Sirena Dotada truss spar design for East Central Gulf of Mexico

OCEANS 2009 ◽  
2009 ◽  
Author(s):  
C. Dunbar ◽  
J. Cotten ◽  
R. Hartsfield ◽  
D. Garcia ◽  
R. Vallejo
Keyword(s):  
Gulf Of Mexico ◽  
East Central ◽  
Truss Spar

scholarly journals Structural framework and fault analysis in the east-central Gulf of Mexico shelf: Implications for offshore CO2 storage

2020 ◽  
Vol 134 ◽  
pp. 104020 ◽  
Author(s):  
Jingyao Meng ◽  
Jack Pashin ◽  
Avinash Chandra ◽  
Liang Xue ◽  
Seyi Sholanke ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Co2 Storage ◽  
Fault Analysis ◽  
East Central ◽  
Structural Framework

The Effect of Mooring System and Sheared Currents on Vortex Induced Motions of Truss Spars

2003 ◽  
Author(s):  
Radboud R. T. van Dijk ◽  
Arjan Voogt ◽  
Paul Fourchy ◽  
Saadat Mirza
Keyword(s):  
Gulf Of Mexico ◽  
Mooring System ◽  
Test Results ◽  
Current Profile ◽  
Scaled Model ◽  
Production Platform ◽  
Helical Strakes ◽  
Truss Spar ◽  
Set Up ◽  
Program Show

Since 1996 Spars have been used as production platform in the Gulf of Mexico. Spar Vortex Induced Motions (VIM) in strong currents like the hurricane and loop currents are an important consideration for the design of the mooring system and risers. This is important for the extreme offsets as well as fatigue in risers and the mooring system. This paper compares the VIM behavior of a truss Spar in sheared currents, like the Hurricane current in the Gulf of Mexico, with tow test results. Experiments have been carried out on a scaled model in both a complete mooring system and in a towing set-up with a simplified horizontal mooring. The Spar model consists of a hard tank with removable helical strakes, a truss section and a square soft tank. The results of this model test program show that both the choice of the mooring system and current profile have a significant influence on the VIM response of the Spar. The paper discusses the results of this research and also addresses important issues and considerations for VIM model tests.

A Comparison of Radial Wellbay and Traditional Truss Spar Designs

2011 ◽  
Author(s):  
John Murray ◽  
Edmund Muehlner ◽  
Guibog Choi
Keyword(s):  
Gulf Of Mexico ◽  
Deep Water ◽  
Performance Comparison ◽  
The Arctic ◽  
Base Case ◽  
Mooring Lines ◽  
Production Platform ◽  
Truss Spar ◽  
Motion Performance ◽  
Made In

The Spar continues to be a popular drilling and production platform design for ultra-deep water. In recent years, developers have introduced a number of design variations such as the Arctic Spar, closed centerwell Spar, and long Spar. As the industry moves production into ultra-deep water, the escalation in drilling costs, particularly for deeper more complicated wells, prompts the need to look for new deepwater floater designs, including Spars. This paper introduces some new features to the Truss Spar, including a radial wellbay layout and an adjustable buoyancy centerwell device. This new Radial Wellbay Spar design is investigated and compared to the traditional Truss Spar for the same topside and riser weights and subjected to the same environments. The base case assumes a drilling and production platform with the performance comparison made in terms of hull weights and dimensions and hull motions for post-Katrina Gulf of Mexico conditions. In general, the Radial Wellbay Spar offers a smaller hull with fewer mooring lines for the same payload while maintaining the Spar’s low motion performance.

Chert Gravel and Neogene Drainage in East-Central Kansas

1997 ◽  
pp. 29-41
Author(s):  
James S. Aber
Keyword(s):  
Information System ◽  
Spatial Distribution ◽  
Geographic Information System ◽  
Gulf Of Mexico ◽  
Geographic Information ◽  
Alluvial Deposits ◽  
East Central ◽  
Gis Techniques ◽  
Stream Erosion

Eastern Kansas has an active geomorphic regime dominated by stream erosion, which is strongly influenced by bedrock structure. Alluvial deposits of chert gravel of presumed Neogene age are widespread and abundant on hill tops and high terraces throughout the region. Many of these gravels contain quartzite and other exotic pebbles derived from western sources. Geographic information system (GIS) techniques are used to document and analyze the spatial distribution of upland chert gravel deposits. On this basis, Neogene drainage routes may be recognized for the ancestral Arkansas, ancestral Verdigris, ancestral Neosho, and ancestral Marais des Cygnes. These drainages bore little resemblance in position or direction to the modern rivers. Stream captures, valley entrenchment, and wholesale inversion of topography led to the modern drainage systems. During entrenchment, streams have shifted systematically southward and eastward, possibly as a result of long-term and continuing crustal tilting (neotectonism) down toward the Gulf of Mexico.  

