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.

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.

CFD Simulation of Flow-Induced Motions of a Multi-Column Floating Platform

2011 ◽  
Author(s):  
Jang-Whan Kim ◽  
Allan Magee ◽  
Kenneth Yeoh Hock Guan
Keyword(s):  
Fluid Transport ◽  
Cross Validation ◽  
Cfd Simulation ◽  
Model Tests ◽  
Scale Model ◽  
Test Results ◽  
Floating Platform ◽  
Induced Motion ◽  
Rigid Body Motions ◽  
Floating Platforms

Recent improvements in capabilities of both hardware and software allow solving the coupled rigid body motions for the floating platform together with the fluid transport equations. This makes CFD a possible alternative or complement to model tests for predicting VIM performance. In addition, CFD allows simulating certain factors which cannot be addressed in scale model tests, and the two methods can ideally serve as cross-validation tools to bound the remaining uncertainties. Previous applications of CFD to Spar VIM predictions have shown promising results. Building on this, flow-induced motion simulations of multi-column floating platforms are being carried out using CFD as part of the R&D effort within Technip. The purpose of this paper is to present the results of two separate preliminary simulations applied to the prediction of vortex-induced motions of a TLP design and compare to the model test results.

scholarly journals Investigation of the Time Dependence of Wind-Induced Aeroelastic Response on a Scale Model of a High-Rise Building

2021 ◽  
Vol 11 (8) ◽  
pp. 3315
Author(s):  
Fabio Rizzo
Keyword(s):  
Wind Tunnel ◽  
Time Dependence ◽  
Wind Tunnel Test ◽  
Structural Response ◽  
Cumulative Distribution ◽  
Scale Model ◽  
Acquisition Time ◽  
Test Results ◽  
High Rise ◽  
High Rise Building

Experimental wind tunnel test results are affected by acquisition times because extreme pressure peak statistics depend on the length of acquisition records. This is also true for dynamic tests on aeroelastic models where the structural response of the scale model is affected by aerodynamic damping and by random vortex shedding. This paper investigates the acquisition time dependence of linear transformation through singular value decomposition (SVD) and its correlation with floor accelerometric signals acquired during wind tunnel aeroelastic testing of a scale model high-rise building. Particular attention was given to the variability of eigenvectors, singular values and the correlation coefficient for two wind angles and thirteen different wind velocities. The cumulative distribution function of empirical magnitudes was fitted with numerical cumulative density function (CDF). Kolmogorov–Smirnov test results are also discussed.

scholarly journals EXTREME WAVE PRESSURES AND LOADS ON A PILE-SUPPORTED WHARF DECK - INFLUENCES OF AIR GAP AND WAVE DIRECTION

2018 ◽  
pp. 5
Author(s):  
Andrew Cornett
Keyword(s):  
Offshore Structures ◽  
Model Tests ◽  
Scale Model ◽  
Extreme Waves ◽  
Wave Direction ◽  
Coastal Structures ◽  
Extreme Wave ◽  
Wave Impact ◽  
The Past ◽  
Water Depths

Many deck-on-pile structures are located in shallow water depths at elevations low enough to be inundated by large waves during intense storms or tsunami. Many researchers have studied wave-in-deck loads over the past decade using a variety of theoretical, experimental, and numerical methods. Wave-in-deck loads on various pile supported coastal structures such as jetties, piers, wharves and bridges have been studied by Tirindelli et al. (2003), Cuomo et al. (2007, 2009), Murali et al. (2009), and Meng et al. (2010). All these authors analyzed data from scale model tests to investigate the pressures and loads on beam and deck elements subject to wave impact under various conditions. Wavein- deck loads on fixed offshore structures have been studied by Murray et al. (1997), Finnigan et al. (1997), Bea et al. (1999, 2001), Baarholm et al. (2004, 2009), and Raaij et al. (2007). These authors have studied both simplified and realistic deck structures using a mixture of theoretical analysis and model tests. Other researchers, including Kendon et al. (2010), Schellin et al. (2009), Lande et al. (2011) and Wemmenhove et al. (2011) have demonstrated that various CFD methods can be used to simulate the interaction of extreme waves with both simple and more realistic deck structures, and predict wave-in-deck pressures and loads.

scholarly journals Experimental Investigation of the Mechanical Behavior of NC Linings in consideration of Voids and Lining Thinning

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Zude Ding ◽  
Jincheng Wen ◽  
Xiafei Ji ◽  
Zhihua Ren ◽  
Sen Zhang
Keyword(s):  
Mechanical Behavior ◽  
Local Deformation ◽  
Scale Model ◽  
Test Results ◽  
Load Bearing Capacity ◽  
Normal Concrete ◽  
Failure Characteristics ◽  
Defect Position ◽  
Deformation Properties ◽  
Combined Defects

