Collapse Resistance Enhancement in UOE SAWL Line Pipes During Coating Heat Treatment for Ultra Deepwater Applications

2014 ◽  
Author(s):  
Fábio Arroyo ◽  
Harold R. León ◽  
Ronaldo Silva ◽  
Luciano Mantovano ◽  
Rafael F. Solano ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Large Diameter ◽  
Final Analysis ◽  
Material Strength ◽  
Line Pipe ◽  
Offshore Pipelines ◽  
Cold Forming ◽  
Collapse Resistance ◽  
Offshore Pipeline ◽  
Key Factor

Large diameter UOE pipes are being increasingly used for the construction of offshore pipelines and in the last few year, since oil discoveries are moving towards ultra-deepwater areas, such as Pre-Salt in Brazil, collapse resistance is a key factor in the design of the pipelines the demand for pipes with high thickness near the limits for fabrication and installation capacity. It is known that the cold forming, and the final expansion in the UOE line pipe manufacturing process, reduces the elastic limit of the steel in subsequent compression. Due to this, the DNV collapse formula includes a fabrication factor that de-rates by a 15% the yield strength of UOE Pipes. However, DNV also recognizes the effect of thermal treatments and the code allows for improvement of the fabrication factor when heat treatment or external cold sizing (compression) is applied, if documented. In previous work [1] it was presented the qualification of UOE pipes with enhanced collapse capacity focusing the use of a fabrication factor (alpha-fab) equal to 1. A technology qualification process according to international standard has been performed. The main aspects of the qualification process were presented and included significant material, full scale testing and final analysis. In this paper, we compare those results with the ones of the new qualification tests analyzing the more important variables affecting the collapse resistance such as ovality, compressive material strength, thermal treatment control, etc. This new qualification obtained even better results than the previous one, which will allow the use of a fabrication factor equal to 1 directly in deepwater and ultra-deepwater offshore pipeline projects with a possible reduction in material and offshore installation costs and also potentially enhancing the feasibility of many challenging offshore projects.

Qualification of UOE SAWL Linepipes With Enhanced Collapse Resistance for Ultra Deepwater Applications

2013 ◽  
Author(s):  
Fábio Arroyo ◽  
Rafael F. Solano ◽  
Luciano Mantovano ◽  
Fábio B. de Azevedo ◽  
Hélio Alves ◽  
...  
Keyword(s):  
New Technology ◽  
Large Diameter ◽  
Final Analysis ◽  
Load Testing ◽  
Offshore Pipelines ◽  
Cold Forming ◽  
Collapse Resistance ◽  
Offshore Pipeline ◽  
Key Factor ◽  
Combine Load

Large diameter UOE pipes are being increasingly used for the construction of offshore pipelines. Since oil discoveries are moving towards ultra-deepwater areas, such as Pre-Salt in Brazil, collapse resistance is a key factor in the design of the pipelines. It is known that the cold forming, and the final expansion in the UOE linepipe manufacturing process, reduces the elastic limit of the steel in subsequent compression. Due to this, the DNV collapse formula includes a fabrication factor that derates by a 15% the yield strength of UOE Pipes. However, DNV also recognizes the effect of thermal treatments and the code allows for improvement of the fabrication factor when heat treatment or external cold sizing (compression) is applied, if documented. This paper presents the qualification of UOE pipes with enhanced collapse capacity focusing the use of a fabrication factor (αfab) equal to 1. TenarisConfab has performed a technology qualification process according to DNV-RP-A203 standard “Qualification Procedures for New Technology”. The main aspects of the qualification process are presented in this paper which included significant material and full scale testing, including combine load testing, and final analysis. The qualification process achieved successful results and this will allow use of a fabrication factor equal to 1 directly in deepwater and ultra-deepwater offshore pipeline projects with a possible reduction in material and offshore installation costs and also potentially enhancing the feasibility of many challenging offshore projects.

Enhanced Collapse Resistance for Different D/t Ratios of UOE Pipes for Ultra Deepwater Application

2015 ◽  
Author(s):  
Rodrigo De Lucca ◽  
Rafael F. Solano ◽  
Doug Swanek ◽  
Fabio B. de Azevedo ◽  
Fábio Arroyo ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Cold Work ◽  
Large Diameter ◽  
Forming Process ◽  
Collapse Pressure ◽  
Processing Strategies ◽  
Collapse Resistance ◽  
Offshore Pipeline ◽  
Key Factor ◽  
Water Depths

