A Screening Methodology to Rapidly Reduce ILI Data, Visualise and Determine Most Detrimental Defects in Pipelines

2017 ◽  
Author(s):  
Nicolas O. Larrosa ◽  
Pablo Lopez-Crespo ◽  
Robert A. Ainsworth
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Detailed Analysis ◽  
Field Data ◽  
Oil And Gas ◽  
Element Analysis ◽  
Starting Point

The amount of data requiring detailed analysis from that obtained during in-line inspection (ILI)is reduced by a screening methodology. The methodology uses ILI outputs (dimensions of flaws, orientation and distance from starting point) to generate a visualisation of the pits within the pipeline, a ranking of pits in terms of sphericity (roundness) and depth, to evaluate pit density and generate the models for finite element analysis. The rendering tool allows a clearer view of defects within the pipelines and provides a simplified way to focus on critical pits. For a particular case of in-field data provided by BP, the number of pits in a 12-inch riser of 11 km length was reduced from 1750 obtained to 43, 15 or 4 requiring analysis, depending on the level of conservatism introduced by the analyst. The tool will allow Oil and Gas owners and operators to reduce the immense amount of data obtained during pigging to a much less time-consuming set for flaw assessment.

An Approach to Reduce the Amount of ILI Data in Fatigue Analysis of Pits in Pipelines

2017 ◽  
Author(s):  
Nicolas O. Larrosa ◽  
Pablo Lopez-Crespo ◽  
Robert A. Ainsworth
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Detailed Analysis ◽  
Field Data ◽  
Oil And Gas ◽  
Fatigue Analysis ◽  
Element Analysis ◽  
Starting Point

This paper presents a screening methodology that is used to reduce the amount of data requiring detailed analysis from that obtained during in-line inspection (ILI). The methodology uses ILI outputs (dimensions of flaws, orientation and distance from starting point) to generate a visualisation of the pits within the pipeline, a ranking of pits in terms of sphericity (roundness) and depth, to evaluate pit density and generate the models for finite element analysis. The rendering tool allows a clearer view of defects within the pipelines and provides a simplified way to focus on critical pits. For a particular case of in-field data provided by BP, the number of pits in a 12-inch riser of 11 km length was reduced from 1750 obtained to 43, 15 or 4 requiring analysis, depending on the level of conservatism introduced by the analyst. The tool will allow Oil and Gas owners and operators to reduce the immense amount of data obtained during pigging to a much less time-consuming set for flaw assessment.

Design of the Full Scale Experiments for the Testing of the Tensile Strain Capacity of X52 Pipes With Girth Weld Flaws Under Internal Pressure and Tensile Displacement

2014 ◽  
Author(s):  
Celal Cakiroglu ◽  
Samer Adeeb ◽  
J. J. Roger Cheng ◽  
Millan Sen
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Internal Pressure ◽  
Tensile Strain ◽  
Oil And Gas ◽  
Full Scale ◽  
Element Analysis ◽  
Simultaneous Application ◽  
Strain Capacity ◽  
Tensile Strain Capacity

Pipelines can be subjected to significant amounts of tensile forces due to geotechnical movements like slope instabilities and seismic activities as well as due to frost heave and thaw cycles in arctic regions. The tensile strain capacity εtcrit of pipelines is crucial in the prediction of rupture and loss of containment capability in these load cases. Currently the Oil and Gas Pipeline Systems code CSA Z662-11 0 contains equations for the prediction of εtcrit as a function of geometry and material properties of the pipeline. These equations resulted from extensive experimental and numerical studies carried out by Wang et al [2]–[6] using curved wide plate tests on pipes having grades X65 and higher. Verstraete et al 0 conducted curved wide plate tests at the University of Ghent which also resulted in tensile strain capacity prediction methods and girth weld flaw acceptability criteria. These criteria are included in the European Pipeline Research Group (EPRG) Tier 2 guidelines. Furthermore Verstrate et al 0 introduced a pressure correction factor of 0.5 in order to include the effect of internal pressure in the tensile strain capacity predictions in a conservative way. Further research by Wang et al with full scale pipes having an internal pressure factor of 0.72 also showed that εtcrit decreases in the presence of internal pressure [10]–[15]. In their work, Wang et al presented a clear methodology for the design of full scale experiments and numerical simulations to study the effect of internal pressure on the tensile strain capacity of pipes with girth weld flaws [10]–[15]. However, there has been limited testing to enable a precise understanding of the tensile strain capacity of pipes with grades less than X65 as a function of girth weld flaw sizes and the internal pressure. In this paper the experimental setup for the testing of grade X52 full scale specimens with 12″ diameter and ¼″ wall thickness is demonstrated. In the scope of this research 8 full scale specimens will be tested and the results will be used to formulate the tensile strain capacity of X52 pipes under internal pressure. The specimens are designed for the simultaneous application of displacement controlled tensile loading and the internal pressure. Finite element analysis is applied in the optimization process for the sizes of end plates and connection elements. Also the lengths of the full scale specimens are determined based on the results from finite element analysis. The appropriate lengths are chosen in such a way that between the location of the girth weld flaw and the end plates uniform strain zones could be obtained. The internal pressure in these experiments is ranging between pressure values causing 80% SMYS and 30% SMYS hoop stress. The end plates and connection elements of the specimens are designed in such a way that the tensile displacement load is applied with an eccentricity of 10% of the pipe diameter with the purpose of increasing the magnitude of tensile strains at the girth weld flaw location. The results of two full scale experiments of this research program are presented. The structural response from the experiments is compared to the finite element simulation. The remote strain values of the experiment are found to be higher than the εtcrit values predicted by the equations in 0.

