scholarly journals A CFD Analysis of Decommissioned Oil Platforms Jackets on the Brazilian Coast

CFD Letters ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 63-80
Author(s):  
Fernando Rodrigues Gonzalez ◽  
Roger Matsumoto Moreira
Keyword(s):  
Oil And Gas ◽  
Artificial Reef ◽  
Free Water ◽  
Point Of View ◽  
Brazilian Coast ◽  
Ansys Fluent ◽  
Oil Platforms ◽  
Offshore Oil And Gas ◽  
Volume Method ◽  
Offshore Oil

Every facility reaches the last phase in its life cycle, which is decommissioning. Since the last decade, this subject has been gaining importance in Brazil’s offshore oil and gas companies. For jacket type rigs, one of the methods widely applied after idling the production is the conversion of these structures into artificial reefs (ARs). There are several critical aspects for choosing the best strategy for cutting and sinking a platform jacket, ensuring the success of an AR from a biological point of view. One of them is the influence of marine currents and their fluid-structure interaction which, by maximizing local upwelling and back vortex effects, favours the growth of aggregated flora and fauna. This study consists in the application of computational fluid dynamics (CFD) techniques for studying the marine flow around a disassembled and sunk jacket in the seabed for the purpose of converting it into an artificial reef. An FVM (Finite Volume Method) from a commercial software (most recent version of ANSYS FLUENT®) is applied with the upwind scheme. A k-ε turbulence model on steady state is chosen. Field data about Brazilian coastal currents are collected and analysed from the amount of information available on a Brazilian Navy's meteoceanographic program. Next, different combinations of cutting and sinking a jacket are studied, always keeping a minimum 55m free water column. The objective is to verify where the formation of local upwelling regions - that is, where the vertical velocity component reaches values equal or greater than 10% of the magnitude of the free flow velocity - is more significant, without decreasing back eddy formation. It is observed that the dismemberment of the jacket with the positioning of its parts in an increasing height sequence in the direction of the prevailing current is favourable to generate local upwelling while tipping the structure at 90° to the prevailing current results in the most voluminous back eddy region.

Arctic Europe Between National Interests and Arctic Governance

2019 ◽  
pp. 117-131
Author(s):  
Igor Kochev ◽  
Wim Heijman
Keyword(s):  
Marine Mammals ◽  
Oil And Gas ◽  
Point Of View ◽  
The Arctic ◽  
National Interests ◽  
Economic Point ◽  
Oil And Gas Operations ◽  
Offshore Oil And Gas ◽  
Offshore Oil ◽  
The Eu

From an economic point of view, melting ice is making the Arctic ocean increasingly important for a number of countries – Arctic states as well as non-Arctic states. Also, the EU has clear interests in the area. This chapter provides a brief description of those interests and its implications on the EU's relationship with the Arctic partners. This note takes seven aspects of the EU-relations with the Arctic states into consideration (i.e., the institutional framework, the EU Arctic interests and policies, shipping, fishing, marine mammals, offshore oil and gas operations, and the EU's Arctic partners).

scholarly journals Oceanographic gradients and patterns in invertebrate assemblages on offshore oil platforms

2008 ◽  
Vol 65 (6) ◽  
pp. 851-861 ◽  
Author(s):  
Henry M. Page ◽  
Carolynn S. Culver ◽  
Jenifer E. Dugan ◽  
Brent Mardian
Keyword(s):  
Exotic Species ◽  
Oil And Gas ◽  
Function Analysis ◽  
Sea Anemones ◽  
Oil Platforms ◽  
Offshore Oil Platforms ◽  
Invertebrate Assemblages ◽  
Offshore Oil And Gas ◽  
Channel Patterns ◽  
Offshore Oil

