Machine Learning for Subsea Pipeline Reeling Mechanics

Author(s):  
Eric Giry ◽  
Vincent Cocault-Duverger ◽  
Martin Pauthenet ◽  
Laurent Chec

Abstract Installation of subsea pipelines using reeling process is an attractive method. The pipeline is welded in long segments, typically several kilometers in length, and reeled onto a large diameter drum. The pipeline is then transported onto such reel to the offshore site where it is unreeled and lowered on the seabed. The deformation imposed on the pipeline while spooled onto the drum needs to be controlled so that local buckling is avoided. Mitigation of such failure is generally provided by proper pipeline design & reeling operation parameters. Buckling stems from excessive strain concentration near the circumferential weld area resulting from strength discontinuity at pipeline joints, mainly depending on steel wall thickness and yield strength. This requires the characterization of critical mismatches obtained by trial and error. Such method is a long process since each “trial” requires a complete Finite Element Analysis run. Such simulations are complex and lengthy. Occasionally, this can drive the selection of the pipeline minimum wall thickness, which is a key parameter for progressing the project. The timeframe of such method is therefore not compatible with such a key decision. The paper discusses the use of approximation models to capitalize on the data and alleviate the design cost. To do so, design of experiments and automation of the computational tool chain are implemented. It is demonstrated that initial complex chain of FEA computational process can be replaced using design space description and exploration techniques such as design of experiments combined with advanced statistical regression techniques in order to provide an approximation model. This paper presents the implementation of such methodology and the results are discussed.

2011 ◽  
Vol 328-330 ◽  
pp. 136-142
Author(s):  
Shun Yao Jin ◽  
Zhong Guo Huang ◽  
Zong Ke Shao ◽  
Ming Xiang Li ◽  
Hui Lai Sun ◽  
...  

This paper expounds the application of rotary expanding process to manufacture the large-diameter hot-rolled seamless gas cylinder. Through analytic geometry method, an equation is established among the tail roll gap, roll distance and the plug protrusion distance. 3D drawing software CATIA-V5 is applied to build 3d models of steel tube and rolling tools. The rolling process is simulated by MSC.Marc FEA (finite element analysis) software. Marc’s second development function and FORTRAN software’s extracting finite element node coordinates function are applied to calculate the wall thickness uniformity. A novel method to calculate the wall thickness uniformity after finite element analysis is proposed. The wall thickness uniformity of steel tube after rolling is well simulated and compared by MSC.Marc FEA software, which can help the technologist to predict and choose the best rolling parameter. For gas cylinder rolling, the tail roll gap should be set to 17mm. The roller distance and the plug protrusion distance should be set as 342mm and 78mm separately.


Author(s):  
John Barrett ◽  
Shawn Kenny ◽  
Ryan Phillips

Pipeline structural integrity is a critical component of pipeline design in extreme environmental conditions. Severe loads may be an issue in pipeline design if differential ground movement is prevalent in the design region, e.g. ground faulting and permafrost heave and settlement. Iceberg or ice keel interaction and large seabed deformations interacting may also be a critical design integrity issue for offshore pipelines in ice environments. Numerical finite element modelling procedures have been developed to assess the bending moment and strain capacity of several pipelines over various typical pipeline parameters. This study looks at the effects of girth-weld imperfection on the bending response of welded pipelines. Limited guidance is provided by pipeline design standards, for example DNV OS-F101 and CSA Z662, as to how to account for girth weld effects on the local buckling response. This paper investigates girth weld effects across a range of practical design parameters. Calibration of the numerical analysis was performed using available data, from full-scale tests and finite element analysis, for girth welded pipes in order to obtain confidence in the numerical procedure. The significance of girth weld effects was to reduce the peak bending moment capacity by 10% whereas strain capacity was reduced by as much as 35% based on the degree of girth weld imperfection. Girth weld effects have been acknowledged in industry, however, further research and physical testing is required to fully understand the problem, as shown in this paper.


