Deepwater Riser

2021 ◽  
pp. 1-36
Author(s):  
Weiping Huang ◽  
Xuemin Wu ◽  
Juan Liu ◽  
Xinglan Bai
Keyword(s):  
Deepwater Riser

scholarly journals Prediction of deepwater riser VIV with an improved time domain model including non-linear structural behavior

2021 ◽  
Vol 236 ◽  
pp. 109508
Author(s):  
Sang Woo Kim ◽  
Svein Sævik ◽  
Jie Wu ◽  
Bernt Johan Leira
Keyword(s):  
Time Domain ◽  
Domain Model ◽  
Structural Behavior ◽  
Non Linear ◽  
Deepwater Riser

The Role of Offshore Monitoring in an Effective Deepwater Riser Integrity Management Program

2007 ◽  
Author(s):  
Brittany Goldsmith ◽  
Elizabeth Foyt ◽  
Madhu Hariharan
Keyword(s):  
Failure Modes ◽  
Human Life ◽  
Management Program ◽  
Measured Data ◽  
Operating Conditions ◽  
Environmental Damage ◽  
Positioning Systems ◽  
Integrity Management ◽  
Deepwater Riser

As offshore field developments move into deeper water, one of the greatest challenges is in designing riser systems capable of overcoming the added risks of more severe environments, complicated well requirements and uncertainty of operating conditions. The failure of a primary riser component could lead to unacceptable consequences, including environmental damage, lost production and possible injury or loss of human life. Identification of the risks facing riser systems and management of these risks are essential to ensure that riser systems operate without failure. Operators have recognized the importance of installing instrumentation such as global positioning systems (GPS), vessel motion measurement packages, wind and wave sensors and Acoustic Doppler Current Profiler (ADCP) units to monitor vessel motions and environmental conditions. Additionally, high precision monitoring equipment has been developed for capturing riser response. Measured data from these instruments allow an operator to determine when the limits of acceptable response, predicted by analysis or determined by physical limitations of the riser components, have been exceeded. Regular processing of measured data through automated routines ensures that integrity can be quickly assessed. This is particularly important following extreme events, such as a hurricane or loop current. High and medium alert levels are set for each parameter, based on design analysis and operating data. Measured data is compared with these alert levels, and when an alert level is reached, further response evaluation or inspection of the components in question is recommended. This paper will describe the role of offshore monitoring in an integrity management program and discuss the development of alert levels based on potential failure modes of the riser systems. The paper will further demonstrate how this process is key for an effective integrity management program for deepwater riser systems.

VIV Predictions for an SCR in Sheared Ocean Currents

2002 ◽  
Author(s):  
Christopher J. Wajnikonis
Keyword(s):  
Experimental Data ◽  
Design Parameters ◽  
Finite Element Analyses ◽  
Steel Catenary Riser ◽  
Specialized Software ◽  
Design Engineers ◽  
Sensitivity Studies ◽  
Deepwater Riser ◽  
Extended Program ◽  
Areas Of Interest

Vortex Induced Vibration (VIV) prediction is one of the key areas of interest in Deepwater Riser Engineering. Several Joint Industry Projects (JIPs) are currently in progress in this field, which results in an increase of experimental data available to design engineers, in revisions of specialized software and in development of new engineering tools. This paper presents VIV predictions for a hypothetical Steel Catenary Riser (SCR) using the latest versions of the SHEAR7 and the VIVA/VIVARRAY Programs. Both built-in and extended program capabilities are utilized and detailed plots of computation results are presented. Sensitivity studies on the influence of variations of selected design parameters are also included in the paper. Finite Element Analyses (FEAs) results and simple engineering tools were utilized in parallel to built-in program features. The calculations demonstrated, that for the riser investigated and presumably also for a wide variety of similar SCRs, that the built in program features are sufficient to predict VIVs conservatively. Notes on VIV predictions in a real ocean and on selected areas that require investigation are also included.

