The Full Scale Burst Test of Large Diameter, High Pressure Gas Pipelines

Two example onshore gas pipelines were designed using a reliability-based approach. The first example (1219 mm, 17.2 MPa) represents a high-pressure large-diameter pipeline; the second example has a smaller diameter (762 mm) and lower pressure (9.9 MPa). Three steel grades (X70, X80 and X100) were used to develop three design solutions for each example. The wall thickness-related life cycle costs of the designs were evaluated. The design outcomes show that the reliability targets for both examples can be met using X100 steels and high equivalent design factors (0.93 for the first example and 0.9 for the second example). Moreover, ruptures and excessive plastic deformation of a defect free pipe were found to be insignificant integrity threats even when the design uses X100 and relatively high equivalent design factors such as 0.85 and 0.9. The economic assessment results show that the X100 design is the most economical option for the high-pressure large-diameter example. However, using X100 does not show a clear economic advantage over using X80 for the second example mainly because the wall thickness for the design using X100 is governed by the maximum D/t ratio constraint. The study also demonstrates the advantages of the reliability-based approach as a valuable tool in assessing the feasibility and potential benefits of using high-grade steels on a pipeline project.

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PREDICTION OF CONDENSATE FLOW RATES IN LARGE DIAMETER HIGH PRESSURE WET GAS PIPELINES

The APPEA Journal ◽

10.1071/aj77022 ◽

1978 ◽

Vol 18 (1) ◽

pp. 171 ◽

Cited By ~ 1

Author(s):

R. S. Cunliffe

Keyword(s):

High Pressure ◽

Residence Time ◽

Flow Rate ◽

Large Diameter ◽

Operating Pressure ◽

Gas Pipelines ◽

Liquid Holdup ◽

Wet Gas ◽

Exploration And Production ◽

Demand Changes

Esso Australia Ltd. operates two offshore gas platforms for Esso Exploration and Production Australia Inc. and Hematite Petroleum Pty. Ltd. in the Gippsland Basin. Gas and condensate from the Marlin platform flow to the gas plant near Sale, Victoria through a 67 mile, 20 inch pipeline. Gas and condensate from the Barracouta platform flow to the plant through a 30 mile, 18 inch pipeline. Average flowing pressure is 1300 psig. Condensate: gas ratios are 65 bbl/MMscf for Marlin and 15 bbl/MMscf for Barracouta.As these platforms are the only source of supply for the city of Melbourne, gas rates are changed to match gas demand. Changes in gas rate are accompanied by changes in condensate flow. From consideration of liquid holdup and liquid residence time, a method of predicting the condensate flow rate resulting from gas rate change was developed.A controlled run was made to test the prediction. After holding the Marlin gas rate steady at 150 MMscfd for 50 hours to reach equilibrium holdup conditions, the rate was increased to 250 MMscfd and held at this rate for 26 hours to reach equilibrium conditions again. The condensate flow rate out of the pipeline was monitored continually.The Marlin pipeline test demonstrated that changes in condensate flow rate resulting from changes in gas rate in high pressure wet gas pipelines can be predicted within 15 per cent of actual rates using liquid holdup and liquid residence time as input data. In the absence of holdup data from pipeline pigging, Eaton's correlation will provide good values for holdup for wet gas pipelines with operating pressure up to 1500 psig and which traverse relatively flat topography.This work has application in the sizing of liquid surge capacity required to receive condensate from high pressure wet gas pipelines. In many cases, investment in slug catcher facilities can be greatly reduced without risk of overfilling with liquid.

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Simulation of Dynamic Crack Propagation and Arrest Using Various Types of Crack Arrestor

Volume 3: Operations, Monitoring and Maintenance; Materials and Joining ◽

10.1115/ipc2016-64561 ◽

2016 ◽

Author(s):

Mohammed Uddin ◽

Gery Wilkowski

Keyword(s):

Crack Propagation ◽

Large Diameter ◽

Small Diameter ◽

Full Scale ◽

Fe Model ◽

Ductile Crack ◽

Burst Test ◽

Ductile Crack Growth ◽

Diameter Pipe ◽

Linepipe Steels

In linepipe steels, there has been a growing interest in using damage mechanics that provides physical models of the fracture process which are embedded into a two- or three-dimensional finite element (FE) model. Among the various damage models, the cohesive zone model (CZM) has recently been used to simulate the ductile crack growth behavior in linepipe steels because of its computational efficiency and it requires only two parameters which can be determined in experiments. While CZM is not yet to be used as predictive tool, but it has a great application in crack arrestor design as well as in providing insight to ductile crack propagation. In this paper, the authors have demonstrated some practical applications of CZM in linepipe steels. The CZM was used to simulate the ductile crack propagation in full-scale pipes which was able to capture the global deformation as well as the experimental crack speed. The model was then used to determine the effect of anchor blocks at the end of the pipe in a large diameter full-scale burst test. Later, the model was used to simulate two small diameter pipe tests with steel crack arrestors to mimic two arrestor cases with one showing crack propagation and the other showing crack arrest. The CZM model was also applied to demonstrate the circumferential ring-off behavior of a small diameter pipe test with rigid crack arrestor. The arrestor model was then extended to simulate a large diameter full scale Mojave burst test with “soft crack arrestor (SCA)”. A single element FE model was developed to verify the SCA material which was later extended with stain-based failure criteria. Finally, ductile crack growth in full-scale pipe with SCA was demonstrated to show that the FE CZM model can be used to optimize the design of SCA.

