Recent Concepts for the Welding of High Strain Pipelines

2009 ◽  
Author(s):  
Brian D. Newbury ◽  
Martin W. Hukle ◽  
Mark D. Crawford ◽  
Joshua Sleigh ◽  
Steven A. Altstadt ◽  
...  
Keyword(s):  
Large Scale ◽  
High Strain ◽  
Soil Liquefaction ◽  
Operating Pressure ◽  
Line Pipe ◽  
Strain Capacity ◽  
Soil Movement ◽  
Specific Material ◽  
Pipeline Design ◽  
Design And Testing

Standard allowable stress-based pipeline designs (strain demand ≤ 0.5%) are now giving way to more complex strain-based designs (strain demand higher than 0.5%) as the locations of future pipelines move into regions of increased strain demand. The increase in required levels of strain demand are attributed to seismic activity, soil movement, soil liquefaction, frost heave, thaw settlement, ice scour or a combination thereof. Pipelines in high strain demand regions are typically limited by the strain capacity of the girth weld. As strain-based pipeline design has matured, it has become evident that specific material properties (both weld metal and line pipe), defect size, defect location, misalignment, and operating pressure each affect the strain capacity of the pipeline. This paper reviews proposed design and testing methodologies for the qualification of strain-based design welding procedures. These methods have been applied in the development and qualification of welding procedures for the construction of pipelines subject to longitudinal tensile strains in excess of 2%. Strain-based design requires considerably more effort than traditional design in terms of girth weld qualification and testing. To ensure adequate girth weld strain capacity for strain-based design the testing includes large scale and full-scale pressurized testing for design validation.

Qualification of Welding Procedures for ExxonMobil High Strain Pipelines

2006 ◽  
Author(s):  
Martin W. Hukle ◽  
Douglas S. Hoyt ◽  
James B. LeBleu ◽  
John P. Dwyer ◽  
Agnes M. Horn
Keyword(s):  
Large Scale ◽  
High Strain ◽  
Soil Liquefaction ◽  
Critical Element ◽  
Test Program ◽  
Offshore Installations ◽  
Proof Testing ◽  
Girth Welds ◽  
Fault Displacement ◽  
Pipeline Design

Weld procedure qualification methodologies for ExxonMobil high strain pipelines are presented. ExxonMobil has been involved in the design and construction of high strain pipelines for both onshore and offshore applications. These projects have included onshore applications involving potential seismic activity (fault displacement and soil liquefaction) as well as arctic applications that may involve displacements associated with frost heave and thaw settlement. Recent offshore installations have been designed and constructed to accommodate potential displacement caused by ice scour. Some of these installations have been designed to accommodate in excess of 3% longitudinal tensile strain demand. A critical element of the overall pipeline design is the qualification and validation of acceptable strain capacity for the pipeline girth welds. A girth weld qualification test program, based on large scale proof testing (i.e., curved wide plates) has been developed and executed.

Strain-Based Pipeline Design in Harsh Environments Using Large Diameter High Strain Line Pipes

2014 ◽  
Author(s):  
Nobuhisa Suzuki ◽  
Takekazu Arakawa ◽  
Andrey Arabey
Keyword(s):  
High Strain ◽  
Large Diameter ◽  
Strain Curve ◽  
Bending Test ◽  
Harsh Environments ◽  
Standard Line ◽  
Stress Strain Curve ◽  
Line Pipe ◽  
Strain Capacity ◽  
Pipeline Design

This paper outlines the draft recommendations to be issued by Gazprom that deals with the advanced strain-based pipeline design to ensure pipeline integrity in harsh environments using stress-strain curve controlled high-strain line pipe (SSLP). The draft recommendations have been provided to employ the new design concept to some future pipeline projects. The analytical solution was adopted in the draft as the solution is useful to improve strain capacity by controlling the longitudinal tensile properties without increasing wall thickness. The concept was validated through full-scale bending test using X70, 1220 mm SSLPs. FEA clarified that the strain capacity in compression or bending of X70, 1420 mm SSLP, 9.8 MPa, is high compared to that of the standard line pipe (STLP). The strain demand required for the SSLP pipeline in the harsh environments shall be small compared to that for the STPL pipeline. The SSLP pipeline shall be beneficial for ensuring the pipeline integrity in the harsh environments.

