Thermal Vibration Compound Stress Relief on Thick DH36 Steel Welded Plates

2014 ◽  
Vol 576 ◽  
pp. 143-147 ◽  
Author(s):  
Shu Qi Li ◽  
Hong Yuan Fang ◽  
Xue Song Liu ◽  
Wei Cui
Keyword(s):  
Weld Line ◽  
Stress Relief ◽  
Thermal Vibration ◽  
Oil Platforms ◽  
Additional Heating ◽  
Offshore Oil Platforms ◽  
Before And After ◽  
Vibration Stress ◽  
Transverse Stresses ◽  
Offshore Oil

Stress relief on thick and large welded components is greatly needed in various applications, such as large oil transporting pipes and offshore oil platforms. Vibration stress relief (VSR) is an relatively new method for this purpose. The efficiency of this method is a key subject, especially when the components are extremely large and it is difficult to trigger sufficient vibration amplitude in the structures. In this study, additional heating on the area near the weld line was used to promote the efficiency of VSR. Both VSR and thermal-vibration compound stress relief (TVCSR) were used to 50mm thick DH 36 steel welded plates. The Longitudinal and transverse stresses near the weld lines before and after the treatments were investigated. Comparing to VSR, the TVCSR was more effective in decreasing the residual stress. Effects of additional heating was discussed.

Influence of Vibration Stress Relief (VSR) on the Residual Stress and Microstructure in Welded Plate of DH36 Low Alloy High Strength Steel

2014 ◽  
Vol 887-888 ◽  
pp. 924-928 ◽  
Author(s):  
Shu Qi Li ◽  
Hong Yuan Fang ◽  
Xuesong Liu
Keyword(s):  
Residual Stress ◽  
High Strength Steel ◽  
High Strength ◽  
Stress Relief ◽  
Steel Plates ◽  
Widespread Application ◽  
Oil Platforms ◽  
Offshore Oil Platforms ◽  
Transmission Electron ◽  
Vibration Stress

Welded components of DH36 low alloy high strength steel are widely used in offshore oil platforms and ships building. Stress reliving treatments to these welded components is of great importance. Vibration stress relief (VSR) method is an novel technology to release stress in welded components. In this study, 10×200×1000mm DH 36 steel plates were welded and then treated by VSR for about 1 hour. After the treatment, the residual stress was decreased by 29-72% at the welded toe, where the highest residual stress occurs. The metallographic microstructure of the joint was not changed by VSR. Investigation by transmission electron microscope (TEM) revealed that the amount of dislocations was increased at the welded toe. We hope this study can provide theoretical and practical fundamentals for widespread application of VSR on welded offshore engineering components.

Fouling assemblages on offshore oil platforms: diverse vertical reefs in the Arabian Gulf

2018 ◽  
Author(s):  
Pedro Range ◽  
Rodrigo Riera ◽  
Mustafa Omerspahic ◽  
Jessica Bouwmeester ◽  
Steffen Sanvig Bach ◽  
...  
Keyword(s):  
Arabian Gulf ◽  
Oil Platforms ◽  
Offshore Oil Platforms ◽  
Fouling Assemblages ◽  
Offshore Oil

Modelling of methane emissions from offshore oil platforms in the Norwegian sea

2021 ◽  
Author(s):  
Ignacio Pisso ◽  
Amy Foulds ◽  
Grant Allen
Keyword(s):  
Radiative Forcing ◽  
Oil And Gas ◽  
Lagrangian Model ◽  
Model Parameters ◽  
Positive Contribution ◽  
Atmospheric Methane ◽  
Norwegian Sea ◽  
Oil Platforms ◽  
Offshore Oil Platforms ◽  
Offshore Oil

<p>Methane is a major greenhouse gas that has increased since the pre-industrial era and reducing its emissions is potentially an effective way of mitigating the radiative forcing in the short term. The oil & gas industry has a positive contribution to the global atmospheric methane budget with fugitive emissions from infrastructure installations such as offshore oil platforms. As part of the United Nations Climate and Clean Air Coalition (UN CCAC) objective to quantify global CH4 emissions from oil and gas facilities, a series of aircraft campaigns have been carried out in the Norwegian sea among other areas. We report on the Lagrangian modelling activity of the emissions and transport sensitivities used to support the flux assessment. Source identification has been carried out based on backward modelling and has proved useful to interpret observations form the in situ airborne platforms. In addition, forward modelling of the emission plume in high resolution has been applied to constraining the plume height for mass balance methods assessment. Dependency of the resulting uncertainty of the flux estimates on various factors such as the choice of the meteorology and the of the Lagrangian model parameters is also discussed.</p>

Potential invasion of the Gulf of Mexico by Protemblemaria punctata (Teleostei: Chaenopsidae), a cryptobenthic fish endemic to Venezuela

2020 ◽  
Author(s):  
Jimmy Argüelles-Jiménez ◽  
Merari Contreras-Juarez ◽  
Eduardo Palacio Pérez
Keyword(s):  
Invasive Species ◽  
Gulf Of Mexico ◽  
Small Body ◽  
The Past ◽  
Oil Platforms ◽  
Offshore Oil Platforms ◽  
Viable Population ◽  
Body Sizes ◽  
The Caribbean ◽  
Offshore Oil

The movement of species to areas outside their native ranges has greatly intensified over the past few decades. However, detecting invasive species often requires detailed and regular surveys, especially for animals with small body sizes. A cryptobenthic fish endemic to the Caribbean coast of Venezuela, Protemblemaria punctata (Cervigón, 1966), is reported here from the southwestern Gulf of Mexico, based on the collection of 8 specimens (5 males and 3 females) from Bajo Mersey, a coral reef in the Parque Nacional Sistema Arrecifal Veracruzano (PNSAV). The collected specimens were taken from sessile worm tubes that grew on PVC structures previously placed on the reef at a depth of 6 m. The number of P. punctata specimens we collected could indicate that the species has established a viable population on the reefs in the PNSAV. The colonization of P. punctata in the Gulf of Mexico waters may be due to the dispersal of individuals present on offshore oil platforms that are transported from Trinidad to Venezuela and the Gulf of Mexico.

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