Installation Model Tests of a Gulf of Mexico Compliant Tower

1989 ◽  
Author(s):  
G.M. Monopolis ◽  
M.A. Danaczko
Keyword(s):  
Gulf Of Mexico ◽  
Model Tests ◽  
Compliant Tower

Model Testing for Vortex Induced Motions of Spar Platforms

2004 ◽  
Author(s):  
Mehernosh Irani ◽  
Lyle Finn
Keyword(s):  
Gulf Of Mexico ◽  
Model Test ◽  
State Of The Art ◽  
Model Testing ◽  
Model Tests ◽  
The State ◽  
Test Results ◽  
Test Set ◽  
Vortex Induced Vibrations ◽  
Set Up

The state-of-the art in model testing for Vortex Induced Vibrations (VIV) of Spars is presented. Important issues related to Spar VIV model testing are highlighted. The parameters that need to be modeled including hull geometry, strake configuration, mass and mooring properties and, considerations of test set-up and instrumentation are discussed. Results are presented from model tests of an as-built Spar deployed in the Gulf of Mexico. It is shown that the model test results compare well with the VIV responses measured in the field.

Field Trial of Vortex-Induced Vibration Suppression Technology for Drilling Riser Buoyancy

2019 ◽  
Author(s):  
Phillip P. Kurts ◽  
Hayden Marcollo ◽  
Andrew A. Kilner ◽  
Daniel Johnstone ◽  
Andrew E. Potts ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Eddy Current ◽  
Field Trial ◽  
Field Trials ◽  
Model Tests ◽  
Scale Model ◽  
Base Case ◽  
Test Results ◽  
Hydrodynamic Parameters ◽  
Viv Suppression

Abstract Instrumented field trials of Longitudinally Grooved Suppression (LGS) VIV suppression buoyancy modules have been completed on deep water drilling risers in the Gulf of Mexico. The field trials were used to validate the performance of the technology, which had previously been evaluated using prototype scale model tests. The measured riser responses over two drilling campaigns spanning more than six months were compared with each other and the outputs of computational riser modeling to validate the hydrodynamic parameter set derived through scale model tests and provide validated assessments of the suppression technology performance. The measured response of drilling risers equipped with LGS buoyancy has been compared with a publicly available dataset for the VIV response of a conventionally buoyed riser, showing reduced VIV response in agreement with model test results. Measured flex joint angles, current profiles and riser accelerations were used to validate the hydrodynamic parameters used in numerical riser analysis. Using the validated hydrodynamic parameters, the VIV and drag suppression performance was demonstrated by comparison with the model predictions for risers equipped with conventional buoyancy modules. Eddy current occurrence statistics for a location in the Gulf of Mexico were used to calculate the expected annual operability performance for both configurations. For the base case parameters, 12 days of annual operability improvement was predicted when using LGS buoyancy modules. A sensitivity study determined the effect of varying analysis assumptions on the predicted operability improvements. Measured current data from 2014 was also used to determine the operability benefits which could be realized within a year in which severe eddy current activity occurred. The analysis performed serves to validate the previous laboratory tests as well as answer questions about the applicability of high Reynolds Number test results to VIV suppression devices in the field. The use of previously validated testing and analysis methods is shown to provide reliable estimates of suppression technology performance which are borne out by testing in the field. This paper presents the first published field trial of shaped buoyancy type VIV suppression, a group of technologies which have until now only been demonstrated using scale model tests and Computational Fluid Dynamics simulations.

