Development of a Double Joint Welding Procedure Specification for Fatigue Applications

2016 ◽  
Author(s):  
Israel Marines-Garcia ◽  
Emma Erezuma ◽  
Noe Mota-Solis ◽  
Philippe P. Darcis ◽  
Hector M. Quintanilla
Keyword(s):  
Structural Integrity ◽  
Oil And Gas ◽  
Fatigue Behavior ◽  
Fatigue Loading ◽  
Gas Recovery ◽  
X65 Steel ◽  
Steel Catenary Risers ◽  
Service Environments ◽  
Firing Line ◽  
Welding Procedure

One of the major concerns in terms of Structural Integrity for Steel Catenary Risers (SCR) or Fatigue Sensitive Flowlines (FSFL) consists on their strength to withstand dynamic loading along their service life. SCR and FSFL systems always experience more considerable fatigue loading due to floating structures adopted for deep and ultra-deep water oil and gas recovery, as well as for free spanning due to seabed geography and marine currents. In this context, a Double Joint (DJ) Welding Procedure Specification (WPS) has been developed to comply with stringent fatigue requirements, as well as to assess their actual fatigue behavior. The benefits of having DJ are: improving the installation time (S-lay, J-lay or reel-lay) having half of the welding joint performed out of the firing line and reducing the need of Field Joint Coating by two, which results on decreasing project’s cost. This DJ development is focused on a more productive WPS applicable for sour service environments and fatigue endurance requirements considering a Narrow Groove (NG) with J-Bevel design, STT® root pass, SAW for fill and cap passes in 1G welding position. The obtained WPS results are presented on an X65 Steel pipe grade, 273.1 mm OD and 25.4 mm WT.

Sour Environmentally Assisted Fatigue of Welded SCR Materials: Post-Weld Finishing Treatment Evaluation

2010 ◽  
Author(s):  
Philippe P. Darcis ◽  
Israel Marines-Garcia ◽  
Stephen J. Hudak ◽  
Mariano Armengol ◽  
Hector M. Quintanilla
Keyword(s):  
Oil And Gas ◽  
Fatigue Tests ◽  
Oil And Gas Development ◽  
Intermediate Scale ◽  
Fatigue Design ◽  
X65 Steel ◽  
Girth Welds ◽  
Welded Pipe ◽  
Welding Procedure ◽  
Brine Environment

The current work aims to point out the influence of sour brine environment on the fatigue resistance of welded SMLS (seamless) steel pipe used for design and fabrication of risers for oil and gas development. A C-Mn steel X65 pipe 10.75″ (273.1 mm) outside diameter (OD) and 25.4 mm wall thickness (WT) was chosen for this program. The Welding Procedure designed for girth welds manufacturing involved the use of Lincoln STT-GMAW™ process for the root pass and SAW process with twin wire configuration for the fill and cap passes. This welding procedure presents a special post-weld finishing treatment, which consist in flapping the inner and outer weld overfills to produce a flush profile between weld metal and outer/inner pipe surfaces. The experimental approach focused on quantifying the effect of H2S using a sour brine environment. For this purpose, intermediate-scale fatigue data in the sour brine environment, using full thickness’ strip specimens extracted from the welded SMLS (seamless) pipe, have been generated. Intermediate-scale fatigue tests in air have also been obtained to provide a baseline for comparison with the sour brine data. Those results have been compared with full-scale fatigue tests in air environment. Finally, results were statistically analyzed to determine which standard fatigue design curves best represent the measured S-N fatigue endurance in air and sour brine environments. Results were also compared with available literature and results on other seamless’ welded pipe of the same API 5L, Grade X65 steel in comparable environments.

Structural Integrity Control of Ageing Offshore Structures: Repairing and Strengthening With Grouted Connections

2013 ◽  
Author(s):  
S. M. S. M. K. Samarakoon ◽  
R. M. Chandima Ratnayake ◽  
S. A. S. C. Siriwardane
Keyword(s):  
Structural Integrity ◽  
Oil And Gas ◽  
Load Transfer ◽  
Fatigue Loading ◽  
Offshore Structures ◽  
Future Research ◽  
Offshore Platforms ◽  
Historical Evidence ◽  
Design Service Life ◽  
Pros And Cons

Structural integrity control (SIC) is an increasingly important element of offshore structures. Not only is it used in newly built and existing offshore structures (e.g. oil and gas (O&G) production & process facilities (P&PFs), wind turbine installations, etc.), but SIC is also essential for ageing offshore platforms which are subjected to an extension of their design service life. In these cases, SIC programs must be performed to assess the platforms. If any significant changes in structural integrity (SI) are discovered, then it is essential to implement an appropriate strengthening, modification and/or repair (SMR) plan. Currently, welded and grouted repairs are mostly used for SMR. Although a welded repair may typically restore a structure to its initial condition, if the damage is due to fatigue loading and welded repairs have been carried out, then historical evidence reveals that there is a high potential for the damage to reappear over time. On the other hand, mechanical connections are significantly heavier than grouted connections. Consequently, grouted repairs are widely used to provide additional strength, for instance, to handle situations such as preventing propagation of a dent or buckle, sleeved repairs, leg strengthening, clamped repair for load transfer, leak sealing and plugging, etc. This manuscript examines current developments in grouted connections and their comparative pros and cons in relation to welded or mechanical connections. It also provides recommendations for future research requirements to further develop SMR with grouted connections.

