Borehole stresses created by downhole seismic sources

Geophysics ◽  
1991 ◽  
Vol 56 (7) ◽  
pp. 1055-1057 ◽  
Author(s):  
G. A. Winbow
Keyword(s):  
Shear Stress ◽  
Data Acquisition ◽  
Hoop Stress ◽  
Seismic Sources ◽  
Vsp Data ◽  
Acoustic Sources

This paper analyzes the stresses created by downhole acoustic sources used for crosshole or reverse VSP data acquisition. The pressures created by downhole sources may be as large as [Formula: see text] bars which cannot affect intact steel casing. However, such pressures might in principle either (A) crack the cement radially through excessive hoop stress [Formula: see text], or (B) loosen the cement from the casing through an excessive value of shear stress [Formula: see text].

scholarly journals Finite Element Analysis of Composite Repair for Damaged Steel Pipeline

Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 301
Author(s):  
Jiaqi Chen ◽  
Hao Wang ◽  
Milad Salemi ◽  
Perumalsamy N. Balaguru
Keyword(s):  
Finite Element ◽  
Shear Stress ◽  
Hoop Stress ◽  
Pipe Wall ◽  
Von Mises Stress ◽  
Repair System ◽  
Composite Repair ◽  
Steel Pipeline ◽  
Von Mises ◽  
Infill Material

Carbon fiber reinforced polymer (CFRP) matrix composite overwrap repair systems have been introduced and accepted as an alternative repair system for steel pipeline. This paper aimed to evaluate the mechanical behavior of damaged steel pipeline with CFRP repair using finite element (FE) analysis. Two different repair strategies, namely wrap repair and patch repair, were considered. The mechanical responses of pipeline with the composite repair system under the maximum allowable operating pressure (MAOP) was analyzed using the validated FE models. The design parameters of the CFRP repair system were analyzed, including patch/wrap size and thickness, defect size, interface bonding, and the material properties of the infill material. The results show that both the stress in the pipe wall and CFRP could be reduced by using a thicker CFRP. With the increase in patch size in the hoop direction, the maximum von Mises stress in the pipe wall generally decreased as the maximum hoop stress in the CFRP increased. The reinforcement of the CFRP repair system could be enhanced by using infill material with a higher elastic modulus. The CFRP patch tended to cause higher interface shear stress than CFRP wrap, but the shear stress could be reduced by using a thicker CFRP. Compared with the fully bonded condition, the frictional interface causes a decrease in hoop stress in the CFRP but an increase in von Mises stress in the steel. The study results indicate the feasibility of composite repair for damaged steel pipeline.

Numerical CFD / FSI Study of Teflon and Dacron for Use in the Femoral Artery Graft Procedure

2019 ◽  
Author(s):  
Sukwinder Sandhu ◽  
Kevin R. Anderson
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Femoral Artery ◽  
Hoop Stress ◽  
Fluid Structure Interaction ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Implant Materials ◽  
Artery Graft ◽  
Wall Shear

Abstract This paper presents Fluid Structure Interaction modeling of candidate implant materials used in the femoral artery graft medical procedure. Two candidate implant materials, namely Teflon and Dacron are considered and modeled using Computational Fluid Dynamics (CFD) and structural Finite Element Analysis (FEA) to obtain Fluid Structure Interaction (FSI) developed stresses within the candidate materials as a result of non-Newtonian blood flowing in a pulsatile unsteady fashion into the femoral artery implant tube. The pertinent findings for a pulsatile velocity maximum magnitude of 0.3 m/s and period of oscillation of 2.75 sec are as follows. For the biological tissue the wall shear stress is found to be 2.15 × 104 Pa, the hoop stress is found to be 1.6 × 104 Pa. For the Teflon implant material, the wall shear stress is found to be 1.177 × 104 Pa, the hoop stress is found to be 2.2 × 104 Pa. For the Dacron implant material the wall shear stress is found to by 3.9 × 104 Pa, the hoop stress is found to be 2.17 × 104 Pa. Based upon the analysis herein the PTFE material would be recommended.

Isolated Lymphatic Vessel Perfusion System Design for Independently Controlling Hoop Stress and Shear Stress

2012 ◽  
Author(s):  
Jeffrey A. Kornuta ◽  
J. Brandon Dixon
Keyword(s):  
Shear Stress ◽  
Particulate Matter ◽  
Chronic Disease ◽  
Lymphatic Vessel ◽  
Hoop Stress ◽  
Lymphatic System ◽  
The Body ◽  
Tissue Homeostasis ◽  
Perfusion System ◽  
Clinical Problems

Most tissues in the body are supported by the lymphatic system for a variety of functions, including the regulation of fluid balance, the removal of particulate matter from the interstitium, as well as the transport of fat from the intestine to the blood, among others. Lymphedema, a chronic disease characterized by an inability of the lymphatics to maintain tissue homeostasis and estimated to affect over 130 million people worldwide, can result in serious clinical problems for which there are very few beneficial cures or therapies [1]. However, despite the importance of lymphatics and the prevalence of lymphatic disease, very little is known about the particular mechanisms through which the lymphatics fulfill its primary functions.

