Pipeline Decommissioning: Comparative Study of Pipeline Corrosion in the North Sea and the Gulf of Thailand

2021 ◽  
Author(s):  
Jose Campins Bravo
Keyword(s):  
Carbon Steel ◽  
Corrosion Rate ◽  
North Sea ◽  
Marine Environment ◽  
Gulf Of Thailand ◽  
The North ◽  
The North Sea ◽  
The Gulf Of Thailand

Abstract The long-term degradation of decommissioned pipelines left in situ is an important topic in decommissioning projects. These constitute a long-term health and safety challenge in the form of snagging risk to other users of the sea. An accurate forecast of the long-term behavior of the pipelines in the marine environment would allow to make an informed decision regarding the feasibility of leave in place option for pipeline decommissioning. This paper aims to summarize the effect that individual environmental factors in marine corrosion have on the corrosion rate and to discuss in detail a chosen corrosion model that could be used to predict the long-term corrosion of in situ decommissioned subsea carbon steel pipelines in the marine environment. In addition, the long-term degradation will be predicted with the chosen corrosion model and the results will be compared for a range of subsea pipelines to be decommissioned in the North Sea and the Gulf of Thailand. With the chosen corrosion loss model, considering the higher average annual seabed temperature in the Gulf of Thailand in comparison with the North Sea, the predicted long-term corrosion rate of unprotected carbon steel is 0.053 mm/y for the North Sea and 0.069 mm/y for the Gulf of Thailand.

scholarly journals 4DEMON: Integrating 40 Years of Data on PCB and Metal Contamination in Marine Sediments of the Belgian Part of the North Sea

2021 ◽  
Vol 8 ◽  
Author(s):  
Hong Minh Le ◽  
Karen Bekaert ◽  
Ruth Lagring ◽  
Bart Ampe ◽  
Ann Ruttens ◽  
...  
Keyword(s):  
North Sea ◽  
Marine Environment ◽  
Historical Data ◽  
Anthropogenic Activities ◽  
Added Value ◽  
Mixed Effect ◽  
Broad Perspective ◽  
The North ◽  
The North Sea

The assessment of historical data is important to understand long-term changes in the marine environment. Whereas time series analyses based on monitoring data typically span one or two decades, this work aimed to integrate 40 years of monitoring and research data on polychlorinated biphenyls (PCBs) and metals in the Belgian Part of the North Sea (BPNS). Multiple challenges were encountered: sampling locations changed over time, different analytical methods were applied, different grain size fractions were analyzed, appropriate co-factors were not always analyzed, and measurement uncertainties were not always indicated. These issues hampered the use of readily available, highly standardized trend modeling approaches like those proposed by regional sea conventions such as OSPAR, named after the Oslo and Paris conventions.Therefore, we applied alternative approaches, allowing us to include most older historical data that have been obtained during the nineteen seventies and eighties. Our approach included reproducible and quality controlled procedures from data collection up to data assessment. It included spatial clustering, data normalization and parametric linear mixed effect modeling. A Ward hierarchical clustering was applied on recently obtained contaminant data, as the basis for a spatial division of the BPNS into five distinct areas with different contamination profiles. To minimize the risk of normalization errors for the metal data analyses, four normalization approaches were applied and mutually compared: granulometric and nickel (Ni) normalization, next to two hybrid normalization methods combining aluminum (Al) and iron (Fe) normalization. The long-term models revealed decreasing trends for most metals, except zinc (Zn) for which three out of four models showed increasing concentrations in all five zones of the BPNS. Offshore sediments contained the lowest normalized mercury (Hg) and cadmium (Cd) concentrations but high arsenic (As) concentrations. Trend analysis revealed a strong decrease in PCB concentrations in the nineteen eighties and nineties, followed by a slight increase over the last decade. The extended timeframe for contaminant assessment, as applied in this study, is of added value for scientists and policy makers, as the approach allows to detect trends and effects of anthropogenic activities within the marine environment within a broad perspective.

Marine fouling

1992 ◽  
Vol 100 ◽  
pp. 169-184 ◽  
Author(s):  
David Sell
Keyword(s):  
North Sea ◽  
Offshore Structures ◽  
Fouling Communities ◽  
Geographical Differences ◽  
The North ◽  
The North Sea ◽  
Fouling Organisms ◽  
Fouling Assemblages

SynopsisA comparison of macrofouling assemblages on offshore structures in the North Sea has revealed some similarity in their general characteristics, with a predominance in climax communities of relatively few species, such as the plumose anemone Metridium senile (L.) and the soft coral Alcyonium digitatum L., covering large proportions of the substratum. Specific geographical differences in community composition, diversity and successional development have been identified, however, and these are discussed in relation to environmental conditions and larval dispersal. In practical terms, the conservation of offshore fouling communities depends upon the fates of structures supporting these assemblages. Since the U.K.'s approach to platform decommissioning could ultimately involve the in situ toppling of structures in sea depths greater than 100 m, there would appear to be little threat to the long-term existence of offshore habitats for deep-water fouling assemblages. Moreover, an abundance of largely uninvestigated habitats for fouling organisms exists on submerged wrecks and other man-made structures. Thus, there appears to be no basis for a conservation requirement in relation to the fouling communities on fixed structures in the North Sea.

scholarly journals Long-term series in ichthyoplankton: sole and sprat at French coast of the North Sea from 1975 to 1994

1998 ◽  
Vol 21 (1) ◽  
pp. 113-121 ◽  
Author(s):  
Daniel Woehrling ◽  
Geneviève Le Fèvre-Lehoërff
Keyword(s):  
North Sea ◽  
The North ◽  
The North Sea

scholarly journals Observing and modelling phytoplankton community structure in the North Sea

