New Frontiers in the Design of Steel Catenary Risers for Floating Production Systems

2001 ◽  
Vol 123 (4) ◽  
pp. 153-158 ◽  
Author(s):  
Basim B. Mekha
Keyword(s):  
New Technologies ◽  
Production Systems ◽  
Random Wave ◽  
Environmental Loads ◽  
Steel Catenary Riser ◽  
Field Development ◽  
Steel Catenary Risers ◽  
Motion Characteristics ◽  
Vessel Motion ◽  
Water Depths

The steel catenary riser (SCR) concept has recently been used in almost every new deepwater field development around the world. Shell pioneered the implementation of the SCR concept in 1994 on its Auger tension leg platform (TLP) in 872 m (2860 ft) water depth. Since then, SCRs have been vital to deepwater field developments. Their use has given a new dimension to oil exploration and transportation in water depths where other riser concepts could not tolerate the environmental loads or would have become very costly. SCR designs are very sensitive to floating support platform or vessel motion characteristics to which they are typically attached. In addition to pipe stresses, the main design issue for the SCR concept is fatigue related. There are two main sources for fatigue: random wave fatigue and vortex-induced vibration (VIV) fatigue. The former is due to wave action and the associated platform motion characteristics. The VIV fatigue is mainly due to current conditions. Fracture mechanics assessment is also an essential issue that must be addressed in the design of SCRs. This paper presents a brief history in the use and development of SCRs since the first project implementation on Auger TLP in 1994. The paper also summarizes major steps that must be considered in the design of SCRs and how to explain their behavior in different water depths and environmental conditions. Existing design boundaries for SCRs are discussed with emphasis on the capabilities of new technologies that enable engineers to go beyond these boundaries. Projects with unique SCR features and their implementation are compiled and presented.

Multi-Pronged Approach for the Design of HP/HT Deepwater Steel Catenary Risers

2019 ◽  
Author(s):  
Gurudutt Bangalore ◽  
Yongming Cheng ◽  
Surya Banumurthy
Keyword(s):  
Problem Solving ◽  
Wall Thickness ◽  
Pipe Wall ◽  
Steel Catenary Riser ◽  
Riser Pipe ◽  
Successful Design ◽  
Steel Catenary Risers ◽  
Grade Material ◽  
Motion Characteristics ◽  
Vessel Motion

Abstract As the industry plans to move forward with the development of high pressure and high temperature (HP/HT) fields, challenges exist for the design of complaint risers in deepwater applications. The conventional wet tree application risers such as Steel Catenary Risers (SCRs) have proven to be mature technologies in the deepwater applications around the world. HP/HT application leads to many challenges in deepwater risers. This paper investigates ways to overcome the design challenges of deepwater SCRs using a multi-pronged approach. The paper first addresses the challenge in riser pipe wall thickness. The HP/HT applications require higher pipe wall thicknesses mainly governed by the burst pressure design requirements. The pipe wall thicknesses required for the HP/HT applications will result in very high installation loads, reeling issues with low D/t, fabrication (welding) challenges, high payloads to the host vessel, etc. Any optimization to the wall thickness design in terms of using higher grade material, advancements in welding technology and advantages to be gained in the use of design codes can potentially help in overcoming of these challenges. The pipe sizes used in the HP/HT applications can pose significant challenges to the touchdown zone (TDZ) of standard steel catenary riser configurations, in terms of experiencing large TDZ compressions and having fatigue life concerns. Use of different SCR problem-solving approaches — TDZ clump weights, Lazy Wave Steel Riser (SLWR) and weight optimized risers will be reviewed in this paper. Vessel motion characteristics can significantly affect the riser performance. Vessels with improved motions, particularly from the riser response viewpoint, can play a significant role in the selection of optimum riser configurations. This has to be achieved in the early stages of the project. Some of the work done recently in development of the optimized vessel performance particularly in the case of semi-submersibles and their implications on the riser design are studied in this paper. Design of the risers in HP/HT fields in deepwater applications presents significant challenges and requires a multi-dimensional problem solving approach. An example is provided in this paper for the investigation. A multi-pronged approach has to be adopted for the successful design of riser system for HP/HT deepwater applications.