The presence of voids or lining thinning directly affects the mechanical behavior of linings, and these defects threaten the safety of tunnel operation. In this study, a series of 1/5-scale model tests was used to investigate the mechanical behavior of normal concrete (NC) linings in consideration of voids and combined defects. Test results showed that the void and combined defects substantially reduced the load-bearing capacity and deformation properties of the linings. The inelastic mechanical behavior of the linings was also significantly affected by the defects. The effects of lining defects located at the spandrel were slightly weaker than those of lining defects located at the crown. As the void size or degree of combined defects increased, the tensile strain at the location of the lining defects also increased. Therefore, the defect position of the linings was easily damaged. The defects considerably reduced the overall deformation of the linings but increased the local deformation. The distribution of lining cracks was concentrated at the defect position. In addition, different failure characteristics of the lining were observed due to the differences in defects.

Large scale model tests on Royal Schelde SES

1989 ◽  
Author(s):  
R. DE GAAIJ ◽  
E. VAN RIETBERGEN ◽  
M. SLEGERS
Keyword(s):  
Large Scale ◽  
Model Tests ◽  
Scale Model ◽  
Large Scale Model

Consolidation of cement-treated sewage sludge using vertical drains

2005 ◽  
Vol 42 (2) ◽  
pp. 528-540 ◽  
Author(s):  
J Chu ◽  
M H Goi ◽  
T T Lim
Keyword(s):  
Sewage Sludge ◽  
Land Reclamation ◽  
Model Tests ◽  
Waste Materials ◽  
Test Results ◽  
Prefabricated Vertical Drains ◽  
Vertical Drains ◽  
Treated Sewage ◽  
The World

The disposal of sewage sludge and other waste materials has become a problem in many cities around the world. A study on the use of sewage sludge and other waste materials for land reclamation has been conducted. One of the methods studied is to dispose of the sludge after it has been mixed with binders or other waste materials and then to consolidate the mixture on site using surcharge and prefabricated vertical drains (PVDs). To study the consolidation behaviour of the sludge–binder mixtures around PVDs, model tests using a fully instrumented consolidation tank were conducted. Some of the test results are presented in this paper. The study shows that PVDs are effective in consolidating the sludge and binder mixtures, provided that the PVDs used can sustain large bending and resist corrosion by the chemicals in the sludge.Key words: consolidation, geoenvironmental, land reclamation, prefabricated vertical drains.

Development of a Stepped Line Tensioning Solution for Mitigating VIM Effects in Loop Eddy Currents for the Genesis Spar

2004 ◽  
Author(s):  
T. Kokkinis ◽  
R. E. Sandstro¨m ◽  
H. T. Jones ◽  
H. M. Thompson ◽  
W. L. Greiner
Keyword(s):  
Gulf Of Mexico ◽  
Eddy Current ◽  
Eddy Currents ◽  
Comprehensive Evaluation ◽  
Design Solution ◽  
Loop Current ◽  
Mooring Lines ◽  
Test Methodology ◽  
Induced Motion ◽  
High Reynolds

A number of spars are being installed in deepwater areas in the Gulf of Mexico (GoM), which are subject to loop / eddy current conditions and must be designed for Vortex-Induced Motion (VIM). This paper shows how recent advances in VIM prediction enabled an efficient and effective mooring design solution for the existing Genesis classic spar, which is installed in Green Canyon Block 205 in the GOM. The solution may also be applicable to new spar designs. During the Gulf of Mexico Millennium Eddy Current event in April 2001, the Genesis spar platform underwent vortex induced motions (VIM) which were greater than anticipated during the design of the mooring & riser systems. Analysis showed that if such large motions were to occur in higher currents in the range of the 100-year event, they could cause significant fatigue damage, and could lead to peak tensions in excess of design allowables. After a comprehensive evaluation of potential solutions, Stepped Line Tensioning (SLT) was determined to be the best approach for restoring the platform’s original mooring capacity on technical, cost and schedule grounds. SLT did not require extensive redesign of the existing mooring system of the spar. Furthermore, SLT provided a means to improve mooring integrity on an interim basis, while completing details for permanent implementation. Under SLT, the pretensions of the mooring lines are adjusted based on forecast currents in order to keep the platform below the VIM lock-in threshold at all times and for all eddy/loop current conditions up to and including the 100-year condition. High Reynolds number model tests conducted with a new test methodology were used to get a reliable prediction of the spar’s VIM response for this evaluation.

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