TurkStream Collapse Test Program

Author(s):  
Chris Timms ◽  
Doug Swanek ◽  
Duane DeGeer ◽  
Arjen Meijer ◽  
Ping Liu ◽  
...  

The TurkStream pipeline project is designed to transport approximately 32 billion cubic meters of natural gas annually from Russia to Turkey under the Black Sea, with more than 85% of the deep-water route being deeper than 2000 m. The offshore section is intended to consist of two parallel lines, each approximately 900 km long. The preliminary stages of the front end engineering design (pre-FEED) phase was managed by INTECSEA. To support the analyses and design of the deepest portions, a full scale collapse test program was performed by C-FER Technologies (C-FER). This collapse test program, which included 62 full-scale collapse and pressure+bend tests, 54 medium-scale ring collapse tests, and hundreds of small-scale tests, was primarily aimed at measuring, quantifying and documenting the increase in pipe strength and collapse resistance resulting from the thermal induction heat treatment effect (thermal ageing) that arises during the pipe coating process. Two grades of 32-inch (813 mm) outside diameter (OD) line-pipe, SAWL450 and SAWL485 with wall thicknesses of 39.0 mm or 37.4 mm, respectively, were supplied from various mills for testing. The collapse test program objectives were as follows: • Determine the collapse resistance of line pipes originating from various pipe mills; • Determine the pressure+bend performance of line pipes originating from various pipe mills; • Measure the effect of thermal ageing on material and collapse testing results, including the impact of multiple thermal cycles; and • Evaluate the results of medium-scale ring collapse tests as compared to full-scale tests. This paper presents selected results of this work, along with some comparisons to predictive equations.

Author(s):  
Luciano O. Mantovano ◽  
Mohamed R. Chebaro ◽  
Hugo A. Ernst ◽  
Marcos de Souza ◽  
Chris M. Timms ◽  
...  

The UOE-SAWL pipe manufacturing process introduces considerable plastic deformations and residual stresses to feedstock plate material. Previous experimental and analytical studies have demonstrated that the effects of this process, predominantly in its final expansion stage, significantly reduce the collapse resistance of deepwater linepipe. Finite element analyses, sensitivity analyses and full-scale tests were conducted by Tenaris and C-FER Technologies (C-FER) over the last several years to better comprehend the impact of cold forming on collapse resistance. This paper presents the findings of the latest segment of this ongoing study, the objective of which was to optimize the collapse resistance of UOE-SAWL linepipe by varying three key thermal ageing parameters: time, temperature and number of thermal cycles. Six X70M and four X80M UOE pipe samples were manufactured and thermally treated with varied parameters. Full-scale collapse and buckle propagation tests were then carried out in an experimental chamber that simulates deepwater conditions. These experimental results were evaluated with respect to collapse predictions from API RP 1111 and DNV OS-F101. Material and ring splitting tests were also performed on samples obtained from these pipes to better assess the extent of the UOE pipe collapse resistance recovery. The outcomes of this study will be employed to further optimize the collapse resistance of subsea linepipe in order to reduce material and offshore installation costs.


Author(s):  
Niels Kerstens ◽  
Ping Liu ◽  
Duane DeGeer

Comprising 4 pipelines over 900 km in length, with 32-in diameter and traversing water depths over 2200 m, the South Stream project requires a step-out in technology application. Following several years of preparation, the project is now approaching its implementation. In order to document the reliability of the collapse resistance for South Stream, an extensive material development program was initiated and executed, including small scale, medium scale, and full scale testing on over one hundred purposely manufactured pipe joints by world’s 5 leading mills. Testing performed included plate tests, full scale collapse tests on various combinations of plate sources, steel grades, and thermal ageing condition, pressure-bend tests, and reverse bending tests. A large number of medium and small scale tests were performed to allow the development of a suitably reliable statistical database for the probabilistic wall thickness design. In addition, programs were developed and executed for weldability tests, performing over one hundred trial welds, and for H2S resistance tests. This material development program was built on INTECSEA’s extensive experience with deep water large diameter pipelines (i.e. Oman-India, Blue Stream, Medgaz, Mardi Gras, IGI, etc.). Due to its extent and rigorous approach the South Stream material development program was able to conclusively prove the feasibility of the selected technological approach at an industrial scale. This paper provides an overview of the key design issues that were successfully addressed and the major technological advances that have been implemented as part of the linepipe material development process for deepwater pipelines in an H2S containing environment. The practical significance of this program is to optimize the wall thickness to a level that is manufacturable by the industry and hence enables the South Stream Project to proceed with its unprecedented depth and diameter combination.