Girth Weld Strength Matching Effect on Tensile Strain Capacity of Grade X70 High Strain Line Pipe

2018 ◽  
Author(s):  
Hisakazu Tajika ◽  
Takahiro Sakimoto ◽  
Tsunehisa Handa ◽  
Rinsei Ikeda ◽  
Joe Kondo
Keyword(s):  
High Strain ◽  
Limit State ◽  
Full Scale ◽  
Bending Test ◽  
High Grade ◽  
Line Pipe ◽  
Bending Tests ◽  
Strain Capacity ◽  
Pipeline Project ◽  
Pipe Bending

Recently high grade pipeline project have been planned in hostile environment like landslide in mountain area, liquefaction in reclaimed land or the frost heave in Polar Regions. Geohazards bring large scale ground deformation and effect on the varied pipeline to cause large deformation. Therefore, strain capacity is important for the pipeline and strain based design is also needed to keep gas transportation project in safe. High grade steel pipe for linepipe tends to have higher yield to tensile (Y/T) ratio and it has been investigated that the lower Y/T ratio of the material improves strain capacity in buckling and tensile limit state. In onshore pipeline project, pipe usually transported in 12 or 18m each and jointed in the field. Girth weld (GW) is indispensable so strength matching of girth weld towards pipe body is important. In this study strain capacity of Grade X70 high strain pipes with size of 36″ OD and 23mm WT was investigated with two types of experiments, which are full scale pipe bending tests and curved wide plate tests. The length of the specimen of full scale bending tests were approximately 8m and girth weld was made in the middle of joint length. A fixed internal pressure was applied during the bending test. Actual pipe situation in work was simulated and both circumferential and longitudinal stress occurred in this test. Test pipes were cut and welded, GTAW in first two layer and then finished by GMAW. In one pipe, YS-TS over-matching girth weld (OVM) joint was prepared considering the pipe body grade. For the other pipe, intentionally under-matching girth weld (UDM) joint was prepared. After the girth welding, elliptical EDM notch were installed in the GW HAZ as simulated weld defect. In both pipe bending tests, the buckling occurred in the pipe body at approximately 300mm apart from the GW and after that, deformation concentrated to buckling wrinkle. Test pipe breaking locations were different in the two tests. In OVM, tensile rupture occurred in pipe body on the backside of buckling wrinkle. In UDM, tensile rupture occurred from notch in the HAZ. In CWP test, breaking location was the HAZ notch. There were significant differences in CTOD growth in HAZ notch in these tests.

Seismic Integrity of High-Strain Cold Bend in Lateral Spreading Zone

2014 ◽  
Author(s):  
Nobuhisa Suzuki ◽  
Hidetaka Watanabe ◽  
Toshiyuki Mayumi ◽  
Hiroyuki Horikawa
Keyword(s):  
Residual Strain ◽  
High Strain ◽  
Peak Load ◽  
Local Buckling ◽  
Strain Curve ◽  
Lateral Spreading ◽  
Line Pipe ◽  
Strain Capacity ◽  
Cold Bending ◽  
Opening Mode

