Full-History Finite Element Modelling of Pipe-in-Pipe Flowline System: From Installation to Operation

Author(s):  
Facheng Wang ◽  
Zhigang Liu ◽  
Xinshuai Liu

Developments of oil and gas reservoirs in South China Sea are presently accelerated, to cope with the significant increase in energy demand from the mainland. Pipe-in-Pipe (PIP) flowline systems have been widely employed in this region and are continuously being considered for further developments. This is due to its significant thermal insulation capacity to deal with the High Pressure and High Temperature (HPHT) issue. However, the methods in industry for design of PIP systems usually have two side extremes. Simplified analytical approach may lack of accuracy and detailed FE analysis always brings considerably sophisticated modelling and post-processing tasks. To overcome this situation, COTEC Offshore Solutions, together with its mother company, China Offshore Oil Engineering Company, have developed a cost-effective, beam elements based, 3D simulation model using ABAQUS, a general purpose finite element analysis (FEA) package. The mode allows complicated structures of PIP system to be represented in an effective way and adopts a representation of stinger for S-lay installation analysis. A full-history time-dominate analysis from installation to operation is performed in one model, rather than the commonly used ‘snapshot’ analysis. In this study, a simplified modeling guidance of PIP components have been suggested. On the basis of the guidance, a novel 3D beam-elements based model has been produced to accurately represent complex PIP structural behaviors, but with minimum increase in modeling complexity. The analysis is carried out on the time-domain basis, which permits the full strain and stress history of the installation and operation to be observed and the most onerous time-point during the full installation and operation to be captured.

Author(s):  
Rama Subba Reddy Gorla

Heat transfer from a nuclear fuel rod bumper support was computationally simulated by a finite element method and probabilistically evaluated in view of the several uncertainties in the performance parameters. Cumulative distribution functions and sensitivity factors were computed for overall heat transfer rates due to the thermodynamic random variables. These results can be used to identify quickly the most critical design variables in order to optimize the design and to make it cost effective. The analysis leads to the selection of the appropriate measurements to be used in heat transfer and to the identification of both the most critical measurements and the parameters.


2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Chen Xia ◽  
Chengzhi Qi ◽  
Xiaozhao Li

Transmitting boundaries are important for modeling the wave propagation in the finite element analysis of dynamic foundation problems. In this study, viscoelastic boundaries for multiple seismic waves or excitations sources were derived for two-dimensional and three-dimensional conditions in the time domain, which were proved to be solid by finite element models. Then, the method for equivalent forces’ input of seismic waves was also described when the proposed artificial boundaries were applied. Comparisons between numerical calculations and analytical results validate this seismic excitation input method. The seismic response of subway station under different seismic loads input methods indicates that asymmetric input seismic loads would cause different deformations from the symmetric input seismic loads, and whether it would increase or decrease the seismic response depends on the parameters of the specific structure and surrounding soil.


Author(s):  
Scott D. Ironside ◽  
L. Blair Carroll

Enbridge Pipelines Inc. operates the world’s longest and most complex liquids pipeline network. As part of Enbridge’s Integrity Management Program In-Line Inspections have been and will continue to be conducted on more than 15,000 km of pipeline. The Inspection Programs have included using the most technologically advanced geometry tools in the world to detect geometrical discontinuities such as ovality, dents, and buckles. During the past number of years, Enbridge Pipelines Inc. has been involved in developing a method of evaluating the suitability of dents in pipelines for continued service. The majority of the work involved the development of a method of modeling the stresses within a dent using Finite Element Analysis (FEA). The development and validation of this model was completed by Fleet Technology Limited (FTL) through several projects sponsored by Enbridge, which included field trials and comparisons to previously published data. This model combined with proven fracture mechanics theory provides a method of determining a predicted life of a dent based on either the past or future operating conditions of the pipeline. CSA Standard Z662 – Oil and Gas Pipeline Systems provides criteria for the acceptability of dents for continued service. There have been occurrences, however, where dents that meet the CSA acceptability criteria have experienced failure. The dent model is being used to help define shape characteristics in addition to dent depth, the only shape factor considered by CSA, which contribute to dent failure. The dent model has also been utilized to validate the accuracy of current In-Line Inspection techniques. Typically a dent will lose some of its shape as the overburden is lifted from the pipeline and after the indentor is removed. Often there can be a dramatic “re-rounding” that will occur. The work included comparing the re-rounded dent shapes from a Finite Element model simulating the removal of the constraint on the pipe to the measured dent profile from a mold of the dent taken in the field after it has been excavated. This provided a measure of the accuracy of the tool. This paper will provide an overview of Enbridge’s dent management program, a description of the dent selection process for the excavation program, and a detailed review of the ILI validation work.


2018 ◽  
Vol 13 (2) ◽  
pp. 146-155 ◽  
Author(s):  
Zhuoya Yuan ◽  
Pui-Lam Ng ◽  
Darius Bačinskas ◽  
Jinsheng Du

To consider the effect of non-uniform shrinkage of box girder sections on the long-term deformations of continuous rigid frame bridges, and to improve the prediction accuracy of analysis in the design phase, this paper proposes a new simulation technique for use with general-purpose finite element program. The non-uniform shrinkage effect of the box girder is transformed to an equivalent temperature gradient and then applied as external load onto the beam elements in the finite element analysis. Comparative analysis of the difference in deflections between uniform shrinkage and nonuniform shrinkage of the main girder was made for a vehicular bridge in reality using the proposed technique. The results indicate that the maximum deflection of box girder under the action of non-uniform shrinkage is much greater than that under the action of uniform shrinkage. The maximum downward deflection of the bridge girder caused by uniform shrinkage is 5.6 mm at 20 years after completion of bridge deck construction, whereas the maximum downward deflection caused by non-uniform shrinkage is 21.6 mm, which is 3.8 times larger. This study shows that the non-uniform shrinkage effect of the girder sections has a significant impact on the long-term deflection of continuous rigid frame bridge, and it can be accurately simulated by the proposed transformation technique.


