scholarly journals Decommissioning Plans for Fixed Offshore Platforms: A Brief Revision

2021 ◽  
Vol 9 (3) ◽  
Author(s):  
Marcio Soares Pinheiro ◽  
Paulo Roberto Duailibe Monteiro
Keyword(s):  
North Sea ◽  
Rio De Janeiro ◽  
The State ◽  
Oil Field ◽  
Offshore Platforms ◽  
The North ◽  
Campos Basin ◽  
Heavy Lift ◽  
Long Time ◽  
The North Sea

Brazil began to explore its seas in the 60’s of the XX Century looking for petroleum. This journey began in the Northeast and the first oil field produced offshore was the Guaricema Field, in the State of Sergipe. During the 70’s, Petrobrás found oil in the Campos Basin, between the States of Espírito Santo and Rio de Janeiro, that became the most important oil province in Brazil until the discovery of the Pre-Salt province, in the Santos Basin. As these fields are producing for a long time, many of them are already completely depleted or their production is in way of to be not commercial anymore, and their facilities need to be decommissioned. This review of decommissioning practices of fixed offshore platforms carried out worldwide has focus on the removal of topside with special vessels designed for this purpose or with conventional methods (crane vessels + barge). It will show the benefits of using specialised heavy lift vessels to remove the topsides and move it to shore for dismantling / recycling / reuse / disposal. The cases for study were the successful decommissioning projects in the North Sea: Brent B/D, Valhall QP, Viking, Curlew, Eider A, Golden Eye and Leman, Iwaki-Oki, Halfweg Q1, Yme and Ninian North.

1300 Tons Grouted Integrity Support Installation Case Study

2020 ◽  
Author(s):  
Beatriz Alonso Castro ◽  
Roland Daly ◽  
Francisco Javier Becerro ◽  
Petter Vabø
Keyword(s):  
North Sea ◽  
Structural Integrity ◽  
High Strength ◽  
Regulatory Compliance ◽  
Lessons Learned ◽  
Oil Field ◽  
The North ◽  
Future Production ◽  
Heavy Lift ◽  
The North Sea

Abstract The North sea Yme oil field was discovered in 1987, production started in 1996 and ceased after 6 years when it was considered no longer profitable to operate. In 2007 a new development was approved, being Yme the first field re-opened in the Norwegian Continental Shelf. The concept selected was a MOPUStor: comprising a jack-up unit grouted to a subsea storage tank. Due to compromised structural integrity and lack of regulatory compliance that came to light shortly after installation, the platform was required to be removed [1]. The remaining riser caisson and the future 1050 t wellhead module required a support to allow the re-use of the facilities and tap the remaining oil reserves. The innovative tubular frame support was designed as a braced unit, secured to the existing MOPUstor leg receptacles and holding a grouted clamp larger than typical offshore clamps for which design guidance in ISO is available. The existing facilities had to be modified to receive the new structure and to guide it in place within the small clearances available. The aim of this paper is to describe the solutions developed to prepare and verify the substructure for installation; to predict the dynamic behavior of a subsea heavy lift operation with small clearances around existing assets (down to 150 mm); and to place large volume high strength grouted connections, exceeding the height and thickness values from any project ever done before. In order to avoid early age degradation of the grout, a 1 mm maximum relative movement requirement was the operation design philosophy. A reliable system to stabilize the caisson, which displacements were up to 150 mm, was developed to meet the criteria during grouting and curing. In the stabilizer system design, as well as the plan for contingencies with divers to restart grouting in the event of a breakdown, the lessons learned from latest wind turbine industry practices and from the first attempt to re-develop the field using grouted connections were incorporated. Currently the substructure is secured to provide the long term integrity of the structure the next 20 years of future production in the North Sea environment.

On the Installation Planning of a Self-Floating Offshore Platform

1979 ◽  
Vol 16 (03) ◽  
pp. 279-293
Author(s):  
Michael F. Metcalf ◽  
Michael W. Praught ◽  
Wayne O. MacDonell
Keyword(s):  
North Sea ◽  
State Of The Art ◽  
The State ◽  
Offshore Platform ◽  
Scale Model ◽  
Offshore Platforms ◽  
Analysis And Design ◽  
The North ◽  
Field Activity ◽  
The North Sea

This paper describes the installation planning for a major self-floating offshore platform that recently has been installed in the North Sea. Attention is given to the naval architectural aspects of the installation planning with particular emphasis on three phases: analysis and design, scale-model testing, and field activity preceding and during the actual installation operation. The paper describes the state-of-the-art in the installation planning of major self-floating offshore platforms of the kind being designed and built worldwide, and demonstrates the close coordination of many diverse disciplines in planning such installation operations.