Excellent workability of the stress-strain curve controlled high strain line pipe on cold bending with a bending angle of 10 degrees is presented. The high-strain line pipe has a round-house type s-s curve with the stress ratio σ2.0/σ1.0 of 1.030, where σ1.0 and σ2.0 are 1.0% and 2.0% yield stress, respectively. A standard yield-plateau type line pipe was also employed for comparison. FEA was conducted to investigate the cold bending behaviors of X65, 24″ line pipe. The longitudinal strain induced in the high-strain pipe at peak load and unloaded steps are small compared to those in the standard pipe. Effects of residual strain on local buckling behaviors of the high-strain cold bends are investigated. The effect of residual strain on the strain capacity of cold bend subjected to closing and opening mode bending is small when the cold bend is not pressurized. FEA tends to overestimate the strain capacity in bending when the bend is pressurized. However FEA well predicts the locations of the shell wrinkle of the pressurized bend subjected to opening mode bending when residual strain is taken into account. Seismic integrity of the 24″ high-strain cold bend in a lateral spreading zone is demonstrated.

Strain Capacity of X100 High-Strain Linepipe for Strain-Based Design Application

2008 ◽  
Author(s):  
Satoshi Igi ◽  
Joe Kondo ◽  
Nobuhisa Suzuki ◽  
Joe Zhou ◽  
Da-Ming Duan
Keyword(s):  
Tensile Strain ◽  
Large Scale ◽  
High Strain ◽  
Compressive Strain ◽  
Local Buckling ◽  
Ground Movement ◽  
Frozen Ground ◽  
Long Distance ◽  
Element Analysis ◽  
Strain Capacity

In recent years, several natural gas pipeline projects have been planned for permafrost regions. Pipelines laid in such areas are subjected to large plastic deformation as a result of ground movement due to repeated thawing and freezing of the frozen ground. Likewise, in pipeline design methods, research on application of strain-based design as an alternative to the conventional stress-based design method has begun. Much effort has been devoted to the application of strain-based design to high strength linepipe materials. In order to verify the applicability of high-strain X100 linepipe to long distance transmission, a large-scale X100 pipeline was constructed using linepipe with an OD of 42″ and wall thickness of 14.3mm. This paper presents the results of experiments and Finite Element Analysis (FEA) focusing on the strain capacity of high-strain X100 linepipes. The critical compressive strain of X100 high-strain linepipes is discussed based on the results of FEA taking into account geometric imperfections. The critical tensile strain for high-strain X100 pipelines is obtained based on a curved wide plate (CWP) tensile test using specimens taken from girth welded joints. Specifically, the effect of external coating treatment on the strain capacity of X100 high-strain linepipe is investigated. The strain capacity of the 42″ X100 pipeline is considered by comparing the tensile strain limit obtained from girth weld fracture and critical compressive strain which occurs in local buckling under pure bending deformation.

A 3-Dimensional Continuum ALE Model for Soil-Pipe Interaction

2008 ◽  
Author(s):  
Abdelfettah Fredj ◽  
Aaron Dinovitzer ◽  
Joe Zhou
Keyword(s):  
Large Scale ◽  
Large Deformations ◽  
Ground Deformation ◽  
Ground Movement ◽  
Soil Movement ◽  
3 Dimensional ◽  
Ale Methods ◽  
Permanent Ground Deformation ◽  
Pipeline Design ◽  
Soil Pipe

Soil-pipe interactions when large ground movements occur are an important consideration in pipeline design, route selection, guide monitoring and reduce the risk of damage or failure. Large ground movement can be caused by slope failures, faulting, landslides and seismic activities. Such conditions induce large deformations of both the soil and pipe. Analyses of such behavior pose a significant challenge to capabilities of standard finite elements as the capability to analyze large deformations is required. This requirement is difficult to meet for Lagrangian-based code. New developments using ALE methods make it possible to determine soil and pipe deformation confidently for large displacements. This paper describes a study performed to investigate the mechanical behavior of a pipeline subjected to large soil movement. A 3D continuum modeling using an ALE (Arbitrary Eulerian Lagrangian) formulation was developed and run using LS-DYNA. The results are compared with published experimental data of large-scale test to verify the numerical analysis method. The analysis is further extended to analyze the soil-pipe interaction under permanent ground deformation such as those associated with surface fault rupture and landslides.