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Towards a Numerical Design Tool for Composite Crack Arrestors on High Pressure Gas Pipelines

2010 8th International Pipeline Conference, Volume 2 ◽

10.1115/ipc2010-31191 ◽

2010 ◽

Author(s):

F. Van den Abeele ◽

L. Amlung ◽

M. Di Biagio ◽

S. Zimmermann

Keyword(s):

High Pressure ◽

Large Scale ◽

Steel Wire ◽

Large Diameter ◽

High Strength ◽

Tensile Tests ◽

Design Tool ◽

Pipe Material ◽

Gas Pipelines ◽

Numerical Design

One of the major challenges in the design of ultra high grade (X100) high pressure gas pipelines is the identification of a reliable crack propagation strategy. Ductile fracture propagation is an event that involves the whole pipeline and all its components, including valves, fittings, flanges and bends. Recent research results have shown that the newly developed high strength large diameter gas pipelines, when operated at severe conditions (rich gas, low temperatures, high pressure), may not be able to arrest a running ductile crack through pipe material properties. Hence, the use of crack arrestors is required in the design of safe and reliable pipeline systems. A conventional crack arrestor can be a high toughness pipe insert, or a local joint with higher wall thickness. Steel wire wrappings, cast iron clamps or steel sleeves are commonly used non-integral solutions. Recently, composite crack arrestors have enjoyed increasing interest from the industry as a straightforward solution to stop running ductile cracks. A composite crack arrestor is made of (glass) fibres, dipped in a resin bath and wound onto the pipe wall in a variety of orientations. In this paper, the numerical design of composite crack arrestors will be presented. First, the properties of unidirectional glass fibre reinforced epoxy are measured and the micromechanic modelling of composite materials is addressed. Then, the in-use behaviour of pipe joints with composite crack arrestors is covered. Large-scale tensile tests and four point bending tests are performed and compared with finite element simulations. Subsequently, failure measures are introduced to predict the onset of composite material failure. At the end, the ability of composite crack arrestors to arrest a running fracture in a high pressure gas pipeline is assessed.

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Mechanical Development of a NPS 36 Speed Controlled Pipeline Corrosion Measurement Tool

Volume 1: Risk Assessment and Management; Emerging Issues and Innovative Projects; Operations and Maintenance; Corrosion and Integrity Management ◽

10.1115/ipc1998-2042 ◽

1998 ◽

Author(s):

Robert S. Evenson ◽

Scott K. Jacobs

Keyword(s):

High Pressure ◽

Natural Gas ◽

Large Diameter ◽

Speed Control ◽

Measurement Tool ◽

Gas Pipelines ◽

Natural Gas Pipelines ◽

Natural Gas Pipeline ◽

System A ◽

Flux Leakage

High pressure natural gas pipeline companies conducting in-line magnetic flux leakage (MFL) corrosion inspection operations had to significantly reduce gas throughput velocity to accommodate MFL corrosion tool inspection speeds. A large bypass, variable speed NPS 36 MFL corrosion inspection tool has been developed and run successfully in several high pressure natural gas pipelines without noticeable impact on operational throughput Active speed control enables the tool to run at speeds significantly lower than line velocity commonly experienced in high pressure natural gas pipelines. Unique mechanical innovations include large diameter flow bypass, an efficient speed control mechanism, variable drag backing bars and an independent bypass override system. A floating backing bar system ensures uniform sensor/wall contact for optimum data collection. Magnetic self-levitation of the backing bar results in reduced load on suspension and wheels providing more reliability and longer life to these components. Operating in higher line velocities infers higher possible tool speeds. This potential required development and construction of a more durable tool capable of higher speeds than typical MFL corrosion inspection tools. In this paper, development, testing and field operation of this tool is described.

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Full-Scale Burst Test of Hydrogen Gas X65 Pipeline

2010 8th International Pipeline Conference, Volume 2 ◽

10.1115/ipc2010-31235 ◽

2010 ◽

Cited By ~ 1

Author(s):

Shuji Aihara ◽

Hans I. Lange ◽

Kei Misawa ◽

Yasuhito Imai ◽

Yu Sedei ◽

...