2017 ◽  
Vol 14 (6) ◽  
pp. 1419-1444 ◽  
Author(s):  
David A. Ford ◽  
Johan van der Molen ◽  
Kieran Hyder ◽  
John Bacon ◽  
Rosa Barciela ◽  
...  
Keyword(s):  
Community Structure ◽  
North Sea ◽  
Phytoplankton Community ◽  
Marine Biodiversity ◽  
Phytoplankton Community Structure ◽  
Pigment Analysis ◽  
The North ◽  
The North Sea ◽  
In Situ Observations

Abstract. Phytoplankton form the base of the marine food chain, and knowledge of phytoplankton community structure is fundamental when assessing marine biodiversity. Policy makers and other users require information on marine biodiversity and other aspects of the marine environment for the North Sea, a highly productive European shelf sea. This information must come from a combination of observations and models, but currently the coastal ocean is greatly under-sampled for phytoplankton data, and outputs of phytoplankton community structure from models are therefore not yet frequently validated. This study presents a novel set of in situ observations of phytoplankton community structure for the North Sea using accessory pigment analysis. The observations allow a good understanding of the patterns of surface phytoplankton biomass and community structure in the North Sea for the observed months of August 2010 and 2011. Two physical–biogeochemical ocean models, the biogeochemical components of which are different variants of the widely used European Regional Seas Ecosystem Model (ERSEM), were then validated against these and other observations. Both models were a good match for sea surface temperature observations, and a reasonable match for remotely sensed ocean colour observations. However, the two models displayed very different phytoplankton community structures, with one better matching the in situ observations than the other. Nonetheless, both models shared some similarities with the observations in terms of spatial features and inter-annual variability. An initial comparison of the formulations and parameterizations of the two models suggests that diversity between the parameter settings of model phytoplankton functional types, along with formulations which promote a greater sensitivity to changes in light and nutrients, is key to capturing the observed phytoplankton community structure. These findings will help inform future model development, which should be coupled with detailed validation studies, in order to help facilitate the wider application of marine biogeochemical modelling to user and policy needs.

scholarly journals The ‘Yellow Danger’? Global forces and global fears in the North Sea and beyond (1600–1950)

2015 ◽  
Vol 27 (4) ◽  
pp. 743-754
Author(s):  
Matthias van Rossum
Keyword(s):  
Labour Market ◽  
North Sea ◽  
Labour Markets ◽  
Labour Relations ◽  
The North ◽  
15Th Century ◽  
Global Connections ◽  
The North Sea

Since direct shipping routes between Europe and Asia opened up at the end of the 15th century, the growing intercontinental and regional shipping connections resulted in increasing entanglements between European and Asian maritime labour markets. This article analyses the long term development of the connections between European and Asian maritime labour markets and its impact on socio-cultural (and labour) relations through three elements: first, the changing connections between European and Asian maritime labour markets; second, the changing nature of European and Asian maritime labour markets and its influence on the positions of sailors; and third, the changing relations between European and Asian sailors and its effects on the reactions and interactions in a globalising maritime labour market. It explores how these changing global connections shaped encounters between European and Asian sailors on (intercontinental) shipping in and from the North Sea region, and how it affected the positions and reactions of its workers.

The history and future of the North Sea benthos

1978 ◽  
Vol 76 (1-3) ◽  
pp. 193-200
Author(s):  
P. E. P. Norton
Keyword(s):  
North Sea ◽  
Bottom Type ◽  
The North ◽  
Late Tertiary ◽  
Long Term Changes ◽  
History Of ◽  
The North Sea ◽  
Temperature Depth

SynopsisThis is a brief review intended to supply bases for prediction of future changes in the North Sea Benthos. It surveys long-term changes which are affecting the benthos. Any prediction must take into account change in temperature, depth, bottom type, tidal patterns, current patterns and zoogeography of the sea and the history of these is briefly touched on from late Tertiary times up to the present. From a prediction of changes in the benthos, certain information concerning the pelagic and planktonic biota could also be derived.

scholarly journals Warm-water decapods and the trophic amplification of climate in the North Sea

2010 ◽  
Vol 6 (6) ◽  
pp. 773-776 ◽  
Author(s):  
J. A. Lindley ◽  
G. Beaugrand ◽  
C. Luczak ◽  
J.-M. Dewarumez ◽  
R. R. Kirby
Keyword(s):  
North Sea ◽  
Warm Water ◽  
Climate Signal ◽  
Southern North Sea ◽  
The North ◽  
Ecosystem Shift ◽  
The North Sea ◽  
Induced Changes ◽  
Water Species

A long-term time series of plankton and benthic records in the North Sea indicates an increase in decapods and a decline in their prey species that include bivalves and flatfish recruits. Here, we show that in the southern North Sea the proportion of decapods to bivalves doubled following a temperature-driven, abrupt ecosystem shift during the 1980s. Analysis of decapod larvae in the plankton reveals a greater presence and spatial extent of warm-water species where the increase in decapods is greatest. These changes paralleled the arrival of new species such as the warm-water swimming crab Polybius henslowii now found in the southern North Sea. We suggest that climate-induced changes among North Sea decapods have played an important role in the trophic amplification of a climate signal and in the development of the new North Sea dynamic regime.

‘In‐situ’ internal pipeline cleaning, heating and coating services in the North Sea

1987 ◽  
Vol 34 (2) ◽  
pp. 6-8
Author(s):  
P.J. Bryant ◽  
B.C. Goff ◽  
I.S. Lancaster
Keyword(s):  
North Sea ◽  
The North ◽  
The North Sea
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