Research Paper
Mechanical Engineering
Hadi eskandari; Moslem Ghanbari
Abstract
The present study deals on the geometry effects of the spherical pressure vessel(SPV) and the crack configuration on the variation of the stress intensity factor (SIF) through the crack line. The pressurized vessel is subjected to the pressure and thermal gradient (thermo-mechanical loading). The 3D ...
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The present study deals on the geometry effects of the spherical pressure vessel(SPV) and the crack configuration on the variation of the stress intensity factor (SIF) through the crack line. The pressurized vessel is subjected to the pressure and thermal gradient (thermo-mechanical loading). The 3D analysis of defected thick-walled pressurized sphere vessel is done using the numerical Finite Element Method (FEM). This work covers a wide range of the crack configurations in vessels with different geometries. The effect of the various parameters such as thermal gradient, RO/Ri, a/c and a/t on the variation of the dominant first mode of SIF through the crack front is studied. The obtained SIF’s are compared with the mechanical loading results (in the absence of the thermal gradient). The results show that parameters such as the aspect ratio of the crack, the ratio of the crack depth, the pressure vessel wall thickness and also the temperature gradient have significant effects on the distribution of the SIF through the crack line. It can be seen that the thermo-mechanical condition is more critical.
Research Paper
Petroleum Engineering – Drilling
Abbas Hashemizadeh; Mohammad Javad Ameri; Babak Aminshahidy; Mostafa Gholizadeh
Abstract
Stimulation of hydrocarbon wells with matrix acidizing operation is among the most common operations to stimulate the formation in order to remove the skin and improve the productivity index. But corrosion of equipment, including casings, is one of the most important concerns. In the present paper, the ...
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Stimulation of hydrocarbon wells with matrix acidizing operation is among the most common operations to stimulate the formation in order to remove the skin and improve the productivity index. But corrosion of equipment, including casings, is one of the most important concerns. In the present paper, the influence of the magnetic field on the corrosion behavior of drilling casing in 1.5 M (5 wt.%) HCl was investigated at various conditions using potentiodynamic polarization (PDP) and weight loss (WL) measurements. Taguchi’s design of experiment (L-18 array) should be utilized to model the impacts of magnetic field intensity, elapsed time, magnetization time, and temperature on the change in corrosion rate. The results of experiments show that passing of acid through a magnetic field reduces the corrosion rate of N-80 carbon steel in HCl up to 96%. Consequently, magnetized acid has a high ability to reduce the effects of corrosion on matrix acidizing operations as a green corrosion inhibitor.