Abstract Page, H. M., Culver, C. S., Dugan, J. E., and Mardian, B. 2008. Oceanographic gradients and patterns in invertebrate assemblages on offshore oil platforms. – ICES Journal of Marine Science, 65: 851–861. We explored variability in the composition and cover of subtidal macroinvertebrate assemblages, and the recruitment and growth rates of selected invertebrate species, on seven offshore oil and gas platforms arrayed across a gradient in oceanographic conditions in the Santa Barbara Channel, CA, USA. The major macroinvertebrate taxa (sea anemones, mussels, barnacles, tubiculous amphipods, hydroids, and sponges) were common to all platforms. However, discriminant function analysis (DFA) revealed that the assemblages of two platforms (Gilda and Gail) clearly differed from the other platforms, a pattern attributable, in part, to the presence of conspicuous exotic species (the anemone, Diadumene sp., and encrusting bryozoan, Watersipora subtorquata) on these platforms. If these exotic species were excluded from the analysis, platforms in proximity to each other generally tended to have invertebrate assemblages more similar to each other than to platforms located farther away. Spatial variation in barnacle recruitment onto ceramic plates and mussel growth rate reflected prevailing oceanographic gradients. The existence of along-channel patterns in the composition of platform invertebrate assemblages, and in invertebrate recruitment and growth associated with oceanographic gradients, suggests that assemblages attached to platforms or other artificial structures may be useful barometers of short and perhaps longer term change in ocean climate.

scholarly journals Benthic biodiversity on old platforms, young wind farms, and rocky reefs

2018 ◽  
Vol 77 (3) ◽  
pp. 1250-1265 ◽  
Author(s):  
Joop W P Coolen ◽  
Babeth van der Weide ◽  
Joël Cuperus ◽  
Maxime Blomberg ◽  
Godfried W N M Van Moorsel ◽  
...  
Keyword(s):  
Wind Farm ◽  
Oil And Gas ◽  
Steel Substrate ◽  
Artificial Reef ◽  
Wind Farms ◽  
Rocky Reefs ◽  
Psammechinus Miliaris ◽  
Natural Reef ◽  
Offshore Oil And Gas ◽  
Offshore Oil

Abstract The introduction of artificial hard substrates in an area dominated by a sandy seabed increases habitat available to epifouling organisms. To investigate this, samples were taken on old offshore oil and gas platforms, and data were compared with data of a young wind farm and a natural reef. Depth, sampling date, abundance of Mytilus edulis, Psammechinus miliaris, Metridium dianthus, and the presence of Tubulariidae and substrate (rock or steel) all correlated with species richness. Multivariate analysis showed a large overlap in communities on steel and rock and between the wind farm and platforms. The community changed over a gradient from deep rocks to shallow steel substrate, but no strong community differentiation was observed. Deep steel was more similar to natural rocks than shallow steel. When an artificial reef is intended to be colonized by communities similar to those on a natural reef, its structure should resemble a natural reef as much as possible.

scholarly journals The Memories of Our Future: The Memories of Maūi

2021 ◽  
Author(s):  
◽  
Shannon Lenihan
Keyword(s):  
New Zealand ◽  
Oil And Gas ◽  
Marine Species ◽  
Marine Ecology ◽  
Mammal Species ◽  
Cetacean Species ◽  
Narrative Design ◽  
Oil Platforms ◽  
Offshore Oil And Gas ◽  
Offshore Oil

