Improving the method for assessment of bending stresses  in the wall of an underground pipeline

Sulhadi, Sulhadi; Firstov, A A

doi:10.31897/pmi.2022.64

Cited by 5 publications

(7 citation statements)

References 30 publications

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“…Figure 5 shows that, in the modes without additives, the value of A 1 (0) is in the region of 0, and the spread of its values is in the range from −0.5 to 1.5. The above indicates that, in the modes without additives, the value of A 1 (0) is constant for various pumping conditions, and if it differs from the indicated values in the modes with an additive, it is due to the influence of the additive [40][41][42].…”

Section: Resultsmentioning

confidence: 99%

Study of the Rheological Properties and Flow Process of High-Viscosity Oil Using Depressant Additives

Nikolaev,

Plotnikova

2023

Energies

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This article analyzes the dependence of the choice of the method of transportation of high-viscosity oil on the rheological characteristics of the oil in question. An analysis of existing rheological models of high-viscosity oil was carried out, and it was found that a number of models have certain features (model coefficients, their purpose, quantity) that affect the choice of a rheological model of oil. The dependences for determining the coefficient of dynamic viscosity when pumping high-viscosity oil with the addition of pour-point depressants were studied, and the dependence of the hydraulic resistance coefficient when depressants are added to the oil was obtained. A method for choosing a rational oil heating temperature and diluent concentration to achieve the maximum pipeline performance is substantiated.

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Section: Resultsmentioning

confidence: 99%

Study of the Rheological Properties and Flow Process of High-Viscosity Oil Using Depressant Additives

Nikolaev,

Plotnikova

2023

Energies

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“…The position of an underground pipeline during its operation is currently determined according to the data of in-line inspection [40,41]. The essence of this method is the launch of in-line inspection gauges into the pipeline, which measure the position of the pipeline underground and search for defects.…”

Section: Methodsmentioning

confidence: 99%

Improving the Method of Replacing the Defective Sections of Main Oil and Gas Pipelines Using Laser Scanning Data

2022

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During the operation of main pipelines, many defects occur in the body of the pipe and on its surface. The main method for eliminating such defects is cutting out the defective section and welding a new one in its place. The cutting process is complicated by the possible sharp displacement of the ends of the pipeline located on both sides of the cutting site, which is dangerous for the lives of workers and can lead to breakage of the cutting equipment. In addition, to weld a new section, it is necessary to center the ends of the pipeline until they reach the alignment position, for which heavy, difficult-to-transport pipelayers are used, which allow centering the ends of the pipeline only by lifting them. Ensuring the possibility of such centering often requires additional digging of the repaired pipeline. Moreover, due to the large dimensions of pipelayers, payment of permits for their transportation is required. In addition, before transportation, pipelayers require their disassembly and assembly before carrying out repair work, which entails additional time and labor costs. To solve the problems described in this article, a developed design of devices for fixing and centering the ends of the pipeline is proposed, which makes it possible to fix the ends of the pipeline from their sharp displacement, and also to center them before welding a new section. A mathematical model was developed to assess the centering forces, the resulting stresses in the pipeline wall and the reaction forces that arise in the hydraulic cylinders of devices when leaving the ends of the pipeline in their sharp displacement. The initial data for the developed model are the coefficients of the polynomial describing the position of the pipeline in the repair trench. To accurately assess the position of the pipeline, a method of its laser scanning is proposed, the result of which is a point cloud of the pipeline. As part of the study, a method was also developed for the obtaining of a polynomial equation describing the bending of its central axis from a pipeline point cloud. As a result of experimental studies, this method has demonstrated sufficient accuracy in determining the position of the pipeline in the repair trench. Thus, the developed repair method makes it possible to increase both the safety of the repair and the technological and economic efficiency of the process of replacing a defective section.

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“…The above is also confirmed by the presence of a significant amount of hydrogen (up to 0.1 wt. % or 1000 ppm) [11] in metal layers adjacent Energies 2023, 16, 5585 2 of 15 to the outer surface of the destroyed pipe, exceeding the concentration of hydrogen in layers near the inner surface by 2-4 times, which is proved by experiment as per [9]. According to the same authors [9,10], the negative effect of hydrogen dissolved in metal is also the reason for the failure of pipelines carrying sulphur-containing oil products.…”

Section: Introductionmentioning

confidence: 91%

“…Therefore, timely detection of the pipeline section where the pipe wall was hydrogenated is a possible method of failure prevention [13][14][15]. The above conclusion is valid for both compressed hydrogen pipelines, where local hydrogenation of the pipe wall cannot be excluded, e.g., due to plastic deformation caused by soil movement [16] and other bending stresses [17][18][19], and pipelines carrying natural gas and oil products [20][21][22]. At the same time, currently existing methods of detecting increased hydrogen content in metal structures, both by measuring its concentration directly or indirectly-based on the change in mechanical properties of the metal-are destructive, since both use specimens cut from the analysed structure for research.…”

Section: Introductionmentioning

confidence: 99%

Using the Magnetic Anisotropy Method to Determine Hydrogenated Sections of a Steel Pipeline

Bolobov

Latipov

Zhukov³

et al. 2023

Energies

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The paper deals with a non-destructive method of detecting hydrogenated sections of pipelines, which is based on variations of the level of mechanical stresses generated in the surface layers of the steel pipe material during its hydrogenation. The use of a magnetoanisotropic method based on the phenomenon of metal magnetoelastic anisotropy development, which consists in the variation of the magnetic properties of ferromagnetic materials in direction and magnitude under the influence of mechanical stresses, is proposed as a way to register that variation. Based on the results of tensile testing of carbon steel plates with measurement of the difference in principal mechanical stresses (DPMS) occurring in metal, as well as experiments on electrolytic hydrogenation of specimens with measurement of the DPMS signal, it was confirmed that when steel structures are saturated with hydrogen, tensile stresses are generated in the surface layers, the magnitude of which increases as the concentration of hydrogen increases in the metal. In this case, it is assumed that the indicated dependence between the hydrogen concentration in the metal and the stresses arising as a result of hydrogenation is linear. For the example of lamellar specimens made of pipe low-carbon steel, the possibility of using the magnetoanisotropic method for registering sections of underground pipelines with a high content of hydrogen is substantiated, which can become the basis for a method of diagnosing sections of pipelines with broken insulation for the possibility of their further operation. The scientific novelty of this article is the establishment of a relationship between the hydrogen content in the metal, the stresses that arise in this case, and the change in the magnetic properties of ferromagnetic materials, characterized by the magnitude of the DPMS signal. This study contributes to the understanding of the process of hydrogenation of metals, and may be useful in detecting and preventing damage to gas and oil pipelines caused by hydrogen embrittlement as a cause of stress corrosion.

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Improving the method for assessment of bending stresses in the wall of an underground pipeline

Cited by 5 publications

References 30 publications

Study of the Rheological Properties and Flow Process of High-Viscosity Oil Using Depressant Additives

Study of the Rheological Properties and Flow Process of High-Viscosity Oil Using Depressant Additives

Improving the Method of Replacing the Defective Sections of Main Oil and Gas Pipelines Using Laser Scanning Data

Using the Magnetic Anisotropy Method to Determine Hydrogenated Sections of a Steel Pipeline

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