2011 ◽  
Vol 320 ◽  
pp. 45-51
Author(s):  
Shun Yao Jin ◽  
Zhong Guo Huang ◽  
Zong Ke Shao ◽  
Qing Hua Yuan ◽  
Jian Wei

This paper expounds the application of rotary expanding process to manufacture the large-diameter hot-rolled seamless gas cylinder. 3D drawing software CATIA-V5 is applied to build 3d models of steel tube and rolling tools. Deformation feature of rotary expanding process is analyzed by using MSC.Marc FEA (finite element analysis) software to simulate the rolling process. As a result, it provides a scientific theory for optimizing the rotary expanding process and improving the quality of steel tube. It proposes a novel method to calculate the wall thickness uniformity after finite element analysis. Marc’s second development function and FORTRAN software’s extracting finite element node coordinates function are applied to calculate the wall thickness uniformity. The rotary expanding process can control the wall thickness uniformity well. The wall thickness uniformity of steel tube after rolling is simulated well by using MSC.Marc FEA software, which can help the technologist to predict the influence of wall thickness uniformity owing to the change of process design, and to provide guidance for production.


2011 ◽  
Vol 255-260 ◽  
pp. 369-373
Author(s):  
Jun Ling Chen ◽  
Xin Huang ◽  
Ren Le Ma

One large-diameter and non-circular steel tube was adopted in Henan TV tower (China). This special cross-section consists of three flat plates welded to three arc plates one by one. This paper studies the critical local buckling behavior of steel plates by using the finite element analysis method. Initial geometric imperfections and residual stresses presented in steel plates, material yielding and strain hardening were taken into account in the nonlinear analysis. An experimental study was performed to verify the capacity ability of this special steel tube. Based on the results obtained from the nonlinear finite element analyses and experiments, a set of design recommendations are provided for ensuring the safety of this special tube in Henan TV tower.


Author(s):  
Eduardo Oazen ◽  
Bruno R. Antunes ◽  
Carlos O. Cardoso ◽  
Rafael F. Solano

Wall thickness often presents a considerable influence in offshore pipeline capital expenditure (CAPEX). This influence is enhanced in design of ultra deepwater trunk lines of large diameter, where any wall thickness increase provides a huge impact on project costs. In ultra deepwater scenarios, thicker pipelines may eventually implicate not only in higher costs, but may also compromise the project feasibility due to installation load constraints related to laying vessels availability. One potential way to reduce the pipeline wall thickness is to calibrate fitness-for-purpose safety factors through application of structural reliability methods, instead of utilizing the standardized safety factors presented in international codes. Since mid-nineties, several offshore pipeline design codes have been allowing the calibration of safety factors by structural reliability analysis. The purpose of such an allowance is that structural reliability methods would eliminate some eventual conservatism presented in the safety factors proposed by codes. Although this enables the achievement of optimized safety factors, more than fifteen years have passed and only few pipeline projects have taken advantage of the benefits of safety factor calibration. This paper evaluates which potential benefits are available through safety factor calibration, particularly for wall thickness reduction purposes in ultra deepwater pipeline design. Calibrated safety factors are presented for some scenarios related to ultra deepwater export pipelines, considering “system collapse criteria” limit state. The calibrated safety factors are compared with the standardized safety factors presented by international pipeline design codes. The potential for safety factor reduction by the utilization of linepipes with more stringent manufacturing tolerances and the consideration of the thermal ageing imposed by coating application are also discussed.


2011 ◽  
Vol 374-377 ◽  
pp. 2430-2436
Author(s):  
Gang Shi ◽  
Zhao Liu ◽  
Yong Zhang ◽  
Yong Jiu Shi ◽  
Yuan Qing Wang

High strength steel sections have been increasingly used in buildings and bridges, and steel angles have also been widely used in many steel structures, especially in transmission towers and long span trusses. However, high strength steel exhibits mechanical properties that are quite different from ordinary strength steel, and hence, the local buckling behavior of steel equal angle members under axial compression varies with the steel strength. However, there is a lack of research on the relationship of the local buckling behavior of steel equal angle members under axial compression with the steel strength. A finite element model is developed in this paper to analyze the local buckling behavior of steel equal angle members under axial compression, and study its relationship with the steel strength and the width-to-thickness ratio of the angle leg. The finite element analysis (FEA) results are compared with the corresponding design method in the American code AISC 360-05, which provides a reference for the related design.