Underreamed Footings Support Offshore Platforms In The North Sea

1973 ◽  
Author(s):  
Clarence J. Ehlers ◽  
William R. Bowles
Keyword(s):  
North Sea ◽  
Offshore Platforms ◽  
The North ◽  
The North Sea

Long-term dynamics of fouling communities found on offshore installations in the North Sea

2003 ◽  
Vol 83 (5) ◽  
pp. 897-901 ◽  
Author(s):  
P. Whomersley ◽  
G.B. Picken
Keyword(s):  
North Sea ◽  
Offshore Platforms ◽  
Fouling Communities ◽  
The North ◽  
Offshore Installations ◽  
Oil Export ◽  
The North Sea ◽  
Northern North Sea ◽  
Fouling Organisms

Inspection videos of four offshore platforms in the central and northern North Sea were used to study the development of fouling communities on clamps and guides of oil export risers over an 11-y period (1989–2000). Results from multivariate analyses (multi-dimensional scaling and analysis of similarities) indicated that distinct assemblages developed in different geographical locations. These differences were mainly due to the protracted development of theMetridium senile(Cnidaria: Actinaria) zone on the northern sector platforms. The vertical zonation of fouling organisms was similar on all installations, although the water depth at platform locations varied from 80 to 169 m, indicating that fouling organisms display a wide bathymetric tolerance. This study has highlighted the value of long-term data present in operational inspection videos for the study of fouling communities.

Benthic monitoring of oil and gas offshore platforms in the North Sea using environmental DNA metabarcoding

2020 ◽  
Author(s):  
Florian Mauffrey ◽  
Tristan Cordier ◽  
Laure Apothéloz‐Perret‐Gentil ◽  
Kristina Cermakova ◽  
Thomas Merzi ◽  
...  
Keyword(s):  
North Sea ◽  
Oil And Gas ◽  
Environmental Dna ◽  
Offshore Platforms ◽  
The North ◽  
Dna Metabarcoding ◽  
The North Sea

The Gjøa Semi: a North Sea project relevant for Western Australia

2011 ◽  
Vol 51 (1) ◽  
pp. 589
Author(s):  
Kristian Aas ◽  
Lars Bjørheim
Keyword(s):  
North Sea ◽  
Western Australia ◽  
Oil And Gas ◽  
Development Project ◽  
Conceptual Level ◽  
Field Development ◽  
The North ◽  
Heavy Lift ◽  
The North Sea ◽  
Field Location

Gjøa was the largest field development project in Norway in 2010. Gjøa was proven in 1989 and are now being developed together with nearby Vega satellites. The combined reserves are estiThe recent Gjøa field development in the North Sea has many features that are relevant for the oil and gas developments north of Western Australia. While the field location is not very similar to the north of Western Australia, the field development solution is very relevant. Several subsea clusters are tied back to a semi-submersible platform with export of gas and condensate via pipelines to shore. Other aspects to the project that are relevant to Western Australia are split location engineering between Norway and India, fabrication of the hull in Korea and subsequent heavy lift transport to the assembly yard, pre-installation of the mooring system, and tow to field with ocean going tug boats. The semi concept, which was used for the Gjøa development, is a mature technology with few technical challenges on a conceptual level. On the other hand the building of an oil and gas platform for A$2 billion has many challenges, both economical and technical, that have to be solved to have a successful project for both the client and the contractor.

GEOLOGY AND GEOPHYSICS IN THE DISCOVERY OF GIANT OIL FIELDS

1973 ◽  
Vol 13 (1) ◽  
pp. 3
Author(s):  
P. E Kent
Keyword(s):  
North Sea ◽  
Oil Field ◽  
Petroleum Exploration ◽  
The Arctic ◽  
Continental Margins ◽  
Lateral Plate ◽  
Vertical Movements ◽  
The North ◽  
The North Sea ◽  
Northern Alaska

The paper gives the case histories of discovery in three major oil field areas-Iran, northern Alaska and the North Sea. These areas differ in their regional features and in the consequent requirements for geological and geophysical investigation and delineation. In Iran the earlier discoveries were based entirely on surface geology; geophysics became important with the need for deep survey. In northern Alaska structures mapped at surface gave only minor shows. Seismic surveys following geological deductions on reservoir development led to discovery of the giant Prudhoe Bay field near the Arctic coast. In the North Sea, in the much more complex extension of Permian-Mesozoic basins already well known on land, location of structures has been entirely by seismic survey.There is no close relation between the new Global Tectonics and the location of major oil field belts. The factors controlling the latter are multiple and complex. Resolution of the relative importance of vertical (epeirogenic) displacement as against the effect of lateral plate movement is nevertheless critical, particularly in Alaska.There is at present a large unresolved discrepancy between the times at which some continental margins developed (North Atlantic, East and West Indian Ocean) and with the physical evidence of sea floor spreading. In the three areas quoted, breakdown of the continental margins by vertical movements started in the Permian (—280 million years), but spreading is dated as beginning only in the late Cretaceous (—70 million years). It is the earlier movements, unexplained by current global theories, which have most relevance for petroleum exploration.

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