ENSURE THE INTEGRITY OF OFFSHORE RISERS AT THE SPLASH ZONE AREA & OPTIMIZE THEIR EXTERNAL INSPECTION REGIME

2017 ◽  
Vol 21 (2) ◽  
pp. 250-260
Author(s):  
Mohamed Kotp ◽  
Waleed Hassan ◽  
Amr Mohamed ◽  
Ahmed Ahmed
Keyword(s):  
Splash Zone ◽  
Offshore Risers ◽  
External Inspection

Detection of Corrosion in Offshore Risers Using Guided Ultrasonic Waves

2007 ◽  
Author(s):  
Graham R. Edwards ◽  
Tat-Hean Gan
Keyword(s):  
Test Performance ◽  
State Of The Art ◽  
Development Programme ◽  
Guided Wave ◽  
Ultrasonic Waves ◽  
Splash Zone ◽  
Future Developments ◽  
Current State ◽  
Wide Range ◽  
Offshore Risers

Guided wave ultrasonics is now an established technology for detecting corrosion in pipes. The technique is principally applied to pipe that is insulated, buried or otherwise inaccessible to conventional NDT. TWI has experience in applying the technique to offshore risers, where there are specific problems. Access beneath the cut-off valves of the platform is restricted and the clamps used to hold the riser and the coatings used to protect it in the splash zone can affect test performance. This paper will describe these problems in detail and discuss ways of overcoming them. Case studies will be used to illustrate the current state-of-the-art and TWI’s research and development programme in long range ultrasonics for inspecting a wide range of components from pipes to railway lines will highlight future developments.

The Local Heat Balance in a Stationary Fluidized-Bed Furnace Burning Biomass Fuels

2003 ◽  
Author(s):  
Fredrik Niklasson ◽  
Filip Johnsson
Keyword(s):  
Fluidized Bed ◽  
Combustion Rate ◽  
Heat Balance ◽  
Circulating Fluidized Bed ◽  
Local Heat ◽  
Splash Zone ◽  
Two Phase ◽  
Bed Temperature ◽  
Temperature Constant ◽  
The Vertical Distribution

This work investigates the influence of biomass fuel properties on the local heat balance in a commercial-scale fluidized bed furnace. Experiments with different wood based fuels were performed in the Chalmers 12 MWth circulating fluidized bed boiler, temporarily modified to run under stationary conditions. A two-phase flow model of the bed and splash zone is applied, where the combustion rate in the bed is estimated by global kinetic expressions, limited by gas exchange between oxygen-rich bubbles and a fuel-rich emulsion phase. The outflow of bubbles from the bed is treated as “ghost bubbles” in the splash zone, where the combustion rate is determined from turbulent properties. It is found that a large amount of heat is required for the fuel and air to reach the temperature of the bed, in which the heat from combustion is limited by a low char content of the fuel. This implies that a substantial fraction of the heat from combustion of volatiles in the splash zone has to be transferred back to the bed to keep the bed temperature constant. It is concluded that the moisture content of the fuel does not considerably alter the vertical distribution of heat emitted, as long as the bed temperature is kept constant by means of flue gas recycling.

scholarly journals Study on the Temperature Dependence of Pitting Behaviour of AISI 4135 Steel in Marine Splash Zone

2015 ◽  
Vol 83 (7) ◽  
pp. 541-548 ◽  
Author(s):  
Yu XIUMING ◽  
Huang YANLIANG ◽  
Amar Prasad YADAV ◽  
Qu WENJUAN ◽  
Roland DE MARCO
Keyword(s):  
Temperature Dependence ◽  
Splash Zone

Experimental Wave Flume Tests in ROV-Wave Interaction Effects on the Line Tension for a Work Class ROV in Splash Zone

2021 ◽  
Author(s):  
Michael Binsar Lubis ◽  
Mehrdad Kimiaei
Keyword(s):  
Time History ◽  
Wave Interaction ◽  
Line Tension ◽  
Irregular Waves ◽  
Splash Zone ◽  
Remotely Operated Vehicle ◽  
Wave Flume ◽  
Flume Tests ◽  
Tension Time ◽  
Work Class

Abstract Integrity and stability of Remotely Operated Vehicle (ROV) when passing through the splash zone is one of the main concerns in the design of an ROV-umbilical system. Due to the lightweight nature of ROV in water, the umbilical experiences repetitive rapid transitions between slack and taut as the ROV travels through the splash zone. These rapid transitions induce tension spikes in the umbilical, namely snap forces, that can endanger the launch and recovery of an ROV. Therefore, it is important to ensure that the tension spikes do not exceed the safe working load of the umbilical. In this study, launch and recovery of a deep-water work class ROV are experimentally investigated using a 1:10 scaled ROV model through a series of wave flume tests. Different regular and irregular waves are generated in the flume while the ROV model is hung over the flume in four different positions. The tension time-history in the line is measured and recorded using a load cell at the top-end of the line. A simplified numerical model for launch and recovery of the ROV is developed and the numerical results are compared with the experimental ones. It is shown that the presented simplified model can be accurately used for analysis of launch and recovery of the ROV.

