Experimental Study and Finite Element Analysis for the Installation of a Pipeline Into an Existing Pipeline

2013 ◽  
Vol 135 (1) ◽  
Author(s):  
Yong Bai ◽  
Yu Binbin ◽  
Cheng Peng ◽  
Wang Ning
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Model Tests ◽  
Sensitivity Analyses ◽  
Radius Of Curvature ◽  
Flexible Pipe ◽  
Element Analysis ◽  
Analytical Studies ◽  
Plastic Pipe ◽  
Major Factors

Some metallic pipelines suffer from corrosion issues due to internal and external environmental conditions. The pipe-in-pipe technology has been developed by inserting a new pipe (e.g., plastic pipe or flexible pipe) into an existing pipeline. The pipe-in-pipe approach may be applicable to the reconstruction of an existing pipeline, where the existing pipe is used as protective casing and the inserted new pipe is used to contain corrosive petrochemicals. The new pipe is installed in the long existing pipeline with several bends. The magnitude of the pull-in load and the response of the inserted pipe are the major concerns during installation. This paper presents the installation process of inserting a plastic pipe into an existing steel pipe, based on model tests, finite element analysis (FEA), and analytical investigations. First, a series of model tests are presented. In order to optimize the process of installation, sensitivity analyses based on model tests were conducted to study the influence of some key parameters, including the radius of curvature of the pipeline and diameter of the pipe. Then ABAQUS finite element models were applied to analyze the major factors. In addition, analytical studies on calculating the pull-in load are presented to make a comparison with the FEA and model test results. Since little previous work has been done about simulating the installation process of this kind of rehabilitation, the proposed finite element analysis results and the analytical studies of the installation can serve as a feasibility study for the design and evaluation of offshore pipeline rehabilitation project.

Flexible Flowline Walking Tendency on Seabed With Longitudinal Undulations and Transverse Gradients

2018 ◽  
Author(s):  
Graeme Roberts ◽  
T. Sriskandarajah ◽  
Gianluca Colonnelli ◽  
Arnaud Roux ◽  
Alan Roy ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Temperature Gradients ◽  
Radius Of Curvature ◽  
Bend Radius ◽  
Lateral Buckling ◽  
Element Analysis ◽  
Slip Tendency ◽  
Start Ups ◽  
The Impact

A method of carrying out a combined axial walking and lateral buckling assessment for a flexible flowline has been developed using finite element analysis. The method overcomes limitations of screening assessments which could be inconclusive when applied either to a flexible flowline on an undulating seabed with transverse gradients or to one that buckles during hydrotest. Flexible flowlines that were to be surface-laid on a seabed with longitudinal undulations and transverse gradients were assessed using the method. The flexible flowlines were simulated in their as-laid state, and the simulation incorporated hydrotest pressure and the pressure & temperature gradients and transients associated with multiple start-ups. The objective was to quantify the axial walking and lateral slip tendency of the flexible flowlines and the impact that walking might have on the connected end structures. The lateral buckle locations predicted by finite element analysis were compared to a post-hydrotest survey and the radius of curvature from analysis was compared to the minimum bend radius of the flexible.

scholarly journals An Analysis Tool for the Installation of Submarine Cables in an S-Lay Configuration Including “In and Out of Water” Cable Segments

2020 ◽  
Vol 8 (1) ◽  
pp. 48 ◽  
Author(s):  
Vasileios A. Mamatsopoulos ◽  
Constantine Michailides ◽  
Efstathios E. Theotokoglou
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Design Criterion ◽  
Limiting Factors ◽  
Radius Of Curvature ◽  
Analysis Tool ◽  
Analysis Software ◽  
Element Analysis ◽  
Analysis And Design ◽  
Custom Made

Today, the offshore oil and gas and wind power industry is a heavily regulated segment, and current standards have established restrictions which yield a very limited weather window for submarine cable installations due to experience with cable failure in bad weather. There are two main limiting factors in current practice during cable installation of an S-lay configuration: the design criterion for the minimum allowable radius of curvature in the touch down point and the avoidance of axial compression in the touch down zone. Accurate assessment of the cable integrity during offshore installation has drawn great attention and is related to the existing available analysis and design tools. The main purpose of this paper is to develop and propose a quick and easy custom-made analysis tool, which is able to export similar results as sophisticated finite element analysis software. The developed tool utilizes analytical equations of a catenary-type submarine structure extended to account for varying cross-sections with different weights and/or stiffnesses, as is the real practice. A comparative study is presented in this paper to evaluate the significance for the modeling of the “out of water” cable segment required for accurate safety factor quantification during a laying operation. The efficiency and accuracy of the proposed tool are proven through a validation study comparing the results and the computational effort and time with commercial finite element analysis software. The analysis error in the case of not modeling the “out of water” cable part is significant, especially in shallow water areas, which proves the importance of using the proposed analysis tool.