On the Wave and VIV Fatigue of Steel Catenary Risers Connected to Floating Structures

2002 ◽  
Author(s):  
Basim B. Mekha
Keyword(s):  
Fatigue Damage ◽  
Random Wave ◽  
Pipeline System ◽  
Floating Structure ◽  
Drift Motion ◽  
Steel Catenary Riser ◽  
Slow Drift ◽  
Response Amplitude Operators ◽  
Motion Characteristics ◽  
Vessel Motion

The Steel Catenary Riser (SCR) concept has been considered as a vital option for most new deepwater field developments around the world. The use of an SCR, as a pipe connecting the export pipeline system and/or remote wells and infield flowline to a floating structure, has given more flexibility and potential to the oil exploration and transportation in water depths where other riser concepts would not tolerate the hydrostatic loads or would have become very costly. Major design concerns of the SCR pipes connected to a floating structure are the dynamic motion and the fatigue damage. The SCRs are very sensitive to the platform or vessel motion characteristics to which they would be attached as well to the environmental loads. The two main sources of fatigue are the random wave sea states and the associated platform motion and vortex induced vibration (VIV) due to current. The wave sea states are represented by wave spectra while the platform motions are applied as first order Response Amplitude Operators (RAOs) and second order slow drift motions. This paper gives a brief introduction about the development of the fatigue analysis methods that have been used to date. Results of parametric studies investigating several effects on the fatigue damage of the SCRs are presented. Some of these effects include flexible joint rotational stiffness, VIV analysis parameters, slow drift motion effects. The results will be for different size risers and fluid contents.

Emerging Industrial Revolution: Symbiosis of Industry 4.0 and Circular Economy: The Role of Universities

2020 ◽  
Vol 25 (3) ◽  
pp. 505-525 ◽  
Author(s):  
Seeram Ramakrishna ◽  
Alfred Ngowi ◽  
Henk De Jager ◽  
Bankole O. Awuzie
Keyword(s):  
Economic Growth ◽  
Circular Economy ◽  
Industry 4.0 ◽  
Business Models ◽  
Industrial Revolution ◽  
New Technologies ◽  
Production Systems ◽  
Fourth Industrial Revolution ◽  
New Jobs

Growing consumerism and population worldwide raises concerns about society’s sustainability aspirations. This has led to calls for concerted efforts to shift from the linear economy to a circular economy (CE), which are gaining momentum globally. CE approaches lead to a zero-waste scenario of economic growth and sustainable development. These approaches are based on semi-scientific and empirical concepts with technologies enabling 3Rs (reduce, reuse, recycle) and 6Rs (reuse, recycle, redesign, remanufacture, reduce, recover). Studies estimate that the transition to a CE would save the world in excess of a trillion dollars annually while creating new jobs, business opportunities and economic growth. The emerging industrial revolution will enhance the symbiotic pursuit of new technologies and CE to transform extant production systems and business models for sustainability. This article examines the trends, availability and readiness of fourth industrial revolution (4IR or industry 4.0) technologies (for example, Internet of Things [IoT], artificial intelligence [AI] and nanotechnology) to support and promote CE transitions within the higher education institutional context. Furthermore, it elucidates the role of universities as living laboratories for experimenting the utility of industry 4.0 technologies in driving the shift towards CE futures. The article concludes that universities should play a pivotal role in engendering CE transitions.

Dynamic Optimization of Steel Catenary Risers Based on Reliability Using Metamodel

2010 ◽  
Author(s):  
Wenqing Zheng ◽  
Hezhen Yang
Keyword(s):  
Dynamic Optimization ◽  
Computational Cost ◽  
Minimum Cost ◽  
Probabilistic Constraints ◽  
Optimization Approach ◽  
Element Analysis ◽  
Steel Catenary Riser ◽  
Reliability Based Design ◽  
Minimum Cost Design ◽  
Steel Catenary Risers

Reliability based design optimization (RBDO) of a steel catenary riser (SCR) using metamodel is investigated. The purpose of the optimization is to find the minimum-cost design subjecting to probabilistic constraints. To reduce the computational cost of the traditional double-loop RBDO, a single-loop RBDO approach is employed. The performance function is approximated by using metamodel to avoid time consuming finite element analysis during the dynamic optimization. The metamodel is constructed though design of experiments (DOE) sampling. In addition, the reliability assessment is carried out by Monte Carlo simulations. The result shows that the RBDO of SCR is a more rational optimization approach compared with traditional deterministic optimization, and using metamodel technique during the dynamic optimization process can significantly decrease the computational expense without sacrificing accuracy.