<p>This thesis proposes a way to re-inhabit and transform the adverse identity of an old offshore oil and gas platform. Located 35 kilometers off the West Coast of Taranaki, New Zealand, the Māui A Platform (also known as MPA) is transformed in this thesis design investigation into an Environmental Centre, a living retreat for ‘children’ (in fact, for adults who will be encouraged in the design to see life through the eyes of children). The intention is to generate knowledge and awareness about the environment.  The Māui A and Māui B offshore oil and gas platforms are nearing the end of their economic lifespan. Globally, the current most common decommissioning method of oil platforms involves the use of explosives at the base of the jacket. The structure is then towed to shore and dismantled. The explosives leave scars not only on the landscape the platforms once inhabited; they critically damage the surrounding marine ecology, vast numbers of marine species. This is of severe concern for the marine life and ecosystems surrounding the Māui A & Māui B Platforms as they are located in an extremely sensitive marine area where over 30 percent of the world’s cetacean species inhabit or through which they frequently migrate. Only two of these marine mammal species are not listed as ‘species of concern’ in the New Zealand Threat Classification list.  The future of these platforms does not need to cause more adversity to the environment, but rather can regenerate it. By re-purposing rather than exploding and dismantling these structures, this thesis aims to propose a way to re-inhabit the Māui A Platform and transform it into an educational retreat that enables further awareness, reconciliation, restoration, and protection of marine systems, environment, and threatened marine species. This thesis explores opportunities to create a closed circuit system as a means of providing food, fresh water, water treatment and energy for the platform.  To achieve this regenerative solution in ways that will resonate with those who visit the Māui A Platform, this project enters the realm of the imagination. The imagination is fundamental to learning - hence the proposition that this design be framed as both mythological and experiential. Narrative design – story telling – is explored as a tool to connect sustainable awareness and consciousness as a means to help educate the beneficiaries of this world – our ‘children’. To encourage the adult visitors to fully recognise that the beneficiaries are indeed our children, the thesis investigation will design the new Environmental Centre through the eyes of the child. As a tool to enhance the historic narrative of the site and context, the design strategically frames traces of important or unnoticed elements or equipment of the Māui A Platform.  In order to be understood and engaged with by ‘children’, this project enters the realm of the imagination enabling the design to be both mythological and experiential.</p>

scholarly journals The Memories of Our Future: The Memories of Maūi

2021 ◽  
Author(s):  
◽  
Shannon Lenihan
Keyword(s):  
New Zealand ◽  
Oil And Gas ◽  
Marine Species ◽  
Marine Ecology ◽  
Mammal Species ◽  
Cetacean Species ◽  
Narrative Design ◽  
Oil Platforms ◽  
Offshore Oil And Gas ◽  
Offshore Oil

<p>This thesis proposes a way to re-inhabit and transform the adverse identity of an old offshore oil and gas platform. Located 35 kilometers off the West Coast of Taranaki, New Zealand, the Māui A Platform (also known as MPA) is transformed in this thesis design investigation into an Environmental Centre, a living retreat for ‘children’ (in fact, for adults who will be encouraged in the design to see life through the eyes of children). The intention is to generate knowledge and awareness about the environment.  The Māui A and Māui B offshore oil and gas platforms are nearing the end of their economic lifespan. Globally, the current most common decommissioning method of oil platforms involves the use of explosives at the base of the jacket. The structure is then towed to shore and dismantled. The explosives leave scars not only on the landscape the platforms once inhabited; they critically damage the surrounding marine ecology, vast numbers of marine species. This is of severe concern for the marine life and ecosystems surrounding the Māui A & Māui B Platforms as they are located in an extremely sensitive marine area where over 30 percent of the world’s cetacean species inhabit or through which they frequently migrate. Only two of these marine mammal species are not listed as ‘species of concern’ in the New Zealand Threat Classification list.  The future of these platforms does not need to cause more adversity to the environment, but rather can regenerate it. By re-purposing rather than exploding and dismantling these structures, this thesis aims to propose a way to re-inhabit the Māui A Platform and transform it into an educational retreat that enables further awareness, reconciliation, restoration, and protection of marine systems, environment, and threatened marine species. This thesis explores opportunities to create a closed circuit system as a means of providing food, fresh water, water treatment and energy for the platform.  To achieve this regenerative solution in ways that will resonate with those who visit the Māui A Platform, this project enters the realm of the imagination. The imagination is fundamental to learning - hence the proposition that this design be framed as both mythological and experiential. Narrative design – story telling – is explored as a tool to connect sustainable awareness and consciousness as a means to help educate the beneficiaries of this world – our ‘children’. To encourage the adult visitors to fully recognise that the beneficiaries are indeed our children, the thesis investigation will design the new Environmental Centre through the eyes of the child. As a tool to enhance the historic narrative of the site and context, the design strategically frames traces of important or unnoticed elements or equipment of the Māui A Platform.  In order to be understood and engaged with by ‘children’, this project enters the realm of the imagination enabling the design to be both mythological and experiential.</p>

Marine Life Assemblage Assessment at Oil & Gas Platform in the South China Sea Offshore Malaysia