Steel Storage Tank Shell Settlement Assessment Based on Finite Element and API Standard 653 Analyses

2008 ◽  
Author(s):  
Mohamed R. Chebaro ◽  
Nader Yoosef-Ghodsi ◽  
Howard K. Yue
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Storage Tank ◽  
Field Data ◽  
Specific Information ◽  
Storage Tanks ◽  
Element Analysis ◽  
Fea Model ◽  
Actual Field ◽  
Allowable Settlement

API Standard 653 addresses issues related to the inspection, repair, alteration and reconstruction of steel storage tanks built according to API Standard 650 or API 12C to help maintain tank integrity. Although the standard covers three types of tank settlement, namely edge, bottom and shell, this paper focuses on the assessment of shell settlement. It also provides a comparison between an analytical model based on API Standard 653 and a finite element analysis (FEA) model that replicates field operating loading and settlement conditions of storage tanks. A basis for comparison between both models was established from the maximum allowable settlement and strain values. Several scenarios were generated using actual field data collected from steel storage tanks located in Alberta to illustrate the correlation between the two models. Specific information on the storage tanks under consideration cannot be disclosed for confidentiality reasons.

The Design and Analysis of the H Beam Structure Cup Support for Weighing Large Structure

2013 ◽  
Vol 717 ◽  
pp. 266-270
Author(s):  
Jin Bao Zhang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Detailed Analysis ◽  
Large Structure ◽  
Beam Structure ◽  
Stress Strain ◽  
Element Analysis ◽  
Force Condition ◽  
Allowable Range ◽  
H Beam

The H beam structure has high requirement for the force condition in weighing. The paper do a detailed analysis for the force condition of the cup support in the weighing procedure, through the design and finite-element analysis for the weighing cup support of the 3M101 module A12 cup support. Improves security and at the same time make the stress-strain in the weighing procedure in the allowable range.

Use of Finite Element Analysis for Stud Pre-Tension Determination of Large Diameter Integral Flanges With Ring Joint Gaskets

2010 ◽  
Author(s):  
Upali Panapitiya ◽  
Haoyu Wang ◽  
Syed Jafri ◽  
Paul Jukes
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Oil And Gas ◽  
Large Diameter ◽  
Three Dimensional ◽  
Oil And Gas Industry ◽  
Element Analysis ◽  
Axial Forces ◽  
Three Dimensional Finite Element

Large diameter integral steel flanges are widely used in many applications in the oil and gas industry. The flanges of nominal pipe sizes, 26-inch and above with ring-joint gaskets as specified in ASME B 16.47 Standard, are used in the offshore applications for the transportation of oil and gas from production facilities. These pipelines require flanged connections at end terminations, mid-line tie-ins and expansion loops. The conventional design of large diameter steel flanges is based on one-dimensional analytical methods similar to the procedure in ASME VIII Boiler and Pressure Vessel Code, Division 1 Appendix 2. The effects of axial forces and bending moments are approximated by calculating an equivalent pressure. This usually results in conservative designs for the large flanges because it estimates the required stud pre-tension based on the assumption that the gasket will be unloaded entirely to a minimum stress, whereas only a small section of the gasket is subjected to low stress. This technical paper presents the quasi-static, nonlinear, and three-dimensional finite element models of large diameter steel flanged joint for the determination of stud pre-tension and change of stud tension under various loading conditions. The finite element analysis results are compared with the results obtained by using the equivalent pressure method and flange “Joint Diagram”.

scholarly journals Burst Strength Analysis of Casing With Geometrical Imperfections

2006 ◽  
Vol 129 (4) ◽  
pp. 763-770 ◽  
Author(s):  
Xiaoguang Huang ◽  
Yanyun Chen ◽  
Kai Lin ◽  
Musa Mihsein ◽  
Kevin Kibble ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Strength Analysis ◽  
Element Analysis ◽  
Burst Strength ◽  
The Finite Element Analysis ◽  
Geometrical Imperfections ◽  
Major Factors

Accurately predicting the burst strength is very important in the casing design for the oil and gas industry. In this paper, finite element analysis is performed for an infinitely long thick walled casing with geometrical imperfections subjected to internal pressure. A comparison with a series of full-scale experiments was conducted to verify the accuracy and reliability of the finite element analysis. Furthermore, three predictive equations were evaluated using the test data, and the Klever equation was concluded to give the most accurate prediction of burst strength. The finite element analysis was then extended to study the effects of major factors on the casing burst strength. Results showed that the initial eccentricity and material hardening parameter had important effects on the burst strength, while the effect of the initial ovality was small.

High Temperature Design of PVP Bolted Flanged Joints

2010 ◽  
Author(s):  
Warren Brown
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Temperature ◽  
Design Codes ◽  
Element Analysis ◽  
Computing Power ◽  
Starting Point ◽  
Linear Creep ◽  
Initial Starting ◽  
Creep Problem

This paper presents a summary of the principal findings of a recent ASME sponsored study into the analysis methods used for high temperature flanges. The intent of the project was to examine the requirements for high temperature flange design and provide guidance for inclusion of design methods into the modern ASME pressure vessel design codes. Throughout the project, it was kept in mind that high temperature flange joints are a relatively small portion of the flange population, and that improvements in Finite Element Analysis (FEA) and computing power are now to the point where very large non-linear creep problems can be solved relatively easily. Therefore, while the fundamentals of high temperature flange design using code equations were included in the assessment, the initial starting point for the project was to formulate guidelines for FEA of the creep problem, based on comparison with relatively scarce flange creep test data.

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