Failure analysis of pipeline on-site manufacturing details

Author(s):  
Dmitry A. Neganov ◽  
◽  
Eugeny P. Studenov ◽  
Sergey V. Skorodumov ◽  
Oleg A. Kozyrev ◽  
...  

About 4 % of the connecting pieces used in the construction of oil pipelines in the 1950s–1970s were manufactured in the field. Despite the fact that in recent years the number of such parts has significantly reduced, failures associated with their lack of reliability occupy a noticeable share in the total number of failures in the system of oil trunk pipelines. The purpose of this work is to analyze the typical causes of failure of connecting parts using the example of a tee bend with a reinforcing plate. The authors carried out structural and fractographic studies of the defective structure. On the basis of information about the operating conditions and the actual characteristics of the bend metal, as well as data on the centers of destruction and the nature of crack propagation, computer modeling of the stress-strain state of the part was carried out. Based on the results of metallurgical studies and computer modeling, it was established that the cause of the formation of a through crack in the weld at the junction of the main oil pipeline and the reserve branch was excess stresses in the area of welding of the reinforcing plate to the branch, exceeding the tensile strength of the material of the tee branch pipe.

2011 ◽  
Vol 8 (1) ◽  
pp. 201-210
Author(s):  
R.M. Bogdanov

The problem of determining the repair sections of the main oil pipeline is solved, basing on the classification of images using distance functions and the clustering principle, The criteria characterizing the cluster are determined by certain given values, based on a comparison with which the defect is assigned to a given cluster, procedures for the redistribution of defects in cluster zones are provided, and the cluster zones parameters are being changed. Calculations are demonstrating the range of defect density variation depending on pipeline sections and the universal capabilities of linear objects configuration with arbitrary density, provided by cluster analysis.


2021 ◽  
Vol 137 (6) ◽  
pp. 54-56
Author(s):  
A. K. Nikolaev ◽  
◽  
E. S. Demenin ◽  
K. I. Plotnikova ◽  
◽  
...  

The use of anti-turbulent and depressant additives makes it possible to increase the efficiency of oil pipelines transporting high-viscosity oil. In this method, the principle of increasing the efficiency of transportation is based on reducing the hydraulic resistance and increasing the fluidity of oil. The work carried out a theoretical study of the existing types of anti-turbulent and depressant additives. This article presents an experimental study of the effect of the MR 1088 depressant additive on an oil sample from the Usa – Ukhta main oil pipeline.


Author(s):  
Y. V. Yakymiv ◽  
O. M. Bortnyak

Modern oil transportation systems are characterized by a complex hydraulic structure and geometric configuration, and often require the need for a permanent or periodic pumping or dumping part of the oil flow. The implementation of such transportation technology necessarily leads to changes in the operating conditions of oil pipelines and in accordance with the need to regulate the operation of oil pumping stations. Consequently, determining the patterns of the impact of the process of dumping the part of the oil on the energy parameters of the operation of oil transportation systems is an extremely important task.The influence of periodic dumping the part of oil on the energy efficiency of the operation of main oil pipelines was studied. The impact of volume of discharges on the consumption of power on pumping oil in the system of the main oil pipeline was analyzed. It has been found that with the increase the volume of discharges, the specific consumption of electricity for oil pumping decreases.Based on the carried research, the recommendations on the selection of reliable, safe and optimal pumping modes in terms of cost of electricity for the operation of oil pipelines "Druzhba" in the direction of Mozyr - Brody - Tukholsky pass with periodical partial oil dumping on LPDS "Brody".


Author(s):  
A. E. Gusarov ◽  
L. V. Sergeeva

The article is devoted to computer modeling of the process of possible damage to the pipelines of nuclear power plants that received local thinning of the walls.The geometric features of pipelines are essential not only for assessing the intensity of erosion and corrosion of a metal, but also for the final strength assessment, in particular, when calculating local thinning of the walls of pipelines. The accuracy of forecasts of the life of pipeline structures directly depends on the ability to evaluate the strength of pipeline elements that have received local thinning, especially if these elements themselves have a complex shape. Such elements include elbows, nozzles, adapters (transitions), shells. All of these elements are thin-walled structures of complex shape. Computer modeling of the process of crack formation and growth requires solving several problems. A review and critical analysis of the available experimental information on the growth rates of cracks in specific structural materials and in the environment that is characteristic of given operating conditions is required. An assessment of the crack growth rate is impossible without determining the stresses and strains in the shell structure of complex spatial geometry. The development of routine criteria for crack growth and their attachment to a stress-strain state calculation program is the next task. To solve these problems, a complex of three-dimensional finite element methodologies and programs based on the theory of thick shells has been created. The article presents some results of calculating the stress-strain state of adapters and the growth of cracks in them.