Numerical Prediction of Spar Motions Considering Top Tension Riser Stiffness

2004 ◽  
Author(s):  
Cheng-Yo Chen ◽  
Prahoro Nurtjahyo
Keyword(s):  
Gulf Of Mexico ◽  
Model Test ◽  
Pitch Angle ◽  
Motion Prediction ◽  
Test Results ◽  
Proposed Model ◽  
Comparison Results ◽  
Truss Spar ◽  
Righting Moment ◽  
Delta Model

Spar motions are often predicted without explicitly considering the stiffness effect of the buoyancy can of top tension risers (TTRs). This may result from the inability of most motion prediction programs to take this effect into consideration. The forces exerted by the TTR buoyancy can on the spar provide a net beneficial righting moment. Hence, neglecting the effect of TTR stiffness could produce excessive predicted spar motions, particularly maximum pitch angle. The derived spar configurations based on such predicted motions are likely to be conservative and not optimal. This paper proposes a simple “Linearized P-Delta” model to account for the effect of TTR stiffness on spar motions. The predicted motions using the proposed model are compared with the model test results for a production truss spar in the Gulf of Mexico. The comparison results indicate that the proposed model is quite rigorous and correlates reasonably well with the model test results.

Truss Spar Structural Design for West Africa Environment

2002 ◽  
Author(s):  
J. Wang ◽  
Y. H. Luo ◽  
R. Lu
Keyword(s):  
West Africa ◽  
Gulf Of Mexico ◽  
Structural Design ◽  
Oil And Gas ◽  
Extreme Wave ◽  
Oil And Gas Development ◽  
Structural Fatigue ◽  
Long Period ◽  
Truss Spar ◽  
Offshore Industry

As the Truss Spar gains greater recognition by the offshore industry, it is expected that more Truss Spars will be built for deepwater oil and gas development not only for the Gulf of Mexico, but also for offshore West Africa, Brazil, and other deepwater fields. The offshore West Africa environment is known to have long-period swells with period in excess of 20 seconds although its 100-year extreme wave height and wind speed are significantly lower than those for the Gulf of Mexico. The long-period swells present unique challenges for structural design of the Truss Spar. In particularly, heave motions and structural fatigue caused by the swells can be significant and must be addressed early in the design process. A comparative study between a Truss Spar and a Classic Spar on global motions is provided in this paper. Inplace strength and fatigue performance is investigated using a generic Truss Spar model for both the Gulf of Mexico and West Africa environments. Motion RAOs, loads, structural strength and fatigue results are presented to illustrate the findings.

Improving the Motions of a Semi by the Addition of Heave Plates

2008 ◽  
Author(s):  
Cheng-Yo Chen ◽  
Yun Ding ◽  
Trevor Mills ◽  
John Murray
Keyword(s):  
Gulf Of Mexico ◽  
Model Test ◽  
Cost Effective ◽  
Analytical Prediction ◽  
Test Results ◽  
Effective Manner ◽  
Truss Spar ◽  
Heave Plate ◽  
Motion Characteristics ◽  
Plate System

Similar to the manner in which heave plates provide a Truss Spar with low global motions, a heave plate system can be used to significantly mitigate the motions of a conventional semi-submersible. This paper will focus on the global performance of a conventional semi-submersible that has been properly configured with heave plates. The design case is a Gulf of Mexico deepwater environment similar to that for a Spar located in 5,600 feet of water. The system has eight top-tensioned risers (TTR) supported on the top of the semi hull with tensioners, a spread mooring and a 10,000-ton operating payload. Extensive global motion analyses and comprehensive model testing have been carried out to validate the in-place behavior of such a solution. This paper presents the validation results from the analytical prediction and the model test. A semi-submersible with properly configured heave plates can be used as a viable deepwater dry-tree floating solution in such harsh environments as in the Gulf of Mexico. Because of its superior motion characteristics, this solution is also more SCR friendly and can be a better wet-tree application as compared to conventional semi-submersibles. The analytical and model test results demonstrate that the excitation of a semi-submersible hull by wind, wave and current can be adequately mitigated by the proper placement and sizing of a heave plate system. The analysis and testing also indicates that to achieve suitable motions in a cost effective manner requires incorporating fabrication and installation issues into the heave plate system. The in-place behavior of this solution has been validated and thus proving the concept provides a viable cost effective dry-tree floating solution for deepwater developments.

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