Energy consumption outlook shows that the demand for Oil and Gas is increasing worldwide and since most of the undemanding reserves are already being explored, new reserves means longer distances from the shore and increasing water depths, of up to 3,000 meters. Collapse resistance has become a key factor in the design of pipelines for ultra-deepwater applications. UOE process is commonly used for manufacturing pipelines of large diameter and the cold work involved in this forming process modifies the mechanical properties of the pipes. This paper presents the effect of thermal treatment on final material properties, proving the validity of enhancing collapse for different D/t, as allowed by DNV-OS-F101 αFab, and extending what has been shown as valid on previous studies. In this work, the inputs for the processing strategies are presented, along with coupon compression testing and full scale testing, in order to qualify the selected route as compliant with producing pipes with αFab equal to 1, for usual D/t combinations. An analysis of the predicted collapse pressure compared to the real collapse pressure of the pipes is also presented. The extension of the qualification process achieved successful results and allows the use of a fabrication factor equal to 1 in ultra-deepwater offshore pipeline projects. This enables the reduction of wall thickness, generating reductions in material and offshore installation costs and also potentially enhancing the feasibility of many challenging offshore projects.

Methods for Collapse Pressure Prediction of UOE Linepipe

2006 ◽  
Author(s):  
Andreas Liessem ◽  
Ulrich Marewski ◽  
Johannes Groß-Weege ◽  
Gerhard Knauf
Keyword(s):  
Boundary Conditions ◽  
Large Diameter ◽  
External Pressure ◽  
Test Method ◽  
Future Research ◽  
Line Pipe ◽  
Cold Forming ◽  
Research Issues ◽  
Collapse Pressure ◽  
Strain Behavior

Line pipe intended for deep water applications has to be designed predominantly with regard to external pressure in order to avoid plastic collapse. As a consequence of cold forming during UOE pipe manufacture and the subsequent application of anticorrosion coating, the characteristic stress strain behavior has to be taken into account for a reliable prediction of the collapse pressure. Verification of collapse resistance of large diameter pipes against external pressure requires adequate and reliable component testing using a sufficient number of pipe samples. These samples have to be subjected to test conditions, which closely simulate the situation in service. As the test results may depend significantly on its boundary conditions, the results needs to be thoroughly analysed and compared with existing prediction methods. It is for these reasons that such full-scale testing is time-consuming and costly. The work presented in this paper aims at clarifying and quantifying the effect of existing test boundary conditions on the results of collapse tests (collapse pressures). Correlations will be established between material properties found in laboratory tests and associated component behavior. In this context it had been necessary to develop an accurate and reproducible compression test method. The actual collapse pressures and those predicted using current available equations are compared and verified by Finite Element calculations. The paper concludes with a discussion of the major findings and with a brief outlook to future research issues.

Offshore Pipeline Installation: 3-Dimensional Finite Element Modelling

2011 ◽  
Author(s):  
Lorenzo Marchionni ◽  
Lombardi Alessandro ◽  
Luigino Vitali
Keyword(s):  
Deep Water ◽  
Large Diameter ◽  
Fe Model ◽  
Offshore Pipelines ◽  
3 Dimensional ◽  
Deep Waters ◽  
Offshore Pipeline ◽  
Processing Program ◽  
Water Pipelines ◽  
Dimensional Finite Element

The future offshore pipeline development projects envisage the installation of medium to large diameter pipelines (16″ to 32″ ND) transporting gas from the deep waters to the shallow water areas. The development of these deep water projects is limited by the feasibility/economics of the construction phase using the J-lay or the S-lay technology. In particular, the S-lay feasibility depends on the applicable tension at the tensioner which is a function of water depth, stinger geometry (length and curvature), and installation criteria. In this paper: – The challenges of future deep water offshore pipelines are briefly presented; – The installation criteria at the overbend, stinger tip and sagbend are discussed; – The ABAQUS FE Model, developed to simulate pipeline installation, is presented together with the pre- and post-processing program put in place; – The results of the developed ABAQUS FE Model are given considering two typical examples of deep water pipelines installed in the S-lay mode.

On the Effect of the U-O-E Manufacturing Process on the Collapse Pressure of Long Tubes

1994 ◽  
Vol 116 (1) ◽  
pp. 93-100 ◽  
Author(s):  
S. Kyriakides ◽  
E. Corona ◽  
F. J. Fischer
Keyword(s):  
Manufacturing Process ◽  
Large Diameter ◽  
External Pressure ◽  
Cold Forming ◽  
Collapse Pressure ◽  
Circular Shape ◽  
Strain Behavior ◽  
Offshore Pipeline ◽  
Numerical Process ◽  
Two Stages

A commonly used process for manufacturing large-diameter tubes for offshore pipeline, riser and tension-leg platform tether applications involves the cold forming of long plates. The plates are bent into a circular shape and then welded. The circumference of the pipe is then plastically expanded to develop a high tolerance circular shape. Collectively, these steps comprise the U-O-E manufacturing process. These mechanical steps cause changes in the material properties and introduce residual stresses in the finished pipe. This paper presents the results of a combined experimental and analytical study of the effect on the U-O-E process on the capacity of the tube to resist collapse under external pressure loading. The U-O-E manufacturing process for a 26 in. (660 mm) diameter, 1.333 in. (33.86 mm) wall thickness pipe was simulated numerically. The numerical process was validated by comparing the predicted stress-strain behavior of the material at two stages in the process with properties measured from actual pipe specimens obtained from the mill. Following the simulation of the U-O-E process the collapse pressure was calculated numerically. The manufacturing process was found to significantly reduce the collapse pressure. A similar pipe for which the final sizing was conducted (simulated) with circumferential contraction (instead of expansion) was found not to have this degradation in collapse pressure.