Assessment of Ultra Deepwater Riser Concepts for High-Motion Vessels

2014 ◽  
Author(s):  
Brian S. Royer ◽  
Thomas L. Power ◽  
Daniel O. Ayewah ◽  
William Head
Keyword(s):  
Deepwater Riser

The Evolution of Free Standing Risers

2009 ◽  
Author(s):  
Elizabeth Tellier ◽  
Ricky Thethi
Keyword(s):  
West Africa ◽  
System Architecture ◽  
Vertical Section ◽  
Single Line ◽  
Free Standing ◽  
Dynamic Motion ◽  
The Past ◽  
New Concepts ◽  
Complex Evaluation ◽  
Deepwater Riser

Deepwater riser selection is a complex evaluation of technical and commercial project drivers. The free standing hybrid riser (FSHR) has evolved in the last 10 years through major use in West Africa and is now gaining serious consideration in other deepwater provinces. The key benefit of the free standing riser is that the steel riser vertical section is offset from the vessel using flexible jumpers, thereby decoupling the riser from vessel dynamic motion. Early FSHR configuration took the hybrid bundle tower form. The very first free standing riser system, installed in 1988, consisted of the Placid hybrid bundle in the Gulf of Mexico. In the late nineties, a hybrid bundle tower was chosen for the Girassol development in West Africa. Since then, the industry has sanctioned numerous developments using multiple single line freestanding risers. Optimization of the FSHR is continuing with new concepts such as the Grouped SLOR developed to offer the combined benefits of both the bundle and single line multiple arrangements. This paper will describe how the FSHR configuration has evolved to meet increasing industry demands over the past 10 years and will discuss the future of this type of riser system. Increasing applications in ultra deepwater regions, hurricane prone locations and tiebacks to existing payload limited production vessels will be discussed with riser system architecture described including interfaces with the vessel and seabed.

Hydrodynamic Properties of an Asymmetric Deepwater Riser Bundle

2006 ◽  
Author(s):  
Charles Zimmermann ◽  
Richard James ◽  
Blaise Seguin ◽  
Mattias Lynch
Keyword(s):  
Cross Section ◽  
Water Depth ◽  
Hydrodynamic Characteristics ◽  
Cfd Analysis ◽  
Effective Solution ◽  
Hydrodynamic Properties ◽  
Global System ◽  
Field Development ◽  
Hydrodynamic Behaviour ◽  
Deepwater Riser

The BP operated Greater Plutonio field development offshore Angola comprises a spread-moored FPSO in 1,300 m water depth, serving as a hub processing the fluids produced from or injected into the subsea wells. The selected riser system is a riser tower tensioned by a steel buoyancy tank at its top end and distributed foam buoyancy along a central structural tubular. The riser bundle is asymmetric in cross-section and this paper presents the work performed to determine the specific hydrodynamic characteristics of the design. Both basin tests and CFD analysis results are presented with discussion on some specific hydrodynamic issues: vortex-induced vibration (VIV) of the global riser tower system, VIV of individual risers, and the dynamic stability of the global system (i.e. galloping). Finally, guidelines for the assessment of the hydrodynamic behaviour of such system geometries are proposed. The results of this paper demonstrate that the Greater Plutonio riser bundle represents an effective solution in term of hydrodynamic behaviour and is not sensitive to VIV fatigue or galloping.

scholarly journals Basic Research on the Automatic Reentry of Deepwater Riser by Active Control

1993 ◽  
Vol 1993 (174) ◽  
pp. 865-874 ◽  
Author(s):  
Hideyuki Suzuki ◽  
Koichiro Yoshida ◽  
Dongho Nam ◽  
Motohiko Murai ◽  
Akio Usami ◽  
...  
Keyword(s):  
Active Control ◽  
Basic Research ◽  
Deepwater Riser

Deepwater Riser Management

2000 ◽  
Author(s):  
I. Cummins ◽  
W. Todd
Keyword(s):  
Deepwater Riser

An Assessment of EOF Current Scatter Diagrams With Respect to Riser VIV Fatigue Damage

2002 ◽  
Author(s):  
Trond Stokka Meling ◽  
Kenneth Johannessen Eik ◽  
Einar Nygaard
Keyword(s):  
Fatigue Damage ◽  
Principal Components ◽  
Empirical Orthogonal Functions ◽  
Time Varying ◽  
Scatter Diagram ◽  
Orthogonal Functions ◽  
Vortex Induced Vibrations ◽  
Deepwater Riser ◽  
Diagram Approach ◽  
Current Modelling

The accuracy of current modelling is critical when considering deepwater riser fatigue damage caused by vortex-induced vibrations (VIV). In the present study the use of empirical orthogonal functions (EOF) to extract the governing characteristics from huge amounts of current measurements has been assessed. The amplitudes of the time varying principal components (PC) have been organized into bins in scatter diagrams. The accuracy of this scatter diagram approach with different numbers of EOF modes involved has been evaluated in terms of riser VIV fatigue damage.

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