PSI - Issue 42

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ScienceDirect Structural Integrity Procedia 00 (2019) 000–000 Structural Integrity Procedia 00 (2019) 000–000

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

Procedia Structural Integrity 42 (2022) 351–355

© 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the 23 European Conference on Fracture – ECF23 © 2020 The Authors. Published by Elsevier B.V. This is an open access article under th CC BY-NC-ND license (http://creativ commons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of 23 European Conference on Fracture - ECF23 Keywords: turbine shaft; fatigue crack growth; xFEM; integrity 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of 23 European Conference on Fracture - ECF23 Keywords: turbine shaft; fatigue crack growth; xFEM; integrity 23 European Conference on Fracture - ECF23 Risk based assessment of corroded oil drilling rig pipe integrity and remaining life Snezana Kirin 1 , Aleksandar Sedmak 2 , Radzeya Zaidi 1 , Igor Martic 1 , Tamara Golubovic 1 23 European Conference on Fracture - ECF23 Risk based assessment of corroded oil drilling rig pipe integrity and remaining life Snezana Kirin 1 , Aleksandar Sedmak 2 , Radzeya Zaidi 1 , Igor Martic 1 , Tamara Golubovic 1 Abstract Risk based assessment of structural integrity of corroded oil drilling pipe is presented and applied on prototype (welded pressure vessel made of pipe) with artificial defects, which was previously investigated under service (10 MPa) and testing (22MPa) pressure. The new concept based on application of structural integrity estimation to assess risk level according to probability and consequence of failure was used. Probability of failure is taken as the ratio of the service point, estimated by using the basic linear elastic fracture mechanics concept, and point on limit line in the Failure Analysis Diagramme (FAD). Taking into account measure of probability and consequence, the risk matrix is made for the round defect in a new pipe, 1.75 mm (depth) x 26 mm (length), service and testing pressure. Results are also compared with the previous ones for defects 3.5 x 28 mm and 5.25 x 30 mm. These results are useful for managers to make decision about further use of damaged pipes, based on data provided by engineers. The procedure for risk assessment of structural integrity is a general one, applicable to any component with known geometry, including crack, material properties and loading data, as well as to the structural life assessment. a Innovation Center of Faculty of Mechanical Engineering, Kraljice Marije 16, 11120 Belgrade, Serbia b Faculty of Mechanical Engineering, University of Belgrade, Kraljice Marije 16, 11120 Belgrade, Serbia a Innovation Center of Faculty of Mechanical Engineering, Kraljice Marije 16, 11120 Belgrade, Serbia b Faculty of Mechanical Engineering, University of Belgrade, Kraljice Marije 16, 11120 Belgrade, Serbia Abstract Risk based assessment of structural integrity of corroded oil drilling pipe is presented and applied on prototype (welded pressure vessel made of pipe) with artificial defects, which was previously investigated under service (10 MPa) and testing (22MPa) pressure. The new concept based on application of structural integrity estimation to assess risk level according to probability and consequence of failure was used. Probability of failure is taken as the ratio of the service point, estimated by using the basic linear elastic fracture mechanics concept, and point on limit line in the Failure Analysis Diagramme (FAD). Taking into account measure of probability and consequence, the risk matrix is made for the round defect in a new pipe, 1.75 mm (depth) x 26 mm (length), service and testing pressure. Results are also compared with the previous ones for defects 3.5 x 28 mm and 5.25 x 30 mm. These results are useful for managers to make decision about further use of damaged pipes, based on data provided by engineers. The procedure for risk assessment of structural integrity is a general one, applicable to any component with known geometry, including crack, material properties and loading data, as well as to the structural life assessment. 1. Introduction Oil drilling rig pipes are subjected to a corrosive environment causing not only immanent failures, but also material degradation in form of reduced resistance to crack initiation and propagation, often leading to static or fatigue failure of rig pipes, or premature withdrawal from service, as described in number of cases, [1-10]. In this context it was actually necessary to analyse material resistance to cracking not only for new material, but also for material after certain period of exploitation. To fully comprehend the complex mechanism of corrosive action of fluids from oil and gas wells, all of the factors caused by the presence of carbon dioxide, hydrogen sulfide, chloride and mercury, affecting the initiation and development of corrosion should be taken into consideration. The main concern is the influence of CO 2 and H 2 S in the oil and gas exploitation facilities, because these gases, especially under high pressures and temperatures, create a corrosive environment [1]. Therefore, besides common reasons for failures of the pipelines, such as insufficient resistance to crack initiation and propagation and especially occasional inadequate quality of welded joints, corrosion defects often reduce strength and crack resistances, causing static or fatigue failure [3]. In order to fully comprehend the complex mechanism of corrosive action of fluids from oil and gas wells, all of the factors caused by the presence of carbon dioxide, hydrogen sulfide, chloride and mercury which affect the initiation and development of corrosion should be taken into consideration [5]. Figure 1 shows different corrosion phenomena in typical oil rig pipe [6]. 1. Introduction Oil drilling rig pipes are subjected to a corrosive environment causing not only immanent failures, but also material degradation in form of reduced resistance to crack initiation and propagation, often leading to static or fatigue failure of rig pipes, or premature withdrawal from service, as described in number of cases, [1-10]. In this context it was actually necessary to analyse material resistance to cracking not only for new material, but also for material after certain period of exploitation. To fully comprehend the complex mechanism of corrosive action of fluids from oil and gas wells, all of the factors caused by the presence of carbon dioxide, hydrogen sulfide, chloride and mercury, affecting the initiation and development of corrosion should be taken into consideration. The main concern is the influence of CO 2 and H 2 S in the oil and gas exploitation facilities, because these gases, especially under high pressures and temperatures, create a corrosive environment [1]. Therefore, besides common reasons for failures of the pipelines, such as insufficient resistance to crack initiation and propagation and especially occasional inadequate quality of welded joints, corrosion defects often reduce strength and crack resistances, causing static or fatigue failure [3]. In order to fully comprehend the complex mechanism of corrosive action of fluids from oil and gas wells, all of the factors caused by the presence of carbon dioxide, hydrogen sulfide, chloride and mercury which affect the initiation and development of corrosion should be taken into consideration [5]. Figure 1 shows different corrosion phenomena in typical oil rig pipe [6].

2452-3216 © 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the 23 European Conference on Fracture – ECF23 10.1016/j.prostr.2022.12.043 2452-3216 © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of 23 European Conference on Fracture - ECF23 2452-3216 © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of 23 European Conference on Fracture - ECF23