Dynamic Response of the Baldpate Compliant Tower Platform to Major Hurricanes in Gulf of Mexico

2012 ◽  
Author(s):  
Ben C. Chang ◽  
Bor-Feng Peng ◽  
James Craig Edel ◽  
Joe Kallaby
Keyword(s):  
Dynamic Response ◽  
Gulf Of Mexico ◽  
Compliant Tower

Float Over Installation Method—Comprehensive Comparison Between Numerical and Model Test Results

2006 ◽  
Vol 128 (3) ◽  
pp. 256-262 ◽  
Author(s):  
Arcandra Tahar ◽  
John Halkyard ◽  
Atle Steen ◽  
Lyle Finn
Keyword(s):  
West Africa ◽  
Gulf Of Mexico ◽  
Model Test ◽  
Test Results ◽  
Sea State ◽  
Numerical Predictions ◽  
Single Piece ◽  
Heavy Lift ◽  
Compliant Tower ◽  
Comprehensive Comparison

Installing a large deck onto a platform, such as a spar, using the floatover method is gaining popularity. This is because the operational cost is much lower than other methods of installation, such as modular lifts or a single piece installation by a heavy lift barge. Deck integration can be performed on land, at quay side and will not depend on a heavy lift barge. A new concept for a floatover vessel has been developed for operations in the Gulf of Mexico and West Africa. In this application sea state conditions are essential factors that must be considered in the Gulf of Mexico, especially for transportation. In West Africa, swell conditions will govern floatover deck (FOD) installation. Based on these two different environmental conditions, Technip Offshore, Inc. developed the FOD installation concept using semi-submersible barge type vessels. A significant amount of development work and model testing has been done on this method in recent years on spar floatover. These tests have validated our numerical methods. Another test was conducted to investigate the feasibility of a deck float-over operation onto a compliant tower for a West Africa project. The project consists of a compliant tower supporting a 25,401metricton(28,000s.ton) integrated deck. This paper will describe comparisons between model test data and numerical predictions of the compliant tower floatover operation.

Float Over Installation Method: Numerical and Model Test Data

2004 ◽  
Author(s):  
Arcandra Tahar ◽  
John Halkyard ◽  
Atle Steen ◽  
Lyle Finn
Keyword(s):  
West Africa ◽  
Gulf Of Mexico ◽  
Test Data ◽  
Model Test ◽  
Sea State ◽  
Numerical Predictions ◽  
Offshore Engineering ◽  
Single Piece ◽  
Heavy Lift ◽  
Compliant Tower

Installing a large deck onto a platform, such as a spar, using the floatover method is gaining popularity. This is because the operational cost is much lower than other methods of installation, such as modular lifts or a single piece installation by a heavy lift barge. Deck integration can be performed on land, at quay side and will not depend on a heavy lift barge. A new concept for a floatover vessel has been developed for operations in the Gulf of Mexico and West Africa. In this application sea state conditions are essential factors that must be considered in the Gulf of Mexico, especially for transportation. In West Africa, swell conditions will govern floatover deck (FOD) installation. Based on these two different environmental conditions, Technip Offshore Engineering developed the FOD installation concept using semi-submersible barge type vessels. A significant amount of development work and model testing has been done on this method in recent years on spar floatover. These tests have validated our numerical methods. Another test was conducted to investigate the feasibility of a deck float-over operation onto a compliant tower for the Benguela Belize (BBT) project. The BBT project consists of a compliant tower supporting a 25,401 metric ton (28,000 s. ton) integrated deck. This paper will describe comparisons between model test data and numerical predictions of the compliant tower floatover operation.

Vortex-Induced Motion of a Monocolumn Platform: New Analysis and Comparative Study

2009 ◽  
Author(s):  
Rodolfo T. Gonc¸alves ◽  
Andre´ L. C. Fujarra ◽  
Guilherme F. Rosetti ◽  
Kazuo Nishimoto ◽  
Marcos Cueva ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Comparative Study ◽  
Numerical Models ◽  
Model Tests ◽  
Reliable Data ◽  
Experimental Tank ◽  
Data Set ◽  
Towing Tank ◽  
Comparison Of Results ◽  
Induced Motion

This paper presents a new analysis and a comparison of results obtained from Vortex-Induced Motion (VIM) model tests of the MonoGoM platform, a floating unit designed for the Gulf of Mexico. The choice of scale between the model and the platform in which the tests took place was a very important issue that took into account the basin dimensions and mooring design. The tests were performed in three different basins: the IPT Towing Tank in Brazil (September 2005), the NMRI Model Ship Experimental Towing Tank in Japan (March 2007) and the NMRI Experimental Tank in Japan (June 2008. The objective of this work is to discuss the most relevant issues regarding the concept, execution and procedures to analyze comparatively the results obtained from model tests. The approach employed in the tests was designed to build a reliable data set for comparison with theoretical and numerical models for VIM prediction, especially that of Monocolumn platforms.