Qualification of Enhanced Collapse Capacity UOE Deepwater Linepipe

2011 ◽  
Author(s):  
Simon Slater ◽  
Robin Devine ◽  
Olav Aamlid ◽  
David Hernandez ◽  
Doug Swanek
Keyword(s):  
Heat Treatment ◽  
Quality Control ◽  
Test Procedure ◽  
Local Buckling ◽  
Small Scale ◽  
Compression Tests ◽  
Forming Process ◽  
Pipe Length ◽  
Cold Forming ◽  
Collapse Resistance

The local buckling of pipelines under external pressure is comprehensively addressed in section 5 of DNV-OS-F101 Rules for Submarine Pipeline Systems. The equations used, calculate the plastic and elastic components to give an overall collapse pressure. These equations include factors that are controlled by the pipe manufacturer. A key feature of the collapse design formula is that the compressive yield stress of UOE pipes is de-rated by 15 per cent through the use of a fabrication factor, αfab. This de-rating is used to account for the Bauschinger effect caused by the pipe forming process, in particular the final expansion. It is well documented that the cold forming (compression & expansion) and light heat treatment can have a beneficial effect on the compressive strength, leading to higher fabrication factors for UOE linepipe. DNV-OS-F101 states, “The fabrication factor may be improved through heat treatment or external cold sizing (compression), if documented”. The standard does not specify what documentation or quality control is required at the pipe mill to ensure every pipe length has the same collapse resistance to allow the increase in fabrication factor. Tata Steel Tubes Europe (Energy), together with Williams Field Services and Det Norske Veritas have recently concluded a technology qualification process, according to DNV-RP-A203 (Qualification Procedures for new Technology), with the specific aim of detailing the documentation and Quality Control needed to satisfy the requirements of DNV OS F101. This would then allow the use of increased fabrication factors in deepwater linepipe design. A key part of the technology qualification was the an extensive testing program that included small-scale compression tests, full-scale collapse tests and the newly developed ring collapse test procedure, which can be utilised as part of the mill quality control system for more representative assessment of the collapse resistance of linepipe material. This paper presents the systematic qualification process; including pipe manufacture, quality control and verification. It also presents some of the key mill capability requirements for producing deepwater UOE linepipe and additional factors that should be considered when optimising for local buckling resistance. Using this approach collapse pressures of above 585bar were achieved for a 457mm diameter × 31.75mm UOE pipe, equivalent to installation depths of over 5000m.

scholarly journals The Effect of Spiral Cold-Bending Manufacturing Process on Pipeline Mechanical Behavior

2016 ◽  
Author(s):  
Giannoula Chatzopoulou ◽  
Gregory C. Sarvanis ◽  
Chrysanthi I. Papadaki ◽  
Spyros A. Karamanos
Keyword(s):  
Internal Pressure ◽  
Manufacturing Process ◽  
Numerical Models ◽  
Large Diameter ◽  
External Pressure ◽  
Forming Process ◽  
Cold Forming ◽  
Cold Bending ◽  
Offshore Pipeline ◽  
Bending Capacity

Large-diameter spiral-welded pipes are employed in demanding hydrocarbon pipeline applications, which require an efficient strain-based design framework. In the course of a large European project, numerical simulations on spiral-welded pipes are conducted to examine their bending deformation capacity in the presence of internal pressure referring to geohazard actions, as well as their capacity under external pressure for offshore applications in moderate deep water. Numerical models that simulate the manufacturing process (decoiling and spiral cold bending) are employed. Subsequently, the residual stresses due to cold bending are used to examine the capacity of pipe under external pressure and internally-pressurized bending. A parametric analysis is conducted to examine the effect of spiral cold forming process on the structural behavior of spiral welded pipes and the effect of internal pressure on bending capacity. The results from the present study support the argument that spiral-welded pipes can be used in demanding onshore and offshore pipeline applications.