An Investigation of the Fatigue Performance of Riser Girth Welds

2008 ◽  
Vol 130 (1) ◽  
Author(s):  
Stephen J. Maddox ◽  
Julian B. Speck ◽  
G. Reza Razmjoo
Keyword(s):  
Oil And Gas ◽  
Welding Process ◽  
Fatigue Loading ◽  
Fatigue Tests ◽  
Fatigue Performance ◽  
Steel Catenary Riser ◽  
Gas Recovery ◽  
Fatigue Design ◽  
Pipeline Welding ◽  
Girth Welds

Increasing deep-water oil and gas recovery has highlighted the need for high integrity, high fatigue performance girth welds in steel catenary riser systems. Such systems include girth welds made from one side. However, the widely used fatigue design classification, UK Class F2, for such welds is not well founded, but probably overconservative for pipeline welds. In an attempt to justify upgrading current fatigue design classifications and providing a better basis for design, fatigue tests were performed on a range of girth-welded pipes produced by pipeline welding contractors. This paper presents the results of those tests and their evaluation in terms of the factors that influence the fatigue performance of girth welds, including welding process, welding position, backing system, joint alignment, weld quality, specimen type, and fatigue loading conditions. Conclusions are drawn regarding the scope for adopting higher design classifications and the conditions that must be met to justify them.

An Investigation of the Fatigue Performance of Riser Girth Welds

2006 ◽  
Author(s):  
Stephen J. Maddox ◽  
Julian B. Speck ◽  
G. Reza Razmjoo
Keyword(s):  
Oil And Gas ◽  
Welding Process ◽  
Fatigue Loading ◽  
Fatigue Tests ◽  
Fatigue Performance ◽  
Steel Catenary Riser ◽  
Gas Recovery ◽  
Fatigue Design ◽  
Pipeline Welding ◽  
Girth Welds

Increasing deep-water oil and gas recovery has highlighted the need for high integrity, high fatigue performance girth welds in steel catenary riser systems. Such systems include girth welds made from one side. However, the widely used fatigue design classification, UK Class F2, for such welds is not well founded, but probably over-conservative for pipeline welds. In an attempt to justify upgrading current fatigue design classifications and providing a better basis for design, fatigue tests were performed on a range of girth-welded pipes produced by pipeline welding contractors. This paper presents the results of those tests and their evaluation in terms of the factors that influence the fatigue performance of girth welds, including welding process, welding position, backing system, joint alignment, weld quality, specimen type and fatigue loading conditions. Conclusions are drawn regarding the scope for adopting higher design classifications and the conditions that must be met to justify them.

scholarly journals Management of Airframe In-Service Pitting Corrosion by Decoupling Fatigue and Environment

2021 ◽  
Vol 2 (3) ◽  
pp. 493-511
Author(s):  
Loris Molent ◽  
Russell Wanhill
Keyword(s):  
Corrosion Fatigue ◽  
Pitting Corrosion ◽  
Structural Integrity ◽  
Corrosion Damage ◽  
Fatigue Loading ◽  
Cost Driver ◽  
Service Environments ◽  
Corrosion Pits ◽  
The Impact ◽  
Fatigue Corrosion

Corrosion-induced maintenance is a significant cost driver and availability degrader for aircraft structures. Although well-established analyses enable assessing the corrosion impact on structural integrity, this is not the case for fatigue nucleation and crack growth. This forces fleet managers to directly address detected corrosion to maintain flight safety. Corrosion damage occurs despite protection systems, which inevitably degrade. In particular, pitting corrosion is a common potential source of fatigue. Corrosion pits are discontinuities whose metrics can be used to predict the impact on the fatigue lives of structural components. However, a damage tolerance (DT) approach would be more useful and flexible. A potential hindrance to DT has been the assumption that corrosion-induced fatigue nucleation transitions to corrosion fatigue, about which little is known for service environments. Fortunately, several sources indicate that corrosion fatigue is rare for aircraft, and corrosion is largely confined to ground situations because aircraft generally fly at altitudes with low temperature and humidity Thus, it is reasonable to propose the decoupling of corrosion from the in-flight dynamic (fatigue) loading. This paper presents information to support this proposition, and provides an example of how a DT approach can allow deferring corrosion maintenance to a more opportune time.