Author(s):  
Naveen Viswanatha ◽  
Mark Avis ◽  
Moji Moatamedi

The surround and the spider of the loudspeaker suspension are modelled in ANSYS to carry out finite element analysis. The displacement dependent nonlinearities arising from the suspension are studied and the material and geometric effects leading to the nonlinearities are parameterised. The ANSYS models are simulated to be excited by a sinusoidal load and the results are evaluated by comparison with the results obtained by a physical model. The paper illustrates how practical models can be analysed using cost effective finite element models and also the extension of the models to experiment on various parameters, like changing the geometry for optimisation, by computer simulation.


1993 ◽  
Vol 115 (3) ◽  
pp. 221-227
Author(s):  
A. K. Dhalla

Elevated temperature design has evolved over the last two decades from design-by-formula philosophy of the ASME Boiler and Pressure Vessel Code, Sections I and VIII (Division 1), to the design-by-analysis philosophy of Section III, Code Case N-47. The benefits of design-by-analysis procedures, which were developed under a US-DOE-sponsored high-temperature structural design (HTSD) program, are illustrated in the paper through five design examples taken from two U.S. liquid metal reactor (LMR) plants. Emphasis in the paper is placed upon the use of a detailed, nonlinear finite element analysis method to understand the structural response and to suggest design optimization so as to comply with Code Case N-47 criteria. A detailed analysis is cost-effective, if selectively used, to qualify an LMR component for service when long-lead-time structural forgings, procured based upon simplified preliminary analysis, do not meet the design criteria, or the operational loads are increased after the components have been fabricated. In the future, the overall costs of a detailed analysis will be reduced even further with the availability of finite element software used on workstations or PCs.


2015 ◽  
Vol 799-800 ◽  
pp. 196-200
Author(s):  
Abhilash M. Bharadwaj ◽  
Sonny Irawan ◽  
Saravanan Karuppanan ◽  
Mohamad Zaki bin Abdullah ◽  
Ismail bin Mohd Saaid

Casing design is one of the most important parts of the well planning in the oil and gas industry. Various factors affecting the casing material needs to be considered by the drilling engineers. Wells partaking in thermal oil recovery processes undergo extreme temperature variation and this induces high thermal stresses in the casings. Therefore, forecasting the material behavior and checking for failure mechanisms becomes highly important. This paper uses Finite Element Methods to analyze the behavior two of the frequently used materials for casing - J55 and L80 steels. Modeling the casing and application of boundary conditions are performed through Ansys Workbench. Effect of steam injection pressure and temperature on the materials is presented in this work, indicating the possibilities of failure during heating cycle. The change in diameter of the casing body due to axial restriction is also presented. This paper aims to draw special attention towards the casing design in high temperature conditions of the well.


Author(s):  
S. Nagasawa ◽  
H. Sakuta ◽  
M. Goto

Abstract This paper deals with conceptual orientation and system development of intelligent support system for general purpose FEA (finite element analysis) programs. An integrated support system called “InhierTalk” (Integrated interactive environment for hierarchical representation for FEA) has been developed in Smalltalk, an object oriented language, in order to confirm effectivity of hierarchical representation and to establish an optimum method of the system development. Two object-oriented knowledge models which consist of macro visual data representation and micro regularized data representation are proposed. In the development, it is found to be clear that active and passive evaluation methods are effective for construction of support system.


2001 ◽  
Author(s):  
Romil R. Tanov ◽  
Marlin Brueggert

Abstract The behavior of loosely woven fabrics differs significantly from other types of woven fabrics. Its unique characteristics have been successfully utilized for the correct operation of some recently developed occupant protection devices for the automotive and heavy machine and truck industry. However, this behavior cannot be efficiently modeled using the currently available material models within a finite element analysis scheme. Therefore, the aim of this work is to present the basics of a formulation of a material model for the analysis of loosely woven fabrics and its implementation in a general-purpose explicit finite element code. To assess the performance of the model, results from the simulation are presented and compared to real test data.


2021 ◽  
Author(s):  
Sinan Yıldırım ◽  
Ufuk Çoban ◽  
Mehmet Çevik

Suspension linkages are one of the fundamental structural elements in each vehicle since they connect the wheel carriers i.e. axles to the body of the vehicle. Moreover, the characteristics of suspension linkages within a suspension system can directly affect driving safety, comfort and economics. Beyond these, all these design criteria are bounded to the package space of the vehicle. In last decades, suspension linkages have been focused on in terms of design development and cost reduction. In this study, a control arm of a diesel public bus was taken into account in order to get the most cost-effective design while improving the strength within specified boundary conditions. Due to the change of the supplier, the control arm of a rigid axle was redesigned to find an economical and more durable solution. The new design was analyzed first by the finite element analysis software Ansys and the finite element model of the control arm was validated by physical tensile tests. The outputs of the study demonstrate that the new design geometry reduces the maximum Von Mises stress 15% while being within the elastic region of the material in use and having found an economical solution in terms of supplier’s criteria.


Sign in / Sign up

Export Citation Format

Share Document