Property of X80 Grade SAW Pipes for Resistance to Ground Movement

2008 ◽  
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.

Development of Heavy Gauge X70 Helical Line Pipe

2018 ◽  
Author(s):  
L. E. Collins ◽  
K. Dunnett ◽  
T. Hylton ◽  
A. Ray
Keyword(s):  
Low Temperature ◽  
Large Diameter ◽  
High Strength ◽  
Helical Line ◽  
Slab Thickness ◽  
Long Distance ◽  
Austenite Grain Size ◽  
Line Pipe ◽  
Nitrogen Levels ◽  
Low Temperature Toughness

A decade ago, the pipeline industry was actively exploring the use of high strength steels (X80 and greater) for long distance, large diameter pipelines operating at high pressures. However in recent years the industry has adopted a more conservative approach preferring to utilize well established X70 grade pipe in heavier wall thicknesses to accommodate the demand for increased operating pressures. In order to meet this demand, EVRAZ has undertaken a substantial upgrade of both its steelmaking and helical pipemaking facilities. The EVRAZ process is relatively unique employing electric arc furnace (EAF) steelmaking to melt scrap, coupled with Steckel mill rolling for the production of coil which is fed into helical DSAW pipe mills for the production of large diameter line pipe in lengths up to 80 feet. Prior to the upgrade production had been limited to a maximum finished wall thickness of ∼17 mm. The upgrades have included installation of vacuum de-gassing to reduce hydrogen and nitrogen levels, upgrading the caster to improve cast steel quality and allow production of thicker (250 mm) slabs, upgrades to the power trains on the mill stands to achieve greater rolling reductions, replacement of the laminar flow cooling system after rolling and installation of a downcoiler capable of coiling 25.4 mm X70 material. As well a new helical DSAW mill has been installed which is capable of producing large diameter pipe in thicknesses up to 25.4 mm. The installation of the equipment has provided both opportunities and challenges. Specific initiatives have sought to produce X70 line pipe in thicknesses up to 25.4 mm, improve low temperature toughness and expand the range of sour service grades available. This paper will focus on alloy design and rolling strategies to achieve high strength coupled with low temperature toughness. The role of improved centerline segregation control will be examined. The use of scrap as a feedstock to the EAF process results in relatively high nitrogen contents compared to blast furnace (BOF) operations. While nitrogen can be reduced to some extent by vacuum de-gassing, rolling practices must be designed to accommodate nitrogen levels of 60 ppm. Greater slab thickness allows greater total reduction, but heat removal considerations must be addressed in optimization of rolling schedules to achieve suitable microstructures to achieve both strength and toughness. This optimization requires definition of the reductions to be accomplished during roughing (recrystallization rolling to achieve a fine uniform austenite grain size) and finishing (pancaking to produce heavily deformed austenite) and specification of cooling rates and coiling temperatures subsequent to rolling to obtain suitable transformation microstructures. The successful process development will be discussed.

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

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.

Evaluation of Compressive Strain Limit of X80 Saw Pipes With Girth Welding by FE Analysis

2010 ◽  
Author(s):  
Hidenori Shitamoto ◽  
Masahiko Hamada ◽  
Shuji Okaguchi ◽  
Nobuaki Takahashi ◽  
Izumi Takeuchi ◽  
...  
Keyword(s):  
High Pressure ◽  
Natural Gas ◽  
High Strength ◽  
Environmental Conservation ◽  
Ground Movement ◽  
Bending Test ◽  
Line Pipe ◽  
Strain Capacity ◽  
Girth Welding ◽  
Transmission Pipelines

The expansion of supply capacity of natural gas to market is expected from the concern of environmental conservation by less CO2 emission. Transportation cost has been focused for natural gas to be competitive in the market. High-pressure gas pipelines have constructed by large diameter and high strength line pipes to improve transportation efficiency of gas transmission pipelines. High strength line pipes have been developed to cope with high-pressure operation. Strength in circumferential direction on line pipe is the prime target to hold high pressure safely. In terms of pipe size, pipe diameter has been increased to lead larger D/t. Both of higher strength and larger D/t result in less favorable to deformability of pipeline. To apply strain based design to pipeline, the evaluation of strain capacity, which is related to deformability of line pipe, is required supposing the pipeline encounters large scale ground movement such as earthquake or landslide. It is not simple to find the criteria to prevent leak or rupture of pipeline in such events, as not only pipe property but also interaction between pipe and soil are needed to consider. Gas transmission pipelines are constructed by joint girth welding. The strain capacity of pipeline with girth weld has to be investigated for strain based design. Full scale bending test of joint welded pipe was conducted and FEA model to assess strain capacity of pipeline with girth weld is developed.