Author(s):  
Andrey V. Zakharchenko ◽  
◽  
Alexander E. Gonchar ◽  
Roman Y. Shestakov ◽  
Polina V. Pugacheva ◽  
...  

The procedure for action in cases of a threat or an accident at oil pipeline transport facilities is defined in the relevant plans for emergency spillage prevention and response – ESPR. The purpose of the article is to analyze the requirements of the legislation in the field of development and approval of ESPR. The specifics of ESRP development at trunk pipeline facilities in Russia are noted, the US experience in combating oil and oil products spillage is presented. The problematic issues in the development and approval of ESRP, relevant for the domestic system of main oil pipeline transport, have been considered. It was established that the Federal Law No. 207-FL, adopted in July 2020, fundamentally changed the outdated and required revision approach to the coordination and approval of ESRP. At the same time, further work is needed to create a regulatory framework that establishes requirements for ESRP, as well as to improve ESRP, taking into account modern methods of predicting accidents, identifying emergencies, risk-oriented approaches to planning measures to localize and eliminate accidents, the specifics of operating organizations.


Author(s):  
Rustam Z. Sunagatullin ◽  
◽  
Rinat M. Karimov ◽  
Radmir R. Tashbulatov ◽  
Boris N. Mastobaev ◽  
...  

The results of investigations of the main causes and the most significant factors of intensification of paraffin deposition in main oil pipelines are presented. A comprehensive analysis of the composition and properties of commercial oils and their sediments was carried out, according to which phase diagrams of equilibrium of oil dispersed systems were obtained using the example of commercial oils from Bashkir fields. Based on the phase diagrams, a curve of wax oil saturation was constructed, the analysis of which confirms that the existing thermobaric conditions during the operation of main oil pipelines do not allow transporting oil without the risk of waxing. It was noted a special influence of the value of the temperature gradient in the near-wall zone and the imbalance of the ratio of high-molecular oil components in commercial batches formed in the process of joint pumping on the intensity of waxing of sections of oil pipelines complicated by deposits, which was confirmed by statistical data on the frequency of pigging. The regularities obtained in this way are proposed to be used as an express method for predicting complications associated with intensive waxing of main oil pipelines. In order to quickly assess the risks of waxing of sections of main oil pipelines, an indicator is introduced that characterizes the ratio of the content of solid paraffins to the total content of resins and asphaltenes of oil, called the criterion of instability of a commercial oil batch.


2020 ◽  
Vol 30 ◽  
pp. 6-10
Author(s):  
A.A. Antonov ◽  
Yu.A. Yakovlev ◽  
G.G. Ammosov ◽  
Z.G. Kornilova

1989 ◽  
Vol 62 (4) ◽  
pp. 643-655
Author(s):  
Richard W. Tomlinson ◽  
Daniel F. Sheridan

Abstract The use of pulsed NMR analysis under proper operating conditions has proven to be useful for controlling various polymer compositions in the manufacture of EPDM. It can be used in determining the amount of oil incorporated into oil-extended EPDMs. At higher oil contents, the differences in EPDM properties will affect this test method, which will require a separate calibration curve for each type of polymer. It can be used to measure the propylene content of EPDM. Comparison data have shown that this technique is more accurate in predicting crystallinity or propylene content than the standard IR method within the propylene range of 22 to 41%. Pulsed NMR can also be used to predict uncured EPDM compound tensile strength and EPDM/PP compression-molded tensile strength. Since these properties are affected by the crystallinity of EPDM, of which percent ethylene is the major contributor, then tensile strength can be determined indirectly. Based on the tensile and SER correlation, it seems obvious that this technique is measuring the spin-spin relaxation times of the crystalline phase, whereas the ir method is only measuring propylene content.


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