Numerical Trials for the Soil-Spudcan Interface of Self-Elevating Units

2020 ◽  
Author(s):  
F. Alegre ◽  
J. Logarzo ◽  
S. Alibakhshi ◽  
A. Achard
Keyword(s):  
Analytical Calculation ◽  
Offshore Structures ◽  
Rigid Bodies ◽  
Arbitrary Lagrangian Eulerian ◽  
Oil Platforms ◽  
Offshore Oil Platforms ◽  
Linear Behavior ◽  
Wide Range ◽  
Deformable Bodies ◽  
Offshore Oil

Abstract This paper describes the development of a numerical model of a jack-up leg supported on the seabed and the study performed in order to analyze the interaction at the interface between the soil and its spudcan. Self-elevating units or jack-ups are widely used for offshore operations and the strength of their whole structure is to be ensured for the environmental conditions encountered during the operations. This is why the determination of the soil-spudcan interface is a major challenge since it depends on a wide range of factors, such as sea conditions, properties of the soil, geometry and material of the structure, etc. In light of the unpredictable and non-linear behavior of the marine environment and the soil, it is necessary to develop further studies on this subject to reduce uncertainties and to ensure the safety of offshore structures, as most of the failures in the offshore oil platforms are related to foundations. To do so, different approaches have been used: • Abaqus/ Standard and Abaqus/Explicit solvers; • Rigid bodies and deformable bodies afterwards; • Three kind of meshes: ○ Lagrangian mesh; ○ Arbitrary Lagrangian - Eulerian mesh; ○ Coupled Eulerian - Lagrangian mesh. To validate the model and the results obtained numerically in the end of the project, a comparison with an analytical calculation of the spudcan penetration has to be performed, based on the geometry of the structure and the properties of the soil.

scholarly journals EXPERIENCE OF USING GNSS MEASUREMENT RESULTS AT IGS STATIONS FOR MONITORING OFFSHORE OIL PLATFORMS ON THE SAKHALIN ISLAND

2019 ◽  
Vol 1 (1) ◽  
pp. 62-70
Author(s):  
Alexey Davydov ◽  
Elena Gienko
Keyword(s):  
Sea Of Okhotsk ◽  
Oil And Gas ◽  
Offshore Structures ◽  
Reference Points ◽  
Labor Protection ◽  
Oil Platforms ◽  
Offshore Oil Platforms ◽  
Measurement Results ◽  
Marine Platform ◽  
Offshore Oil

The article contains a description of the methodology for geodetic monitoring of offshore structures, on the example of the PA-B oil and gas platform located on the northeast shelf of Sakha-lin Island in the Sea of Okhotsk. Monitoring of dangerous industrial assets is crucial for the safe op-eration of the facility, labor protection and environmental. The assessment of the possibility of GNSS monitoring of the stationary marine platform with respect to IGS stations without the use of the coastal network of reference points, while maintaining the accuracy of the coordinates at the centimeter level is performed in the article. The results of experiments on processing GNSS meas-urements with respect to the network of IGS stations using the AUSPOS service are presented. It is shown that this method provides a centimeter level of accuracy and concluded that it can be used for monitoring of marine stationary platforms.

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.

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.

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