Influence of Residual Stress on the HIC Resistance of High Frequency Induction Welded Pipes With Regard to Process-Specific Influencing Factors

2010 ◽  
Author(s):  
Joachim Kra¨geloh ◽  
Holger Brauer ◽  
Christoph Bosch
Keyword(s):  
Residual Stress ◽  
Influencing Factors ◽  
High Frequency ◽  
Negative Impact ◽  
Material Strength ◽  
Line Pipe ◽  
Cold Forming ◽  
Steel Coil ◽  
Sour Service ◽  
High Frequency Induction

Over the last decades an increase in the exploration and exploitation of impure oil and gas resources in remote environments under aggravated conditions has become necessary. This led to a growing demand for pipes with resistance to sour service conditions. Salzgitter Mannesmann Line Pipe has enhanced its product range of High-Frequency-Induction (HFI) welded pipes in recent years accordingly. In the process of HFI welding of pipes, forming roles bend steel coil into a pipe which is then welded together without any filler metal. This cold forming results in residual stress, depending on the diameter and wall thickness of the pipe. The current state of technology is based on the perception that this residual stress has an adverse effect on the resistance of line pipes to HIC, because it amplifies — or if it is sufficiently high — even triggers the onset of HIC. Aim of this paper is to study the influence of residual stress on the resistance in HFI welded pipes to HIC with regard to process-specific influencing factors. Four material strengths are selected for the tests. The first three material strengths (API 5L Grade from Grade B up to X65) are intentionally produced from non sour service material in order to obtain sufficient HIC damage. The highest material strength examined is a sour service material alternative to ascertain whether under optimal material conditions HIC indications can result solely from high residual stress. Plate and pipe segments are examined by means of the cross-sectioning method for longitudinal and circumferential residual stress at the process steps that influence the residual stress. A series of experiments under simulated residual stress to determine the HIC resistance of these pipe materials in NACE TM0284 test solution A is carried out using the four-point-bend test according to ASTM G 39, usually applied in sulphide stress cracking tests of line pipe steels. A characteristic HIC value, the crack area ratio CAR, is determined as a function of C and Mn content and residual stresses. To verify the results, FEM was used to model a test bar with the same geometry and to re-calculate the above-mentioned case. The results of these experiments combined with the supporting theoretical considerations and modelling prove that in the case of HFI welded line pipes, the residual stress induced by the process has no negative impact on the resistance of HFI welded pipes to HIC.

A Novel Alloying Concept for Thermo-Mechanical Hot-Rolled Strip for Large Diameter HTS (Helical Two Step) Line Pipe

2008 ◽  
Author(s):  
Sandrine Bremer ◽  
Volker Flaxa ◽  
Franz M. Knoop
Keyword(s):  
Acicular Ferrite ◽  
Large Diameter ◽  
High Strength ◽  
Carbon Equivalent ◽  
Material Strength ◽  
Rolled Strip ◽  
Low Carbon ◽  
Line Pipe ◽  
Processing Strategies ◽  
Product And Process

One of the major priorities of the research and development department of the Salzgitter Group is placed on the product and process optimisation of both approved conventional steel grades for line pipe application and novel high strength alloying concepts. With respect to reduced wall-thicknesses and higher operating pressures for gas transportation pipelines, the requirements for hot wide strip material are steadily increasing. Material strength can be increased either by grain refinement of the ferritic-pearlitic phase in combination with precipitation hardening or by replacing the ferrite-pearlite by an intermediate microstructure, so-called acicular ferrite. A low carbon content supports the formation of the microstructure desired and results in an improvement of the carbon equivalent. This acicular ferrite does not only raise the material strength but also improve low temperature toughness, weldability and workability. New processing routes based on the demands of novel alloying concepts have been developed in order to achieve the intermediate microstructure. In the following paper, two different alloying and processing strategies and the resulting mechanical properties and microstructures are described and illustrated.

Effect of Full- and Small-Scale Reeling Simulation on Mechanical Properties of Weldable 13Cr Seamless Line Pipe

2013 ◽  
Author(s):  
Hidenori Shitamoto ◽  
Nobuyuki Hisamune
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Oil And Gas ◽  
Small Scale ◽  
Line Pipe ◽  
Offshore Pipeline ◽  
Oil And Gas Pipelines ◽  
Before And After ◽  
Offshore Oil And Gas ◽  
Offshore Oil

There are several methods currently being used to install offshore oil and gas pipelines. The reel-lay process is fast and one of the most effective offshore pipeline installation methods for seamless, ERW, and UOE line pipes with outside diameters of 18 inches or less. In the case of the reel-laying method, line pipes are subjected to plastic deformation multiplication during reel-laying. It is thus important to understand the change of the mechanical properties of line pipes before and after reel-laying. Therefore, full-scale reeling (FSR) simulations and small-scale reeling (SSR) simulations are applied as evaluation tests for reel-laying. In this study, FSR simulations were performed to investigate the effect of cyclic deformation on the mechanical properties of weldable 13Cr seamless line pipes. Furthermore, SSR simulations were performed to compare the results obtained by FSR simulations.

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