Recent Development and Validation of the Latest FlawPRO™ ECA Methodology

2018 ◽  
Author(s):  
Bostjan Bezensek ◽  
Graham Chell ◽  
Carl Popelar ◽  
Meng Luo
Keyword(s):  
Test Data ◽  
Oil And Gas ◽  
Large Strain ◽  
Software Tool ◽  
Engineering Software ◽  
Property Data ◽  
Fracture Tests ◽  
Mechanics Concepts ◽  
Development And Validation ◽  
Pipeline Design

The graphical user interface driven engineering software tool FlawPRO™ has been extensively used for subsea pipeline design and installation under high strain or fatigue intense applications. The methodology included in the program has evolved since its inception in 2002 through a series of JIPs involving major oil and gas operators and installation contractors. This paper summarises the fracture mechanics concepts incorporated in the methodology of the latest version of FlawPRO™ and the results of an extensive full scale flawed pipe testing programme that included over 45 reeling simulations and other fracture tests performed to validate the methodology. It is shown that the program’s crack growth predictions under large strain reeling are consistent with test data obtained from reeled pipes containing centreline flaws in over-matched welds, with the majority of the predicted results obtained using average material property data scattering around the mean 1:1 line consistent with uncertainties in the mechanical property values used in the validation. The results of an assessment of some of the reeling test data using the DNV ECA methodology (DNV-RP-F108) are also presented. It is concluded that the FlawPRO™ methodology is consistently more accurate in assessing the test data compared with the DNV methodology which may yield some non-conservative results. Both methodologies require suitable factors of safety or adjustments to either material and / or load inputs to maintain conservatism in applications to the pipeline projects.

A Stochastic Analysis on the Effects of Restraint Component Characteristics on Injury Numbers at Frontal Crash Tests

2007 ◽  
Author(s):  
Taewung Kim ◽  
Hyungho Kim ◽  
Hyun-Yong Jeong ◽  
Wook Jin
Keyword(s):  
Standard Deviation ◽  
Test Data ◽  
Stochastic Analysis ◽  
Software Tool ◽  
Safety Performance ◽  
Crash Test ◽  
Engineering Software ◽  
Systems Model ◽  
Major Factors ◽  
Crash Tests

In general, crash test data have a comparatively large variation because of the complexity of the tests. However, only limited numbers of crash tests are usually conducted to assess the safety performance of a vehicle due to monetary and time limitation. Thus, it is necessary to control factors which cause the variation in the test data to have consistent crash test results and to correctly assess the safety performance of a vehicle under development. In this study, a MADYMO (MAthematical DYnamic MOdeling; an engineering software tool developed by TNO that allows users to design and optimize occupant safety systems) model was validated deterministically to result in similar head, chest, pelvis deceleration pulses and belt load pulses to those from tests, and it was also validated stochastically to result in similar mean and standard deviation values of HIC15 and 3 msec clip. By reducing the standard deviation of major factors which might cause the variation in the injury numbers, the reduced standard deviation of the injury numbers could be determined by conducting a stochastic analysis using the validated MADYMO model. The sensitivity of the standard deviation of the injury numbers to that of the major factors was calculated in order to determine the major factors which may cause the variation of the injury numbers the most. The sensitivity of the injury numbers implies that the variation in the air bag permeability and the critical load of the loadlimiter should be well controlled in order to reduce the variation in HIC15 and 3 msec clip, respectively.

Predictive Assessment of External Corrosion on Transmission Pipelines

2008 ◽  
Author(s):  
Gae¨l Pognonec ◽  
Vincent Gaschignard ◽  
Philippe Notarianni
Keyword(s):  
Growth Rate ◽  
Oil And Gas ◽  
Electrochemical Corrosion ◽  
Software Tool ◽  
Probability Of Failure ◽  
Entropy Method ◽  
Probabilistic Methods ◽  
Optimal Interval ◽  
Annual Probability ◽  
Cross Entropy Method

Oil and Gas operators have to deal with the ageing process of their transmission pipeline grid. Some of these pipelines can be inspected using In Line Inspection (ILI) tools. In order to maintain an acceptable integrity level, re-inspection operations have to be performed. This process needs to be optimized in terms of resources and cost. Gaz de France R&D Division has developed a methodology which prioritizes rehabilitation operations on a pipeline after in-line inspections, and determines the optimal interval for re-inspection. A reliable help decision software tool which applies the methodology has also been developed. Dealing with defects assimilated to external electrochemical corrosion, the developed methodology is based on: • pigs information in order to assess a probable corrosion growth rate; • probabilistic distribution of input parameters (geometrical characteristics of defects, characteristics of the pipe and corrosion growth rate); • probabilistic methods of calculation : the probability of failure is calculated with the Monte-Carlo method. The convergence of the calculation is accelerated with the Cross Entropy method. The calculation results take the form of three probabilities of failure: • a punctual probability of failure for each defect; • an annual probability of failure for each defect; • an annual probability of failure per kilometer of pipe. To interpret the results, the annual probability of failure per kilometer of pipe is then compared with threshold values.