2021 ◽  
Author(s):  
Mohd Izzat Mohd Thiyahuddin ◽  
Azam Abdul Rahman ◽  
Emily Hazelwood ◽  
Amberlea Sparks ◽  
Mark Benfield ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Artificial Reef ◽  
Complete Removal ◽  
Biological Data ◽  
Ex Situ ◽  
Biological Assessment ◽  
Marine Life ◽  
Offshore Oil And Gas ◽  
Offshore Oil

Abstract In Malaysia, numerous offshore oil and gas platforms are approaching the end of their operational lifespans and will soon be scheduled for decommissioning. Traditional decommissioning typically involves the complete removal of the platform from the seabed, consequently resulting in the destruction of the established marine life communities present on the structure. A Rigs-to-Reefs strategy provides an alternative to the complete removal of obsolete, non-productive offshore oil and gas platforms, by converting the platform into a permanent artificial reef by utilizing one of the following three methods: partial removal or topple-in-place (in-situ), or tow and place (ex-situ). In-situ reefing provides a means of conserving the marine communities found on the platform by decommissioning the platform jacket in place as an artificial reef. However, not all platforms are good candidates for a Rigs-to-Reef conversion. Thus, pre-decommissioning biological assessments should be undertaken to determine the most appropriate decommissioning strategy on a case-by-case basis. In this study, a biological assessment was developed to catalog the marine life assemblages present on two offshore oil and gas platforms in Malaysia using remotely operated vehicles. Given the limited amount of biological data available on the marine ecosystems found on Malaysia’s platforms, this data may be useful for minimizing adverse impacts of platform removal, while enhancing benefits to the marine environment.

USE OF OIL AND GAS PLATFORMS AS HABITAT IN LOUISIANA'S ARTIFICIAL REEF PROGRAM

1996 ◽  
Vol 36 (1) ◽  
pp. 681
Author(s):  
R. A. Kasprzak ◽  
W.S. Perret
Keyword(s):  
Oil And Gas ◽  
Artificial Reef ◽  
Oil And Gas Industry ◽  
The United States ◽  
Coast Guard ◽  
Private Industry ◽  
Marine Habitat ◽  
Low Profile ◽  
Offshore Oil And Gas ◽  
Offshore Oil

Louisiana's offshore oil and gas industry began in 1947 when the first well was drilled out of sight of land south of Terrebonne Parish. Today over 3,700 offshore oil and gas platforms have been installed, supplying 25 per cent of the United States' production of natural gas and 12.5 per cent of its oil. In addition to meeting the world's energy needs, these structures also form one of the world's most extensive defacto artificial reef systems. However, federal regulations require that these structures be removed within 1 year after the lease is terminated. Disposal of obsolete offshore oil and gas structures is not only a net financial liability for private industry but can be a public loss of productive marine habitat. In 1986 the Louisiana Fishing Enhancement Act was signed into law, in response to the National Fishing Enhancement Act, creating the Louisiana Artificial Reef Program. This program was designed to take advantage of fishing habitat opportunities offered by these obsolete platforms. Since the program's inception 22 reef sites, utilising the components (jackets and decks) of 58 obsolete platforms, have been created off Louisiana's coast. The use of obsolete oil and gas platforms in Louisiana has proved to be highly successful. Their large numbers, design, longevity, and stability have provided a number of advantages over the use of traditional artificial reef materials. The participating companies also save money by converting the structure into a reef rather than abandoning it onshore; these companies are required to donate a portion of the savings to the state to run the artificial reef program. One disadvantage, however, is that the large size of these platforms restricts the distance to shore where they can be sited. To achieve the minimum clearance of 16 m over a submerged structure, as required by the Coast Guard regulations, the platforms must be placed in waters deeper than 30 m. Waters of this depth are found between 22 km and 115 km from shore on Louisiana's gently sloping continental shelf, making them almost inaccessible to many anglers. Funds generated by the program, however, can be used to develop reefs closer to shore if alternative low profile materials are used. Due to high maintenance costs of both the structure and aids to navigation, the increased liability exposure and the undetermined cost of removing the structure once it becomes a hazard to public safety and navigation, leaving the structures standing in place has thus far proved not to be a viable option in Louisiana.

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