An Experimental and Numerical Investigation of the Effect of Axial Thermal Gradients in Flexible Pipes

2017 ◽  
Author(s):  
Dag Fergestad ◽  
Frank Klæbo ◽  
Jan Muren ◽  
Pål Hylland ◽  
Tom Are Grøv ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cross Section ◽  
Measurement Techniques ◽  
Full Scale ◽  
Model Complexity ◽  
Flexible Pipe ◽  
Element Analysis ◽  
Flexible Pipes ◽  
Full Scale Testing

This paper discusses the structural challenges associated with high axial temperature gradients and the corresponding internal cross section forces. A representative flexible pipe section designed for high operational temperature has been subject to full scale testing with temperature profiles obtained by external heating and cooling. The test is providing detailed insight in onset and magnitude of relative layer movements and layer forces. As part of the full-scale testing, novel methods for temperature gradient testing of unbonded flexible pipes have been developed, along with layer force- and deflection-measurement techniques. The full-scale test set-up has been subject to numerous temperature cycles of various magnitudes, gradients, absolute temperatures, as well as tension cycling to investigate possible couplings to dynamics. Extensive use of finite element analysis has efficiently supported test planning, instrumentation and execution, as well as enabling increased understanding of the structural interaction within the unbonded flexible pipe cross section. When exploiting the problem by finite element analysis, key inputs will be correct material models for the polymeric layers, and as-built dimensions/thicknesses. Finding the balance between reasonable simplification and model complexity is also a challenge, where access to high quality full-scale tests and dissected pipes coming back from operation provides good support for these decisions. Considering the extensive full scale testing, supported by advanced finite element analysis, it is evident that increased attention will be needed to document reliable operation in the most demanding high temperature flexible pipe applications.

Finite Element Analysis of Flexible Pipes Under Compression

2014 ◽  
Author(s):  
Eduardo Ribeiro Malta ◽  
Clóvis de Arruda Martins
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Strength ◽  
Element Model ◽  
Large Displacements ◽  
Flexible Pipe ◽  
Element Analysis ◽  
Flexible Pipes ◽  
Compressive Loads ◽  
Surface Vessel

Axial compressive loads can appear in several situations during the service life of a flexible pipe, due to pressure variations during installation or due to surface vessel heave. The tensile armor withstands well tension loads, but under compression, instability may occur. A Finite Element model is constructed using Abaqus in order to study a flexible pipe compound by external sheath, two layers of tensile armor, a high strength tape and a rigid nucleus. This model is fully tridimensional and takes into account all kinds of nonlinearities involved in this phenomenon, including contacts, gaps, friction, plasticity and large displacements. It also has no symmetry or periodical limitations, thus permitting each individual wire of the tensile armor do displace in any direction. Case studies were performed and their results discussed.

Corrugated Board Flute-Shaped Finite Element Analysis and Optimization

2013 ◽  
Vol 477-478 ◽  
pp. 1205-1209 ◽  
Author(s):  
Wei Yuan ◽  
Gai Mei Zhang ◽  
Da Zhi Liao ◽  
Jing Liu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Compressive Strength ◽  
Gradual Transition ◽  
Radius Of Curvature ◽  
Element Analysis ◽  
Corrugated Board ◽  
Key Points ◽  
Corrugated Cardboard ◽  
Corrugated Structure

UV-shaped corrugated cardboard Fusion V-shaped and U-shaped structure the advantages made, to make up for the lack of V-type and two U-shaped corrugated cardboard, the higher the compressive strength, good elasticity, is widely used UV type corrugated manufacturing corrugated board. But no strict standards for UV-shaped concrete structure of corrugated board size parameter corresponding corrugating roll no uniform size of the corrugated shape, in order to achieve the best elasticity and compressive strength. First, by mathematical methods, the corrugated structure is analyzed, and analysis to facilitate research, to select the 1/4 cycle corrugated. Create multiple vertical auxiliary line level is divided into 10 equal parts, to identify key points in shape between the V-shaped and U-shaped curve, connecting into multiple segments curve. Studied the actual thickness of the corrugated board of 3.8mm, a smaller thickness and therefore a straight line can be connected to each group of the resultant key points simplify the corrugated curve, model 1/4 of a cycle of UV-shaped corrugated first determined, using the symmetry of the model to establish a cycle, 300mm side length of the square created by one cycle of replication, about 38 of the corrugated board corrugated cycle. Use of finite element analysis in ANSYS corrugated structure, including a gradual transition to a simplified model of the 11 U-shaped flute-shaped corrugated cardboard from the V-shaped set of material properties, loads are cloth pressure, research corrugated cardboard stress and strain, i.e., the smaller the radius of curvature of the curve can be obtained along corrugated, the closer the U-shaped, corrugated board having a larger strain, i.e. has good flexibility, consistent with the empirical data to prove the feasibility of this analysis method.

Upheaval Creep of Rock Dumped Flexible Flowline

2014 ◽  
Author(s):  
Yang Zhengmao ◽  
Kristian Norland ◽  
Neil Brown ◽  
Daniel Karunakaran
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Pressures ◽  
Elevated Temperatures ◽  
Water Injection ◽  
Analysis Model ◽  
Flexible Pipe ◽  
Element Analysis ◽  
Nonlinear Bending ◽  
Start Up

For the protection from dropped object/fishing trawl impact, flexible flowlines are normally trenched or rock-dumped. And hence, upheaval buckling and lateral buckling may be promoted by the elevated temperatures and high pressures. Due to the unique properties of un-bonded flexible flowline, the flexible flowline may creep in the trench or rock berm when it is subjected to cyclic pressure and temperature changes due to start-up and shut-down of flowline in service. In this paper, a finite element analysis model for the global buckling and upheaval creep of flexible flowline is proposed. In this model the effect of bending stiffness hysteresis are considered in addition to the temperature and pressure changes in each start-up/ shut-down cycle. A case study of a 10″ water injection flowline is performed by using finite element analysis software package ANSYS. The nonlinear general beam section is used to simulate the specific flexible pipe behavior, nonlinear bending behavior but linear axial behavior.

Sign in / Sign up

Export Citation Format

Share Document