Riser VIM Fatigue Design Induced by Deep Draft Semi-Submersible

2010 ◽  
Author(s):  
Sherry Xiang ◽  
Peimin Cao ◽  
Oriol Rijken ◽  
Jian Ma ◽  
Yongjun Chen
Keyword(s):  
Gulf Of Mexico ◽  
Transfer Functions ◽  
Sensitivity Study ◽  
Model Tests ◽  
Mooring Line ◽  
Simplified Approach ◽  
Fatigue Design ◽  
South Central ◽  
Four Square ◽  
The Impact

SBM Atlantia Inc. (SBMA) designs and constructs DeepDraft Semi® Floating Production Units (FPU). Two of these units are installed in the South-Central Gulf of Mexico at water depths of 8,000-ft and 6,000-ft. Both units are operational. Each of these FPUs is characterized by four square columns interconnected by four rectangular pontoons. Model tests and field measurements have indicated that these types of vessels are susceptible to Vortex Induced Motions (VIM). Typical loop/eddy current conditions at these Gulf of Mexico locations are likely to induce semi FPU VIM response. The paper addresses the impact of the semi-submersible FPU VIM motion on the fatigue design of the Steel Catenary Risers (SCR). Semi VIM induced riser fatigue design is performed using time domain approach and the scatter diagrams for the surface currents. Riser fatigue damage rates consider the effects of both the inline and transverse semi VIM responses. A comprehensive sensitivity study has been carried out, and the results demonstrate that riser VIM fatigue is primarily affected by the combination of column shape, current heading and intensity, the individual riser configuration, mooring line pretention and polyester stiffness. A simplified approach based on quasi-static Stress Transfer Functions (STF) is proposed. The STF is developed based on the VIM motion amplitude without considering the effect of the mean FPU offset induced by the current. The STF allows one to quickly develop a preliminary map identifying the feasible riser configurations. Such map can be used during the Front End Engineering Design (FEED) studies to initiate viable riser configurations. Finally, it is important to note that the preliminary field VIM measurements are significantly less than those observed during the model tests. Therefore, the fatigue life estimates based on the model test observations are considered to be conservative.

Octabuoy SDM: A Compact Semi-Submersible Design for Deepwater Applications

2005 ◽  
Author(s):  
Florus Korbijn ◽  
Ida Husem ◽  
Erik Pettersen
Keyword(s):  
West Africa ◽  
Gulf Of Mexico ◽  
Time Domain ◽  
Weight Ratio ◽  
Model Tests ◽  
Mooring System ◽  
Steel Catenary Risers ◽  
Loop Currents ◽  
Motion Characteristics ◽  
Theoretical Considerations

A new floater concept based on proven technology but combining this technology in a novel way has been designed for Deepwater operation in the Gulf of Mexico and other deepwater locations. The Octabuoy SDM (Shallow Draught, Mooring assisted) is a semi-submersible with a design and a tuned mooring system that ensure improved motion characteristics compared to other semi-submersibles. This makes the floater very well suited for accommodating Steel Catenary Risers (SCRs) in the Gulf of Mexico and dry tree solutions for West Africa. Motion results calculated for a typical Gulf of Mexico wave environment, using a coupled time domain approach are confirmed by extensive model testing of the concept, which proves the ability of the proposed concept to accommodate SCRs specifically for the Gulf of Mexico. Because of its relative shallow draught (23m) the platform is less susceptible to vortex induced motions (VIM) in loop currents compared to SPAR and other deep draught floaters. Theoretical considerations and model tests have proved the favorable platform behavior with respect to VIM. The Octabuoy SDM has a favorable topside load-to-hull weight ratio, which makes it a highly competitive solution compared to other semi-submersibles. Another advantage is that the platform may be outfitted and commissioned quayside.

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