Influence of Fatigue Loading on the Engineering Critical Assessment of Steel Catenary Risers in Sour Deepwater Oil and Gas Developments

2009 ◽  
Vol 413-414 ◽  
pp. 313-325 ◽  
Author(s):  
Colum M. Holtam ◽  
David P. Baxter ◽  
Rachel C. Thomson ◽  
Ian A. Ashcroft
Keyword(s):  
Best Practice ◽  
Oil And Gas ◽  
Internal Surface ◽  
Fatigue Loading ◽  
Defect Tolerance ◽  
Tidal Motion ◽  
Failure Assessment ◽  
Steel Catenary Risers ◽  
Input Variables ◽  
Practice Methods

Steel catenary risers (SCR) are used in deepwater oil and gas developments to transfer produced fluids from the seabed to surface facilities. SCRs can be subject to fatigue loading from a variety of sources including wave and tidal motion, vortex induced vibration (VIV) and operating loads. When the produced fluids are sour (ie contain water and H2S) higher fatigue crack growth rates (FCGR) are expected, and this can have a significant effect on defect tolerance. The aim of this paper is to provide guidance on the current best practice methods for performing engineering critical assessments (ECA) on internal surface breaking defects in SCRs operating in a sour environment and subject to VIV fatigue loads. Example ECA calculations are presented for circumferential girth weld flaws, based on the failure assessment diagram (FAD) approach within the framework of BS 7910 [1]. The influence of certain key input variables is demonstrated, including the FCGR, determined from recent sour test data generated as part of this research.

Fatigue Behavior of API X-80 Steels

2012 ◽  
Author(s):  
Jaeki Kwon ◽  
Daeho Jeong ◽  
Inkyun Choi ◽  
Youngju Kim ◽  
Namsub Woo ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Sea Water ◽  
Fatigue Behavior ◽  
Fatigue Loading ◽  
Good Combination ◽  
Oil Well ◽  
Testing Conditions ◽  
Tidal Motion ◽  
R Ratio ◽  
Corrosive Environments

API X-80 steel is extensively used as a piping material in oil and gas industries with good combination of strength, toughness and resistance to H2S damage. Drill riser, for example, is a conduit providing a temporary extension of a subsea oil well to surface drilling facility and is in large part made of welded X-80 steel pipe. The riser system is subject to fatigue loading from wave and tidal motion, vortex induced vibration (VIV) and operating loads at low temperatures in corrosive environments. The reliability of drill riser system is extremely important and therefore the effects of environmental factors, including temperature and seawater, on fatigue crack propagation (FCP) behavior of X-80 steels, both BM (base metal) and WM (weld metal), need to be well understood. In this study, S-N fatigue and FCP tests were conducted on X-80 steel, including BM and WM, in air at 25 and −50°C and an R ratio of 0.1. The FCP tests were also performed on X-80 steel BM in artificial sea water at both cathodically and anodically controlled voltages. The fatigue behavior of X-80 steel at various testing conditions are discussed based on detailed optical micrographic and SEM fractographic observations.

scholarly journals Mode I Crack Propagation Experimental Analysis of Adhesive Bonded Joints Comprising Glass Fibre Composite Material under Impact and Constant Amplitude Fatigue Loading

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4380
Author(s):  
Alirio Andres Bautista Villamil ◽  
Juan Pablo Casas Rodriguez ◽  
Alicia Porras Holguin ◽  
Maribel Silva Barrera
Keyword(s):  
Crack Propagation ◽  
Structural Integrity ◽  
Crack Propagation Rate ◽  
Fatigue Loading ◽  
Propagation Rate ◽  
Operating Conditions ◽  
Impact Testing ◽  
Mode I ◽  
Mode I Crack ◽  
Constant Amplitude

The T-90 Calima is a low-wing monoplane aircraft. Its structure is mainly composed of different components of composite materials, which are mainly bonded by using adhesive joints of different thicknesses. The T-90 Calima is a trainer aircraft; thus, adverse operating conditions such as hard landings, which cause impact loads, may affect the structural integrity of aircrafts. As a result, in this study, the mode I crack propagation rate of a typical adhesive joint of the aircraft is estimated under impact and constant amplitude fatigue loading. To this end, effects of adhesive thickness on the mechanical performance of the joint under quasistatic loading conditions, impact and constant amplitude fatigue in double cantilever beam (DCB) specimens are experimentally investigated. Cyclic impact is induced using a drop-weight impact testing machine to obtain the crack propagation rate (da/dN) as a function of the maximum strain energy release rate (GImax) diagram; likewise, this diagram is also obtained under constant amplitude fatigue, and both diagrams are compared to determine the effect of each type of loading on the structural integrity of the joint. Results reveal that the crack propagation rate under impact fatigue is three orders of magnitude greater than that under constant amplitude fatigue.

scholarly journals New Glycerol Upgrading Processes

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 103
Author(s):  
Miguel Ladero
Keyword(s):  
Renewable Energy ◽  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Oil And Gas ◽  
The Other ◽  
Energy Policies ◽  
Gas Recovery ◽  
The Us ◽  
The Eu

Energy policies in the US and in the EU during the last decades have been focused on enhanced oil and gas recovery, including the so-called tertiary extraction or enhanced oil recovery (EOR), on one hand, and the development and implementation of renewable energy vectors, on the other, including biofuels as bioethanol (mainly in US and Brazil) and biodiesel (mainly in the EU) [...]

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