Broad-band VSP data acquisition and analysis in complex structure area

2016 ◽  
Author(s):  
Cai Zhidong* ◽  
Guo Mingjie ◽  
Zhang Kun ◽  
Wang Yang ◽  
Wang Yanhua
Keyword(s):  
Data Acquisition ◽  
Complex Structure ◽  
Broad Band ◽  
Vsp Data

Borehole-Driven 3D Surface Seismic Data Processing Using DAS-VSP Data

2021 ◽  
Author(s):  
Gang Yu ◽  
Junjun Wu ◽  
Yuanzhong Chen ◽  
Ximing Wang
Keyword(s):  
Data Processing ◽  
Data Acquisition ◽  
Seismic Data ◽  
Field Data ◽  
Seismic Data Processing ◽  
3D Surface ◽  
Data Volume ◽  
Vsp Data ◽  
Seismic Data Acquisition ◽  
Anisotropy Parameters

Abstract A 3D surface seismic data acquisition project was conducted simultaneously with 3D DAS-VSP data acquisition in one well in Jilin Oilfield of Northen China. The 3D surface seismic data acquisition project covered an area of 75 km2, and one borehole (DS32-3) and an armoured optical cable with high temperature single mode fiber were used to acquire the 3D DAS-VSP data simultaneously when the crew was acquiring the 3D surface seismic data. The simultaneously acquired 3D DAS-VSP data were used to extract formation velocity, deconvolution operator, absorption, attenuation (Q value), anisotropy parameters (η, δ, ε) as wel as enhanced the surface seismic data processing including velocity model calibration and modification, static correction, deconvolution, demultiple processing, high frequency restoration, anisotropic migration, and Q-compensation or Q-migration. In this project, anisotropic migration, Q-migration was conducted with the anisotropy parameters (η, δ, ε) data volume and enhanced Q-field data volume obtained from the joint inversion of both the near surface 3D Q-field data volume from uphole data and the mid-deep layer Q-field data volume from all available VSP data in the 3D surface seismic surveey area. The anosotropic migration and Q-migration results show much sharper and focussed faults and and clearer subsutface structure.

Experimental Shear Stress Analysis of the Thin Walled Aluminum Hollow Shaft under Torsion

2013 ◽  
Vol 199 ◽  
pp. 303-308
Author(s):  
Riza Gürbüz ◽  
Mehmet Ali Donertas ◽  
Mehtap Yavuz
Keyword(s):  
Experimental Study ◽  
Shear Stress ◽  
Data Acquisition ◽  
Strain Gauge ◽  
Twist Angle ◽  
Shear Stresses ◽  
Shaft Length ◽  
Car Industry ◽  
Hollow Shaft ◽  
Applied Torque

In this experimental study, maximum torsion shear stresses occurring on the hallow aluminum shaft under various small torsion loads were measured with strain gauge, data acquisition cards and computer. Special software was developed to measure maximum strain and stress on the thin aluminum hollow shaft. Stress values occurring on the aluminum hallow shaft under various small loads were measured with strain gauge and those strain values were transmitted to computer directly with data acquisition cards. Using the strain, the load and other constant values of the material (Torsion stress, outside and inside diameters of shaft, length of shaft, shear stress modulus, applied torque loads, twist angle of shaft etc) the stress values occurring on the hallow shaft are calculated by computer program and the stress-strain graph is drawn on the computer screen automatically [Refer to table1 Fig. 2,3,4 ,5 and . In this experimental study, the theoretical knowledge given in the books and experiment results obtained under laboratory conditions were compared with each other. The obtained results were almost same. Similar experimental application could be used for real applications in car industry and mobile machines [.

Abstract P006: Purinergic Receptor Activation Protects Glomerular Microvasculature From Increased Mechanical Stress In Angiotensin Ii-induced Hypertension: A Modeling Study

Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Owen Richfield ◽  
Ricardo Cortez ◽  
Martha FRANCO ◽  
L Gabriel G NAVAR
Keyword(s):  
Blood Flow ◽  
Shear Stress ◽  
Angiotensin Ii ◽  
Hydraulic Conductivity ◽  
Purinergic Receptors ◽  
Hoop Stress ◽  
Ang Ii ◽  
Efferent Arteriole ◽  
Induced Hypertension ◽  
Purinergic Stimulation

Angiotensin II (Ang II)-induced hypertension increases afferent and efferent arteriole resistances via the actions of Ang II on the AT1 receptor. In addition to the increased interstitial levels of Ang II, the increased arterial pressure increases interstitial ATP concentrations which act on the purinergic receptors P2X1 and P2X7, to constrict the AA, preventing increases in plasma flow and single nephron GFR (SNGFR). Blockade of the P2 receptors also mitigates the effects of Ang II, thus increasing blood flow and SNGFR, but the resulting increases in mechanical stresses (shear stress and circumferential hoop stress) on the glomerular microvasculature have not been quantified. A mathematical microvascular hemodynamic glomerular model was developed to simulate blood flow and plasma filtration at each of 320 capillary segments in an anatomically-accurate rat glomerular capillary network topology. Afferent and efferent arteriole resistances and network hydraulic conductivity were adjusted to match glomerular hemodynamic data for control, Ang II-induced hypertension and P2X1-blocked conditions (Franco, Martha, et al. Amer. J. Physiology-Renal 313.1 (2017): F9-F19). Ang II infusion increased both afferent and efferent resistances, reducing blood flow while slightly raising glomerular pressure. Blockade of the purinergic receptors reduced both afferent and efferent resistances, maintaining glomerular pressure at hypertensive levels but increasing blood flow significantly, increasing shear stress from 24.9 dynes/cm 2 in hypertensive conditions to 71.3 dynes/cm 2 after purinergic blockade. Because glomerular pressure was maintained, hoop stress barely changed from 69.5 kPa in hypertensive conditions to 70.9 kPa after purinergic blockade. Purinergic blockade also increased hydraulic conductivity and filtering surface area, increasing SNGFR. In hypertension, purinergic stimulation does not prevent the transmission of increased arterial pressure to the glomerular capillaries to reduce capillary hoop stress. However, activation of the purinergic system protects the glomerular microvasculature from increases in shear stress caused by a marked increase in blood flow that would occur in the absence of purinergic stimulation.

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