Development of X80M Line Pipe Steel for Spiral Welded Pipes With Low Temperature Toughness and Excellent Weldability

2014 ◽  
Author(s):  
Nuria Sanchez ◽  
Özlem E. Güngör ◽  
Martin Liebeherr ◽  
Nenad Ilić
Keyword(s):  
Low Temperature ◽  
Life Cycle Cost ◽  
Volume Fraction ◽  
Large Diameter ◽  
Pipe Production ◽  
Strain Accumulation ◽  
Long Distance ◽  
Line Pipe ◽  
Low Temperature Toughness ◽  
Welded Pipe

The unique combination of high strength and low temperature toughness on heavy wall thickness coils allows higher operating pressures in large diameter spiral welded pipes and could represent a 10% reduction in life cycle cost on long distance gas pipe lines. One of the current processing routes for these high thickness grades is the thermo-mechanical controlled processing (TMCP) route, which critically depends on the austenite conditioning during hot forming at specific temperature in relation to the aimed metallurgical mechanisms (recrystallization, strain accumulation, phase transformation). Detailed mechanical and microstructural characterization on selected coils and pipes corresponding to the X80M grade in 24 mm thickness reveals that effective grain size and distribution together with the through thickness gradient are key parameters to control in order to ensure the adequate toughness of the material. Studies on the softening behavior revealed that the grain coarsening in the mid-thickness is related to a decrease of strain accumulation during hot rolling. It was also observed a toughness detrimental effect with the increment of the volume fraction of M/A (martensite/retained austenite) in the middle thickness of the coils, related to the cooling practice. Finally, submerged arc weldability for spiral welded pipe manufacturing was evaluated on coil skelp in 24 mm thickness. The investigations revealed the suitability of the material for spiral welded pipe production, preserving the tensile properties and maintaining acceptable toughness values in the heat-affected zone. The present study revealed that the adequate chemical alloying selection and processing control provide enhanced low temperature toughness on pipes with excellent weldability formed from hot rolled coils X80 grade in 24 mm thickness produced at ArcelorMittal Bremen.

TAP Project

2004 ◽  
Author(s):  
Carlo Maria Spinelli ◽  
Furio Marchersani
Keyword(s):  
High Pressure ◽  
High Strength Steel ◽  
High Strength ◽  
Innovation Activity ◽  
Long Distance ◽  
Gas Network ◽  
Research And Innovation ◽  
Gas Market ◽  
High Pressure Pipeline ◽  
Very High

International gas market development is towards very long transportation distances (3000–6000 km); the only suitable onshore technology to conjugate economics, large amount of gas conveyed and possibility to exploit remote gas fields appears to be the Very High Pressure (P > 14 MPa), Very High Strength Steel (Steel grade X100 API 5L [1] equivalent) option. Eni Group is going to sponsor a 3 years long project, called TAP (Trasporto gas Alta Pressione) [High Pressure gas Transportation] aimed to demonstrate: • economic evaluation; • technology reliability; • real possibility to build Very High Pressure Pipeline. The project itself is framed into five logical areas: • Evaluation of the applicability of alternative technological solution in extreme enterprise; • Technological innovation, mainly within Eni Group; • FEED (Front End Engineering Development) for strategic route gas pipeline and comparison with LNG option; • Demonstrative construction of a High Strength Steel (X80) pipeline section on Snam Rete Gas Network in Italy; • Demonstrative construction of a Very High Strength Steel (X100 API equivalent) provisioning pilot section pipeline. To achieve this object Eni has involved: • Eni Gas & Power Division as Business Developer; • Snamprogetti as Technology Developer; • Aquater, Enidata, Enitecnologie, Saipem, Snam Rete Gas as specific item expertises; • CSM and Universita` di Bergamo as high qualified partners for lab and full scale testing; • Pipe steel makers and coating producers as fundamental partners to develop new solutions. TAP, within Eni Group, is the final step of a long development research and innovation activity started 8 years ago with two explorative “Long distance pipeline High Grade Steel” projects on Very High Strength Steel performances (strength, toughness, weldability) carried out mainly with the support of Snam, Snamprogetti and Saipem. TAP final goal is to collect, transfer, develop all the possible technological solutions to be ready for building “The pipeline network for Very High Pressure Transportation”.