Strain Capacity Investigation on Grade X70 High Strain Line Pipe With Girth Weld

2018 ◽  
Author(s):  
Hisakazu Tajika ◽  
Takahiro Sakimoto ◽  
Tsunehisa Handa ◽  
Satoshi Igi ◽  
Rinsei Ikeda ◽  
...  
Keyword(s):  
High Strain ◽  
Compressive Strain ◽  
Bending Test ◽  
High Grade ◽  
Line Pipe ◽  
Strain Capacity ◽  
Global Strain ◽  
Significant Difference ◽  
Pipeline Project ◽  
Pipe Bending

Recently high grade pipeline project have been planned in hostile environment like landslide in mountain area, liquefaction in reclaimed land or the frost heave in Polar Regions. Geohazards bring large scale ground deformation and effect on the varied pipeline to cause large deformation. Therefore, strain capacity is important for the pipeline and strain based design is also needed to keep gas transportation project in safe. High grade steel pipe for linepipe tends to have higher yield to tensile (Y/T) ratio and it has been investigated that the lower Y/T ratio of the material improves strain capacity in buckling and tensile limit state. In onshore pipeline project, pipe usually transported in 12 or 18m each and jointed in the field. Girth weld (GW) is indispensable so strength matching of girth weld towards pipe body is important. In this study strain capacity of Grade X70 high strain pipe with size of 36” OD and 23mm WT was investigated with two types of experiments. One was a pipe bending test with whole pipe. The length of the specimen was approximately 8m and GW was made in the middle of joint length. A fixed internal pressure was applied during the bending test. Actual pipe situation in work was simulated and both circumferential and longitudinal stress occurred in this test. The other test was curved wide plate (CWP) test. In both tests, test pipes were cut and welded using GTAW in the first two layers and GMAW for the subsequent passes. Welding wire of TG-S62 and MG-S58P were used for GTAW and GMAW respectively to achieve over-matching girth weld considering the pipe body strength. Elliptical EDM notch was installed in the GW HAZ as simulated weld defect. In pipe bending test, buckling occurred at the intrados at 300 mm apart from the GW. 2D average compressive strain at buckling was 3.59% and this high compressive strain was considered to derive from the high strain capacity of this pipes. After the buckling, deformation concentrated to the buckling wrinkle. Test pipe broke at 35.5 degrees of pipe end rotation and the location was in base metal at the extrados opposite to the buckling wrinkle. The HAZ notch opened and CTOD was 1.44 mm and the global strain in 2D length average strain was 7.8%. In CWP test, tensile strain simply got large and pipe finally broke at global strain of 9.6% and CTOD of 15 mm. The break location was the HAZ notch. There was a significant difference in CTOD growth in HAZ between two test types. Conditions and factors that effect to these differences are argued in this paper.

Effect of Thermal Aging on Strain Capacity of X80 SAW Pipes

2012 ◽  
Author(s):  
Hidenori Shitamoto ◽  
Masahiko Hamada ◽  
Nobuaki Takahashi ◽  
Yuki Nishi
Keyword(s):  
Thermal Aging ◽  
Arc Welding ◽  
Submerged Arc Welding ◽  
Full Scale ◽  
Operating Pressure ◽  
Bending Tests ◽  
Strain Capacity ◽  
Submerged Arc ◽  
Pipe Bending

Application of API X80 grade line pipes has been promoted to increase the operating pressure. It is generally known that the deformability of submerged arc welding (SAW) pipes is decreased by increasing strength of the pipes. The assessment of the strain capacity of X80 SAW pipes is required for strain-based design (SBD). In the assessment of the strain capacity, one of the important issues is the effect of thermal aging during the anti-corrosion coating on the yielding phenomenon. In this study, full-scale pipe bending tests of X80 SAW pipes produced by UOE process were performed to evaluate the effect of thermal aging on the strain capacity.

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