2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Sergio Ruiz de Galarreta ◽  
Aitor Cazón ◽  
Raúl Antón ◽  
Ender A. Finol

The goal of this work is to develop a framework for manufacturing nonuniform wall thickness replicas of abdominal aortic aneurysms (AAAs). The methodology was based on the use of computed tomography (CT) images for virtual modeling, additive manufacturing for the initial physical replica, and a vacuum casting process and range of polyurethane resins for the final rubberlike phantom. The average wall thickness of the resulting AAA phantom was compared with the average thickness of the corresponding patient-specific virtual model, obtaining an average dimensional mismatch of 180 μm (11.14%). The material characterization of the artery was determined from uniaxial tensile tests as various combinations of polyurethane resins were chosen due to their similarity with ex vivo AAA mechanical behavior in the physiological stress configuration. The proposed methodology yields AAA phantoms with nonuniform wall thickness using a fast and low-cost process. These replicas may be used in benchtop experiments to validate deformations obtained with numerical simulations using finite element analysis, or to validate optical methods developed to image ex vivo arterial deformations during pressure-inflation testing.


2014 ◽  
Vol 69 (7) ◽  
Author(s):  
Jaswar Koto ◽  
Abd. Khair Junaidi ◽  
M. H. Hashim

Offshore pipeline is mainly to transport crude oil and gas from offshore to onshore. It is also used to transport crude oil and gas from well to offshore platform and from platform to another platform. The crude oil and gas horizontally flows on the seabed, and then vertically flows inside the riser to the offshore platform. One of current issues of the oil and gas transportation system is an end expansion caused by the axial force. If the end expansion occurs over it limit can cause overstress to riser. This paper explores the effect of axial force toward local buckling in end expansion. In the study, development of programming in visual basic 2010 firstly was constructed using empirical equation. The programming code, then, was validated by comparing simulation result with actual data from company. As case study, the end expansion for various thicknesses of pipes was simulated. In this programming, DNV regulation is included for checking either design complied or not with regulation. However, DNV regulation doesn’t have specific rule regarding the end expansion but it is evaluated under load displacement control under strain condition.


Author(s):  
Dale Millward

Effective pipeline design and regular maintenance can assist in prolonging the lifespan of subsea pipelines, however the presence of marine vessels can significantly increase the risk of pipeline damage from anchor hazards. As noted in the Health and Safety Executive – Guideline for Pipeline Operators on Pipeline Anchor Hazards 2009. “Anchor hazards can pose a significant threat to pipeline integrity. The consequences of damage to a pipeline could include loss of life, injury, fire, explosion, loss of buoyancy around a vessel and major pollution”. This paper will describe state of the art pipeline isolation tooling that enables safe modification of pressurised subsea pipelines. Double Block and Bleed (DBB) isolation tools have been utilised to greatly reduce downtime, increase safety and maximise unplanned maintenance, providing cost-effective solutions to the end user. High integrity isolation methods, in compliance with international subsea system intervention and isolation guidelines (IMCA D 044 / IMCA D 006), that enable piggable and unpiggable pipeline systems to be isolated before any breaking of containment, will also be explained. This paper will discuss subsea pipeline damage scenarios and repair options available to ensure a safe isolation of the pipeline and contents in the event of an incident DNV GL type approved isolation technology enables the installation of a fail-safe, DBB isolation in the event of a midline defect. The paper will conclude with case studies highlighting challenging subsea pipeline repair scenarios successfully executed, without depressurising the entire pipeline system, and in some cases without shutting down or interrupting production.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Guoqing Liu ◽  
Yanhong Zhang ◽  
Ming Xiao

In order to explore the influence of internal water on the seismic response of hydraulic tunnel, the combined mechanical analysis models of multimaterial including surrounding rock, lining structure, and internal water are built. Based on the explicit central difference method, the dynamic finite element analysis methods for rock, lining, and water are discussed, respectively. The dynamic contact force method is used to simulate the rock-lining contact interaction, and the arbitrary Lagrange-Euler (ALE) method is used to simulate the lining-water coupling interaction. Then a numerical simulation analysis method for combined seismic response of rock-lining-water system in hydraulic tunnel is proposed, and the detailed solving steps are given. This method is used to study the seismic stability characteristics of the water diversion tunnel in a hydropower station, and the displacement, stress, and damage failure characteristics of the lining structure under the conditions of no water, static water, and dynamic water are comparatively analyzed. The results show that the hydrostatic pressure restricts the seismic response of the lining, while the hydrodynamic pressure exacerbates its seismic response and leads to damage, separation, and slip failure appearing on the haunch, which can provide a scientific reference for the seismic design of hydraulic tunnel with high water head and large diameter.


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