ECA Methodology for Fatigue Design of Risers and Flowlines

2007 ◽  
Author(s):  
C. H. Luk ◽  
T. J. Wang
Keyword(s):  
Fracture Mechanics ◽  
Design Method ◽  
Steel Catenary Riser ◽  
Fatigue Design ◽  
Wide Range ◽  
Fatigue And Fracture ◽  
Level 3 ◽  
Fatigue Loads ◽  
Vessel Motion ◽  
Level 2

Engineering Criticality Assessment (ECA) is a procedure based on fracture mechanics that may be used to supplement the traditional S-N approach and determine the flaw acceptance and inspection criteria in fatigue and fracture design of risers and flowlines. A number of design codes provide guidance for this procedure, e.g. BS-7910:2005 [1]. However, more investigations and example studies are still needed to address the design implications for riser and flowline applications. This paper provides a review of the existing ECA methodology, presents a fracture mechanics design method for a wide range of riser and flowline fatigue problems, and shows flaw size results from steel catenary riser (SCR) and flowline (FL) examples. The first example is a deepwater SCR subjected to fatigue loads due to vessel motion and riser VIV. The second example is a subsea flowline subjected to thermal fatigue loads. The effects of crack re-characterization and material plasticity on the Level-2 and Level-3 ECA results of the SCR and flowline examples are illustrated.

Investigation of Impact of New Design Code on Riser System Design

2009 ◽  
Author(s):  
Alan Yu ◽  
Paul Stanton ◽  
Yongming Cheng
Keyword(s):  
System Design ◽  
Production Systems ◽  
Design Code ◽  
Finite Element Program ◽  
Stress Evaluation ◽  
Element Program ◽  
Steel Catenary Risers ◽  
Ease Of Access ◽  
The Impact ◽  
Gas Lift

Top tensioned risers are fluid conduits from subsea equipment to surface floating production platforms. The advantages of using top tensioned risers are the ability to drill and complete through the production riser, ease of access of the production trees for gas lift operation, and the simplicity of workover and redrill. The integrity of a riser system plays an important role in deepwater developments. Top tensioned risers (TTRs) and steel catenary risers (SCRs) have been widely used with floating production systems such as Spars and TLPs. API RP 2RD [1] has been used to guide riser system design for the last decade. API RP 2RD is being revised as a code (ISO 13628-12) that will also be adopted as a new API code. This paper investigates the impacts of the new design code on the riser system design. This paper first discusses the differences between ISO/WD 13628-12 and the existing API RP 2RD code, particularly the section on design criteria for pipes. The Holstein top tensioned riser system is chosen as an example to evaluate the riser system design impacts. The risers have been installed and successfully producing oil since 2005. The results of the nonlinear finite element program ABAQUS used to analyze the Holstein top tensioned risers were evaluated according to the API RP 2RD. The same analytical results are used for evaluating the impact of the proposed ISO 13628-12 in the area of stress evaluation.

scholarly journals تقنية النشـــــــــر الالكتروني وتطبيقاتها في التصميم

لارك ◽  
2019 ◽  
Vol 1 (24) ◽  
pp. 72-92
Author(s):  
باسم محمد صالح مهدي
Keyword(s):  
Production Process ◽  
New Technologies ◽  
Electronic Publishing ◽  
Production Systems ◽  
Design Activity ◽  
Technical Factor ◽  
Design Structure ◽  
Art Design ◽  
New Vision ◽  
Publishing Technology