Keyword(s):

Full Scale ◽

Hydrogen Gas ◽

Dynamic Crack Propagation ◽

Dynamic Crack ◽

Outer Diameter ◽

Pipe Material ◽

Gas Pipelines ◽

Static Tests ◽

Burst Test ◽

Resistance Curves

Full-scale burst test of X65 UOE linepipe, with 559mm outer diameter and 13.5mm wall thickness, pressurized at 16MPa by hydrogen gas was conducted. A 735mm long crack was introduced by explosive shaped charge over circumferential weld. The cracks were initiated and propagated in the both directions. The propagated crack lengths were 600mm and 270mm. J integral resistance curves were obtained from drop-weight as well as quasi static tests for the tested pipe material which was subjected to hydrogen charging. The tested steel showed little change in the resistance curves under realistic charging condition. Numerical simulation model of dynamic crack propagation, coupled with gas decompression behavior considering gas escape from opened crack, showed that an initiated crack was arrested at shorter distance in hydrogen gas pipelines than in methane gas pipelines, primarily due to earlier gas decompression in the former. The present results, together with the earlier full-scale burst tests conducted by the authors, demonstrated that hydrogen gas pipelines can be operated safely by using modern high-strength and high-toughness steel linepipes.

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Property of X80 Grade SAW Pipes for Resistance to Ground Movement

2008 7th International Pipeline Conference, Volume 3 ◽

10.1115/ipc2008-64512 ◽

2008 ◽

Cited By ~ 1

Author(s):

Izumi Takeuchi ◽

Masakazu Matsumura ◽

Shuji Okaguchi ◽

Hidenori Shitamoto ◽

Shusuke Fujita ◽

...

Keyword(s):

High Pressure ◽

Compressive Strain ◽

Large Diameter ◽

High Strength ◽

Axial Direction ◽

Primary Objective ◽

Ground Movement ◽

Gas Pipelines ◽

Long Distance ◽

Line Pipe

It is aware that the expansion of gas utilization is an important issue to restrict CO2 emission. The reduction of gas transportation cost is essential to increase gas supply to market. The high-pressure gas pipeline with high strength pipes has contributed for safe and economical transportation of natural gas and is expected more for the future demand of gas. The primary objective of high strength line pipe is to hold high pressure safely. The property in circumferential direction under hoop stress is the primary target of the line pipe. High strength and high toughness steel at low temperature has been developed for large diameter line pipes, which have been supplied to major gas pipelines. The increase of D/T of pipelines for transportation efficiency tends to decrease critical compressive strain. Since long distance pipelines come across various ground conditions, the pipeline might encounter some serious ground movement. It is pointed out that in this event the strain by the ground movement might be high enough to deform pipelines to leak or rupture. There are various forms of ground movement, but the Japanese guideline for earthquake resistance and liquefaction is considered as basic conditions for SBD and for FEA in this study. The relation between pipe deformation and property in axial direction is investigated to identify the effective parameter to design the steel property for gas pipelines. Metallurgical factors and microstructure can change the parameters not only on strength and toughness, but also on the critical strain of X80 line pipes. It is discussed that the effectiveness of those changes to improve the safe operation of high-pressure gas pipelines with X80 grade line pipe.

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Modified Two-Curve Model for Predicting Fracture Arrest Toughness and Arrest Distance of Full-Size Burst Tests

Volume 3: Operations, Monitoring and Maintenance; Materials and Joining ◽

10.1115/ipc2016-64585 ◽

2016 ◽

Author(s):

Xian-Kui Zhu

Keyword(s):

Test Data ◽

Pipeline Steel ◽

Large Diameter ◽

High Strength ◽

Full Scale ◽

Burst Test ◽

Pipe Segment ◽

Single Pipe ◽

Fracture Arrest ◽

Arrest Toughness

Running fracture control is a very important technology for gas transmission pipelines with large diameter and high pressure. The Battelle two-curve (BTC) model developed in the early 1970s has been widely used in pipeline industry to determine arrest toughness in terms of the Charpy energy. Because of its semi-empirical nature and calibration with test data only for grades up to X65, the BTC does not work for higher grades. Simple corrections were thus proposed to extend the BTC model to higher grades, but limited to those grades considered. Moreover, the BTC model only predicts the minimum arrest toughness, but not arrest distance. To fill the technical gaps, this paper proposes a modified two-curve (MTC) model and a fracture arrest distance model in reference to the Charpy energy. The MTC model coupling with an arrest distance algorithm can predict fracture arrest toughness and arrest distance in one simulation of numerical integration for a single pipe or a set of multiple pipes with given toughness. Two sets of full-scale burst test data for X70 and X80 are used to validate the proposed model, and the results show good agreements between the predictions and full-scale test data of arrest toughness and arrest distance as well. The MTC model is then applied to optimize a design of pipe segment arrangements for a mockup full-scale burst test on a high-strength pipeline steel. The MTC simulation results confirm the experimental observation that different pipe arrangements determine different arrest toughness and arrest distance for the same grade pipes.

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