A Novel IoT-Based Method for Real-Time Detection of Spontaneous Leaks in Pipelines, Gathering Systems, and Offshore Risers

2021 ◽  
Author(s):  
Matthew Grimes ◽  
Nico Van Rensburg ◽  
Stuart Mitchell
Keyword(s):  
Signal Processing ◽  
Transmission Lines ◽  
Negative Pressure ◽  
Pressure Wave ◽  
Long Distance ◽  
Non Invasive ◽  
Long Distance Transmission ◽  
Offshore Production ◽  
Offshore Risers ◽  
Oil Gas

Abstract This paper presents on a non-invasive, IoT-based method for rapidly determining the presence and location of spontaneous leaks in pressurized lines transporting any type of product (e.g., oil, gas, water, etc.). Specific applications include long-distance transmission lines, gathering networks at well sites, and offshore production risers. The methodology combines proven negative pressure wave (NPW) sensing with advanced signal processing to minimize false positives and accurately identify the presence of small spontaneous leaks within seconds of their occurrence. In the case of long-distance transmission pipelines, the location of the leak can be localized to within 20-50 feet. The solution was commercialized in 2020 and has undergone extensive testing to verify its capabilities. It is currently in use by several operators, both onshore and offshore.

Anti-corrosive performance of epoxy coatings containing various nano-particles for splash zone applications

2017 ◽  
Vol 34 (8) ◽  
pp. 2301-2310 ◽  
Author(s):  
Mohammad Asif Alam ◽  
Ubair Abdus Samad ◽  
Rawaiz Khan ◽  
Manawwer Alam ◽  
Saeed Mohammed Al-Zahrani
Keyword(s):  
Nano Particles ◽  
Splash Zone ◽  
Epoxy Coatings

Force control of a load through the splash zone

2004 ◽  
Vol 37 (10) ◽  
pp. 227-232
Author(s):  
Bjørn Skaare ◽  
Olav Egeland
Keyword(s):  
Force Control ◽  
Splash Zone

scholarly journals Contribuição para o conhecimento da flora algológica marinha do estado do Paraná

1951 ◽  
Vol 2 (1) ◽  
pp. 125-138 ◽  
Author(s):  
Aylthon Brandão Joly
Keyword(s):  
Splash Zone ◽  
Hypnea Musciformis ◽  
Sargassum Cymosum ◽  
Gigartina Teedii

Esta nota é a primeira contribuição para a distribuição especial das algas marinhas do litoral paranaense (Caiobá). São considerados três tipos de litoral: a) Litoral rochoso sujeito à ação de arrebentação. b) Litoral rochoso mais ou menos abrigado. c) Manguesais. Dentro do esquema proposto, o primeiro tipo é subdividido em 2 zonas: 1.º) Zona dos borrifos, situada acima do limite médio da maré alta (fig. 2 n.º 1), correspondente à "Splash zone" ou à "Sprit zone" dos autores estrangeiros. 2.º) Zona de arrebentação (Ressaca), situada entre os níveis médios das marés baixa e alta, correspondendo à "Interdital zone" ou à "Gezeitenzone" dos autores estrangeiros, (fig. 2 n.º 2). A primeira zona só conta com uma alga, Lyngbya confervoides e pelo menos mais duas espécies de moluscos do gênero Littorina. A segunda zona, a mais rica tanto em algas como em animais, é essencialmente caracterizada em Caiobá pelas algas seguintes: Levringia sp. Chaetomorpha media e Centroceras clavulatum na parte mais alta, associadas a balanoides (craca) e a Mytilus perna (marisco). Mais abaixo domina Pterosiphonia pennata, Hypnea musciformis e Bryocladia thyrsigera. São apresentados também mais três tipos secundários dependendo das condições locais dos rochedos. Esta sucessão de Littorina, Balanus e Mytilus é a mesma existente no sul da África, segundo se depreende dos trabalhos de Stephenson (11,12) e de vários de seus colaboradores. O segundo tipo apresenta também duas zonas, sendo a segunda a mais rica e variada, aparecendo aqui como dominante, uma associação na qual, Callithamnion, Laurencia papulosa, Gigartina Teedii e Sargassum cymosum são as mais abundantes. É sugerida a existência de uma zona abaixo do limite inferior das marés baixas, zona essa representada por Rhodymenia Palmetta, Plocamium brasiliensis e Spatoglossum Schroederi pelo menos. É feita uma rápida enumeração das algas dos manguesais.

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