Early Engagement of ECA in Offshore Deepwater Pipeline Design

2021 ◽  
Author(s):  
Daowu Zhou ◽  
Lingjun Cao ◽  
T. Sriskandarajah ◽  
Mark Lewis ◽  
Daniel Manso
Keyword(s):  
Oil And Gas ◽  
Fluid Composition ◽  
Acceptance Criteria ◽  
Gas Field ◽  
Detailed Design ◽  
Damage And Fracture ◽  
Weld Material ◽  
Challenging Environment ◽  
Oil And Gas Field ◽  
Pipeline Design

Abstract Welding acceptance criteria derived through ECA is typically performed after the detailed design. The design loads, together with pipeline and girth weld material testing data, are inputs to ECA and used to evaluate the pipeline girth weld integrity for determining the criticality of potential weld flaws. With ever increasing challenging environment (deepwater, HP/HT, aggressive fluid composition etc) in the oil and gas field, the fatigue damage and fracture failure may become a serious concern, consequently limiting the productivity of the pipeline fabrication. It is therefore essential to integrate ECA into the design loop to remove the uncertainty and risk to achieve a practically workable fabrication solution. In this paper, a strategy to integrate early ECA into pipeline detailed design phase is presented. A case study in a deepwater subsea channel crossing demonstrates that an early ECA engagement effectively mitigates the significant fatigue and fracture risk and obtains workable welding acceptance criteria for fabrication.

scholarly journals Effect of Gain in Soil Friction on the Walking Rate of Subsea Pipelines

2019 ◽  
Vol 7 (11) ◽  
pp. 401 ◽  
Author(s):  
Zhaohui Hong ◽  
Dengfeng Fu ◽  
Wenbin Liu ◽  
Zefeng Zhou ◽  
Yue Yan ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Pipeline System ◽  
Gas Industry ◽  
Steel Catenary Riser ◽  
Wide Range ◽  
Offshore Oil And Gas ◽  
Subsea Pipelines ◽  
Offshore Oil ◽  
Pipeline Design

Subsea pipelines are commonly employed in the offshore oil and gas industry to transport high-pressure and high-temperature (HPHT) hydrocarbons. The phenomenon of pipeline walking is a topic that has drawn a great deal of attention, and is related to the on-bottom stability of the pipeline, such as directional accumulation with respect to axial movement, which can threaten the security of the entire pipeline system. An accurate assessment of pipeline walking is therefore necessary for offshore pipeline design. This paper reports a comprehensive suite of numerical analyses investigating the performance of pipeline walking, with a focus on the effect of increasing axial soil resistance on walking rates. Three walking-driven modes (steel catenary riser (SCR) tension, downslope, and thermal transient) are considered, covering a wide range of influential parameters. The variation in walking rate with respect to the effect of increased soil friction is well reflected in the development of the effective axial force (EAF) profile. A method based on the previous analytical solution is proposed for predicting the accumulated walking rates throughout the entire service life, where the concept of equivalent soil friction is adopted.

From CAD to GIS to the Geoweb: A Natural Evolution

2010 ◽  
Author(s):  
Steve Adam
Keyword(s):  
Decision Making ◽  
Spatial Data ◽  
Oil And Gas ◽  
Spatial Information ◽  
Digital Data ◽  
Computer Hardware ◽  
Disruptive Technology ◽  
Data Sets ◽  
Spatial Data Sets ◽  
Pipeline Design

Computer hardware and software have played a significant role in supporting the design and maintenance of pipeline systems. CAD systems allowed designers and drafters to compile drawings and make edits at a pace unmatched by manual pen drawings. Although CAD continues to provide the environment for a lot of pipeline design, Geographic Information Systems (GIS) are also innovating pipeline design through routines such as automated alignment sheet generation. What we have seen over the past two or three decades is an evolution in how we manage the data and information required for decision making in pipeline design and system operation. CAD provided designers and engineers a rapid electronic method for capturing information in a drawing, editing it, and sharing it. As the amount of digital data available to users grows rapidly, CAD has been unable to adequately exploit data’s abundance and managing change in a CAD environment is cumbersome. GIS and spatial data management have proven to be the next evolution in situations where engineering, integrity, environmental, and other spatial data sets dominate the information required for design and operational decision making. It is conceivable that GIS too will crumble under the weight of its own data usage as centralized databases become larger and larger. The Geoweb is likely to emerge as the geospatial world’s evolution. The Geoweb implies the merging of spatial information with the abstract information that currently dominates the Internet. This paper and presentation will discuss this fascinating innovation, it’s force as a disruptive technology, and oil and gas applications.

scholarly journals Study of the Installation Process of the Subsea Tree Passed Through the Splash Zone

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1014
Author(s):  
Yufang Li ◽  
Honglin Zhao ◽  
Ning Xu ◽  
Xiaoyu Wang ◽  
Deguo Wang
Keyword(s):  
Wave Height ◽  
Oil And Gas ◽  
Splash Zone ◽  
Safety Standards ◽  
Engineering Software ◽  
Safe Production ◽  
Operational Safety ◽  
Offshore Oil And Gas ◽  
Marine Engineering ◽  
Offshore Oil