The digital technology, the emergence of the world has made a major breakthrough and a stunning advance in the entire production process, to the extent sing perfectly for resorting to the methods of traditional, which depends on the accuracy and skill of the technical factor, which can be said that the use of computers and devices connected to it is the only option for workers in printing and design activity, and to build production systems open and integrated, consisting of Sources of different electronic items, with each other in the works and one variable efficiency, introducing a complimentary radical changes in various fields of life, to come look re-read art design technology means more modern and sophisticated, and the completion of new dimensions in vision and receiving Based on the above, the researcher is seeking to detect style, approach and style that Hiatt design in accordance with the new tools and methods not only help him to Realize his ideas of new technologies, but make him think in a different way in which effort and creativity with us become different, too, it has provided a revolution techniques, tools and materials to give a new vision and input to update practices to accomplish the business of design and to modernize the design structure of form and content in line with the conceptual variables art design will help him to accomplish his determination in line with the idea to add Artistic touches provided by editing images and text programs in Computer, Kasasaat application without them printed design seems uninteresting, it was purely to four Investigation Department, the first chapter dealt with the problem and the importance and goals as well as the limits of research and definition of terms, either Chapter II addressed the theoretical framework of the research, and the third chapter research methodology and indicators, and then analyzing the samples, the latest findings, conclusions and recommendations, and, it was the most important results : 1-Electronic publishing technology caused a boom and a stunning development in the entire production process design, sing for resorting to traditional methods                                                      2-Computer entered in all areas of life, including the design, it may enrich a big role in this area with various characteristics of the many possibilities for use and employment                                                                                                                           . 3-Art design has the potential of graphical and wide through the multiplicity of different techniques and tools, leaving options open for the artist to produce multiple ideas,        

Sensitivity Study of Critical Parameters Influencing the Uncertainty of Fatigue Damage in Steel Catenary Risers

2010 ◽  
Author(s):  
Feng Zi Li ◽  
Ying Min Low
Keyword(s):  
Fatigue Damage ◽  
Cost Effective ◽  
Sensitivity Study ◽  
Structural Safety ◽  
Critical Parameters ◽  
Design Parameters ◽  
Steel Catenary Riser ◽  
Bending Stresses ◽  
Steel Catenary Risers ◽  
Touchdown Point

The most challenging aspect of a deepwater development is the riser system, and a cost-effective choice is the Steel Catenary Riser (SCR). Fatigue is often a governing design consideration, and it is usually most critical at the touchdown point (TDP) where static and dynamic bending stresses are highest. Unfortunately, it is also at this region that uncertainty is the maximum. The increased uncertainty casts doubt on the applicability of generic safety factors recommended by design codes, and the most consistent way of ensuring the structural safety of the SCR is to employ a reliability-based approach, which has so far not received attention in SCR design. As the number of basic random variables affects the complexity of a reliability analysis, these variables should be selected with caution. To this end, the aim of this paper is to draw up a comprehensive list of design parameters that may contribute meaningfully to the uncertainty of the fatigue damage. From this list, several parameters are selected for sensitivity studies using the commercial package Orcaflex. It is found that variations in seabed parameters such as soil stiffness, soil suction and seabed trench can have a pronounced influence on the uncertainty of the fatigue damage at the touchdown point.

A procedure to estimate the lateral force in clay-pipe interaction after breakout

2021 ◽  
pp. 3
Author(s):  
Pablo Cesar Trejo ◽  
Jose Renato M.S. Oliveira ◽  
Márcio S.S. Almeida ◽  
Maria C.F. Almeida ◽  
Mario A. Vignoles
Keyword(s):  
Oil And Gas ◽  
New Technologies ◽  
Production Systems ◽  
Low Cost ◽  
Experimental Studies ◽  
Leading Edge ◽  
Lateral Force ◽  
Pipeline System ◽  
Centrifuge Tests ◽  
Clay Pipe

The development of new offshore oil and gas fields is continuously expanding to ultra-deep waters. This tendency and the necessity of reducing project costs have been stimulating the development of new technologies as well as the enhancement of floating production systems. In this regard, pipelines and flexible riser systems have been getting more attention due to its low cost of installation and operation. In order to project a pipeline system, it is important to understand the pipe-soil interaction mechanisms and quantify the influence of soil behaviour on pipe response caused by lateral movement such as thermal buckling. The loads that a pipeline is subjected have been a topic of many experimental studies that aim to reproduce those loads in a realistic manner. This present study concerns the analysis of lateral clay-pipe interaction associated with large deformations and berm formation process at the leading edge of the pipe during movement at given burial depths. A series of centrifuge tests was conducted to assess the relationship between horizontal force and lateral pipe displacement. The breakout force experimental results were compared with different literature proposals, showing a good agreement. A procedure was also proposed to evaluate the normalized lateral force through the combination of two different approaches. The results showed a good comparison with the centrifuge experimental data.

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