Buckling Resistance of Large Diameter Spiral Welded Linepipe

2004 ◽  
Author(s):  
Tom Zimmerman ◽  
Chris Timms ◽  
Jueren Xie ◽  
James Asante
Keyword(s):  
Oil And Gas ◽  
Weld Seam ◽  
Large Diameter ◽  
Ground Movement ◽  
Finite Element Analyses ◽  
Line Pipe ◽  
Diameter Pipe ◽  
Buckling Resistance ◽  
Analytical Research ◽  
Full Scale Tests

This paper contains the results of an experimental and analytical research program to determine the compressive buckling resistance of large-diameter, spiral-welded linepipe. Buckling resistance is important for pipe intended for service in Arctic, oil and gas pipeline systems, where pipes may be subjected to high bending strains caused by various ground movement events. The experimental work consisted of four full-scale tests of 30-inch (762 mm) diameter pipe subjected to various combinations of internal pressure, axial force and bending. The pipe specimens were fabricated using two material grades (X70 and X80) and two D/t ratios (82 and 48). Finite element analyses of the four tests were conducted to develop a better understanding of specimen behavior. The results suggest that spiral welded linepipe is as good as longitudinally welded line pipe in terms of buckling capacity. The spiral weld seam was in no way detrimental to the pipe performance.

Sour-Service Risers and Accessories for HP/HT Application in the Gulf of Mexico

2021 ◽  
Vol 73 (03) ◽  
pp. 60-61
Author(s):  
Judy Feder
Keyword(s):  
High Pressure ◽  
Yield Strength ◽  
Gulf Of Mexico ◽  
Wall Thickness ◽  
Large Diameter ◽  
High Strength ◽  
Thick Wall ◽  
Offshore Technology ◽  
Riser Pipe ◽  
Sour Service

This article, written by JPT Technology Editor Judy Feder, contains highlights of paper OTC 30558, “Development and Implementation of Heavy-Wall, High-Strength, Sour-Service Accessory and Risers for HP/HT Application in the Gulf of Mexico,” by Carine Landier, Jonathas Oliveira, and Christelle Gomes, Vallourec, et al., prepared for the 2020 Offshore Technology Conference, originally scheduled to be held in Houston, 4–7 May. The paper has not been peer reviewed. Copyright 2020 Offshore Technology Conference. Reproduced by permission. As oil and gas development in the Gulf of Mexico increasingly requires high-pressure/high-temperature (HP/HT) applications, the need for sour-service (SS) resistance also has grown. To meet these needs, continual innovation and improvement is needed in SS-grade materials from a technical and cost-effectiveness perspective. The complete paper discusses the material properties achieved with several large-diameter, heavy-wall SS pipes. The complete paper presents a detailed, illustrated discussion of the applications for the high-strength SS pipe and its manufacturing process. Applications The authors write that improved materials to meet HP/HT requirements such as those in the Gulf of Mexico are needed particularly for two applications: for risers, which require high-strength, thick-wall sour service; and as a substitute for corrosion-resistant alloy (CRA) with sour carbon material on defined accessories. Vallourec has developed high-strength [125,000-psi specified minimum yield strength (SMYS)] and resistant carbon steel pipes in sizes with outer diameter (OD) up to 23 in. and wall thickness up to 2.5 in. These sizes are common in lower-strength material, but meeting the high-pressure requirements with higher-grade material enables cost savings and eliminates some CRA components. It also enables the use of much-lighter-weight pipe than the 80,000-psi SMYS material that is standard for SS applications in oversize OD and heavy wall. Risers. Most deepwater drilling is performed with classic subsea blowout-preventer (BOP) systems. Access to the well through the BOP is accomplished with low-pressure, large-diameter (19-in. internal diameter) drilling riser pipe. Pipes are supplied in weldable grades (API 5L X65–X80). Large-diameter forged flanges are then welded onto the tubes. Connections are made by multiple bolts. High pressures, required as part of the drilling process, are supplied by small-diameter choke-and-kill lines. This system has served the industry well, but, as well pressures increase, so have cost and feasibility requirements of subsea BOP technology. These costs, driven by the complexity of redundant systems, have driven a desire to explore an alternative solution—a surface BOP with high-pressure drilling riser pipe. Using a surface BOP reduces the complexity and cost of the system significantly because of the ability to inspect it. The drilling riser then carries the pressure to the surface and must be able to contain it. The high-pressure environment that instigated a new solution was based on a 15,000-psi well pressure with NACE Region 2 SS performance. Because of the requirement for weldable grades for attaching the flange as well as SS, the maximum yield strength has been limited to 80,000 psi. At that strength, a very high wall thickness is required to meet 15,000 psi and greater. This becomes very heavy and can be limited by the rig hook-load capacity. Alternatives in weldable grades are nickel-based alloys with SS performance. A full string, however, is prohibitively expensive.