The subsea tree is one of the critical pieces of equipment in the subsea production system, and its installation is related to the safe production of offshore oil and gas. Due to the differences in the form of the structures, the speed of entering the water, the marine environment, and other factors, the process of the structure entering the water is exceedingly complicated. During the engineering installation, the most dangerous phase involves the structure passing through the splash zone. Based on the theory of the movement of the subsea tree passing through the splash zone, Lingshui 17-2 subsea tree installation was analyzed with the marine engineering software OrcaFlex, and a sensitivity analysis of the lowering of the subsea tree was performed. During the splash zone phase, the wave height had the highest impact on the subsea tree, affecting the horizontal offset and cable load, which may lead to the oil tree capsizing and cable breakage. Furthermore, the velocity only affected the horizontal offset, and the overall effect was not noticeable. The operational safety window for the subsea tree installation was established according to the operational safety standards. Therefore, the recommended lowering speed was 0.50 m/s, while the flow velocity should not exceed 1.50 m/s, and the wave height should not be higher than 4.5 m.

scholarly journals A Validation Study of the CEFR Levels of Phrasal Verbs in the English Vocabulary Profile

2012 ◽  
Vol 3 ◽  
Author(s):  
Masashi Negishi ◽  
Yukio Tono ◽  
Yoshihito Fujita
Keyword(s):  
Item Response Theory ◽  
Item Response ◽  
Test Data ◽  
Validation Study ◽  
Complex Relationship ◽  
Phrasal Verbs ◽  
Japanese Students ◽  
Previous Version ◽  
Phrasal Verb ◽  
Development And Validation

AbstractThis article reports on a part of the development and validation project for the English Vocabulary Profile (EVP). The previous version of the EVP included 439 phrasal verbs as well as 4,666 individual word entries. Each of their meanings is ordered according to its CEFR level. The aims of the study are to identify the actual difficulty of each phrasal verb, to validate the tentative decision of the CEFR levels, and also to explore factors that explain the difficulties, by using textbook corpora. In order to carry out this research, we developed a phrasal verb test of 100 items, consisting of four A1 items, nineteen A2 items, forty B1 items and thirty-seven B2 items. Approximately 1,600 Japanese students took this test. We analysed the test data, using item response theory. The results of the test show that although the average difficulties of the phrasal verbs in each level were ordered according to the level prediction, the ranges of the difficulties in each level overlapped. The analysis of textbook corpora reveals that there is a complex relationship between the difficulty levels of phrasal verbs and their frequencies in the textbooks. We discuss its implications and possible improvements for the EVP.

Fracture Toughness Testing and Validation of Pipeline Girth Weld Flaw Acceptance Criteria for Sour Service Under Large Strain

2011 ◽  
Author(s):  
You You Wu ◽  
Wen Guo Yuan ◽  
Tse Ven Steven Chong ◽  
Jens P. Tronskar
Keyword(s):  
Fracture Toughness ◽  
Oil And Gas ◽  
Large Strain ◽  
Axial Strain ◽  
Laboratory Data ◽  
Local Buckling ◽  
Acceptance Criteria ◽  
Service Environment ◽  
Girth Welds ◽  
Sour Service

Fracture toughness is one of the most important input parameters for assessment of pipeline girth weld failure capacity. For many new subsea pipeline projects there is a need to develop flaw acceptance criteria for pipeline installation considering the operation phase which may involve the transport of sour oil and gas and where the pipeline is exposed to large axial strain due to local buckling. Engineering Critical Assessment (ECA) performed using laboratory data based on conservative KISSC testing gives small acceptable flaw sizes which may be below the workmanship criteria for pipeline laying. DNV has conducted extensive research based on the requirements of DNV-OS-F101 and DNV-RP-F108, aiming to establish a method to develop J-R curves applicable for ECA of pipeline girth welds in sour service environment and a methodology to validate the ECA by segment testing in a laboratory-simulated sour service environment as per DNV-RP-F108.

Pipeline On-Bottom Stability Analysis Based on FEM Model

2011 ◽  
Author(s):  
Yong Bai ◽  
Zhimeng Yu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Design Procedure ◽  
Element Model ◽  
The Finite Element Method ◽  
Fem Model ◽  
Engineering Software ◽  
Calculation Results ◽  
Pipeline Design ◽  
Element Method

Pipeline on-bottom stability is one of the sophisticated problems in subsea pipeline design procedure. Due to the uncertainty of the pipe-soil interaction and environment loads, including wave, current, or earthquake, etc., it is classified as the typical nonlinear problem. The Finite Element Method is introduced into pipeline engineering several years ago. More and more special engineering software such as AGA, PONDUS are available in market. However, when doing a project, some abnormal data was found when compared the DnV calculation results and AGA. In order to know the behavior of pipeline on seabed under wave and current load, finite element method – ABAQUS is introduced to do this analysis. The ABAQUS/explicit is used to simulate 600s pipeline dynamic response. The pipeline is supposed to be exposed on seabed and the selected seabed model is large enough to avoid the edge effect. ABAQUS calculation results are compared with the requirements in DnV rules to verify the validity of finite element model.

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