
Shear Modulus ◽  
Strain Rate ◽  
High Strain ◽  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Fibre Volume ◽  
Published Data ◽  
Shear Moduli ◽  
Test Methodology ◽  
Split Hopkinson

Abstract Composite components regularly experience dynamic loads in service. Despite this, it is still difficult to obtain accurate mechanical properties of composite materials under high strain rate conditions. In this study, a new application of the Image-Based Inertial Impact (IBII) test methodology was developed, to generate an accurate in-plane transverse and shear moduli dataset from unidirectional (UD) off-axis composite specimens. The obtained dataset was consistent across different sample configurations, where results from the UD45$$^{\circ }$$ ∘ off-axis specimens agreed well with the UD90$$^{\circ }$$ ∘ values. Validation of the shear modulus identification was also undertaken by comparing the results from the UD90$$^{\circ }$$ ∘ and UD45$$^{\circ }$$ ∘ specimens with a multi-directional (MD) configuration. Here, it was found that MD±45$$^{\circ }$$ ∘ specimen shear modulus values where marginally lower than that from the UD specimens, in accordance with the lower fibre volume fraction of the MD laminate. Low strain rate sensitivities in the $$0.5-2\times$$ 0.5 - 2 × 10$$^{3}$$ 3  $$\hbox {s}^{-1}$$ s - 1 regime evidenced in this work suggest previously published data (often from split-Hopkinson bar tests) may include both a material and system i.e. testing apparatus response.

Weak elastic anisotropy and the tube wave

Geophysics ◽  
1993 ◽  
Vol 58 (8) ◽  
pp. 1091-1098 ◽  
Author(s):  
Andrew N. Norris ◽  
Bikash K. Sinha
Keyword(s):  
Shear Modulus ◽  
Elastic Moduli ◽  
Wave Speed ◽  
Elastic Anisotropy ◽  
Transversely Isotropic ◽  
Anisotropic Formation ◽  
Inversion Procedure ◽  
Anisotropy Parameters ◽  
Tube Wave ◽  
Simple Inversion

Tube‐wave speed in the presence of a weakly anisotropic formation can be expressed in terms of an effective shear modulus for an equivalent isotropic formation. When combined with expressions for the speeds of the SH‐ and quasi‐SV‐waves along the borehole axis, a simple inversion procedure can be obtained to determine three of the five elasticities of a transversely isotropic (TI) formation tilted at some known angle with respect to the borehole axis. Subsequently, a fourth combination of elastic moduli can be estimated from the expression for the qP‐wave speed along the borehole axis. The possibility of determining all five elasticities of a TI formation based on an assumed correlation between two anisotropy parameters is discussed.

Sign in / Sign up

Export Citation Format

Share Document