A Justification for Designing and Operating Pipelines Up to Stresses of 80% SMYS

2002 ◽  
Author(s):  
Martin McLamb ◽  
Phil Hopkins ◽  
Mark Marley ◽  
Maher Nessim
Keyword(s):  
Yield Strength ◽  
Oil And Gas ◽  
Large Diameter ◽  
Pipe Material ◽  
Gas Pipelines ◽  
Long Distance ◽  
Remote Locations ◽  
Pass Through ◽  
The Impact ◽  
Minimum Yield

Oil and gas majors are interested in several projects worldwide involving large diameter, long distance gas pipelines that pass through remote locations. Consequently, the majors are investigating the feasibility of operating pipelines of this type at stress levels up to and including 80% of the specified minimum yield strength (SMYS) of the pipe material. This paper summarises a study to investigate the impact upon safety, reliability and integrity of designing and operating pipelines to stresses up to 80% SMYS.

Hydrogen Compatibility and Suitability of (Ni)-Cr-Mo High-Strength Low-Alloy Seamless Line Pipe Steels for Pressure Vessels for Hydrogen Storage

2018 ◽  
Author(s):  
Akihide Nagao ◽  
Nobuyuki Ishikawa ◽  
Toshio Takano
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
High Strength ◽  
Pressure Vessels ◽  
Hydrogen Gas ◽  
Low Alloy Steels ◽  
Pipe Steels ◽  
Line Pipe ◽  
Alloy Steels ◽  
Pressure Hydrogen

Cr-Mo and Ni-Cr-Mo high-strength low-alloy steels are candidate materials for the storage of high-pressure hydrogen gas. Forging materials of these steels have been used for such an environment, while there has been a strong demand for a higher performance material with high resistance to hydrogen embrittlement at lower cost. Thus, mechanical properties of Cr-Mo and Ni-Cr-Mo steels made of quenched and tempered seamless pipes in high-pressure hydrogen gas up to 105 MPa were examined in this study. The mechanical properties were deteriorated in the presence of hydrogen that appeared in reduction in local elongation, decrease in fracture toughness and accelerated fatigue-crack growth rate, although the presence of hydrogen did not affect yield and ultimate tensile strengths and made little difference to the fatigue endurance limit. It is proposed that pressure vessels for the storage of gaseous hydrogen made of these seamless line pipe steels can be designed.

Tensile and Toughness Properties of Pipeline Girth Welds

2006 ◽  
Author(s):  
J. A. Gianetto ◽  
J. T. Bowker ◽  
R. Bouchard ◽  
D. V. Dorling ◽  
D. Horsley
Keyword(s):  
Weld Metal ◽  
Welding Process ◽  
Strain Curve ◽  
High Strength ◽  
Primary Objective ◽  
Stress Strain ◽  
Line Pipe ◽  
Arc Welding Process ◽  
Girth Welds ◽  
Metal Microstructure

The primary objective of this study was to develop a better understanding of all-weld-metal tensile testing using both round and strip tensile specimens in order to establish the variation of weld metal strength with respect to test specimen through-thickness position as well as the location around the circumference of a given girth weld. Results from a series of high strength pipeline girth welds have shown that there can be considerable differences in measured engineering 0.2% offset and 0.5% extension yield strengths using round and strip tensile specimens. To determine whether or not the specimen type influenced the observed stress-strain behaviour a series of tests were conducted on high strength X70, X80 and X100 line pipe steels and two double joint welds produced in X70 linepipe using a double-submerged-arc welding process. These results confirmed that the same form of stress-strain curve is obtained with both round and strip tensile specimens, although with the narrowest strip specimen slightly higher strengths were observed for the X70 and X100 linepipe steels. For the double joint welds the discontinuous stress-strain curves were observed for both the round and modified strip specimens. Tests conducted on the rolled X100 mechanized girth welds established that the round bar tensile specimens exhibited higher strength than the strip specimens. In addition, the trends for the split-strip specimens, which consistently exhibit lower strength for the specimen towards the OD and higher for the mid-thickness positioned specimen has also been confirmed. This further substantiates the through-thickness strength variation that has been observed in other X100 narrow gap welds. A second objective of this study was to provide an evaluation of the weld metal toughness and to characterize the weld metal microstructure for the series of mechanized girth welds examined.

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