Author(s):  
Andrew Cosham ◽  
Brian N. Leis ◽  
Mures Zarèa ◽  
Fabian Orth ◽  
Valerie Linton

Abstract A time-delayed failure due to stress-activated creep (cold-creep) will occur if the applied load is held constant at a level above the threshold. The results of small and full-scale tests on line pipe steels conducted by the Battelle Memorial Institute and the British Gas Corporation in the 1960s and 70s indicated that the (empirical) threshold for a time-delayed failure was approximately 85–95% SAPF (straight-away-pressure-to-failure). The line pipe steels were Grades X52 or X60, and the full-size equivalent Charpy V-notch impact energy (where reported) did not exceed 35 J. The strength and toughness of line pipe steels has significantly increased over the decades due to developments in steel-making and processing. The question then is whether an empirical threshold based on tests on lower strength and lower toughness steels is applicable to higher strength and higher toughness steels. A Tripartite Project was established to answer this question. The Australian Pipelines and Gas Association (APGA), the European Pipeline Research Group (EPRG) and the Pipeline Research Council International (PRCI) collaborated in conducting six full-scale step-load-hold tests on higher strength and higher toughness steels. Companion papers present the other aspects of this multi-year project. The line pipe supplied for testing is summarised below. • Identifier — Dimensions and Grade — f.s.e. Charpy V-notch impact energy at 0 C • APGA [A] — 457.0 × 9.1 mm, Grade X70M, ERW — 263 J • EPRG [E] — 1016.0 × 13.6 mm, Grade X70M, SAWL — 165 J • PRCI [P] — 609.6 × 6.4 mm, Grade X65, SAWL — 160 J Six step-load-hold tests, each with four part-through-wall defects, were conducted. Test Nos. APGA 1 and 2, and Nos. EPRG 1 and 2 were conducted at Engie, France. Test Nos. PRCI 1 and 2 were conducted at EWI, USA. The full-scale tests, and associated small-scale testing, are described and discussed. A time-delayed failure due to stress-activated creep occurred in each of the step-load-hold tests. The failures occurred during a hold-period at 93.7–104.4% SAPF, after a hold of approximately 1.0–13.9 hours. The results of the six step-load-hold tests are consistent with a threshold for a time-delayed failure of approximately 90% SAPF.


2011 ◽  
Vol 1 (32) ◽  
pp. 53
Author(s):  
Ian Ball ◽  
Edgar Mendoza-Baldwin ◽  
David Simmonds ◽  
Adrián Pedrozo-Acuña ◽  
Dominic E Reeve

In this paper we present laboratory observations of plunging wave breaker impact pressure responses on a steep coarse-grained beach, extending previous work conducted by Pedrozo-Acuña et al. (2008). Scale laboratory measurements of plunging breaker impact events are reported and compared with the previous full-scale tests. These tests extend the previous relationships to a wider range of surf-similarity parameters and indicate a continued reduction in impact pressure as the transition from plunging impacts to surging impacts is approached. Additional results from scale tests conducted on a smooth impermeable slope also indicate the presence of a maximum impact pressure within the plunging breaker region; however also suggest it may be necessary to include roughness and permeability in the parameterization of the impact pressure.


Author(s):  
Hans Olav Knagenhjelm ◽  
Oddvin O̸rjasæter ◽  
Per J. Haagensen

The Ormen Lange offshore pipelines from shore to the field go through very difficult terrain creating freespans in the range 40–80m for the 30” lines. For the 6” lines long freespans will be present prior to burial and vortex induced vibrations (VIV) will give a contribution during laying due to strong currents. Using existing codes for fatigue calculation was giving too conservative results compared to the welding technology used and experience from SCR work showed that better S-N data should be expected. A dedicated program was started as part of the Ormen Lange (OL) technology verification program overseen by Norwegian Authorities. An overview of the results is presented here. A full evaluation of the data is not yet complete. Papers will be published later presenting the full technical details and dataprocessing. Fatigue test results from the OL pipeline fatigue verification are presented focusing on the following topics: • Defect sizes in pipeline production welds; • Contractor-A: 5G welding position; • Contractor-B: 2G welding position; • 6” pipe full scale testing; • 30” pipe full scale testing; • Residual stresses; • Crack growth tests and sector specimen fatigue tests in production environments. The following are a summary of the main test variables in the program: • Mapping of actual welding defects compared to AUT results. • Welds with varying misalignment (high/low) and lack of penetration (LOP) from installation contractors tested in air. • Welds with natural welding defects in internal environment (Condensed water and formation water). • Welds with notches made by electrical discharge machining (EDM) (2×65mm and 2×15mm) in internal environment (condensed water and formation water). • Crack growth tests using large compact tension (CT) specimens in air, seawater and internal product environments (condensed water and formation water). • Full scale tests including worst case high/low, LOPs, and tests with normal welds including repair welds. The following main conclusions can be drawn from the work: • Small scale testing with representative worst case defects predicts well large scale testing results with the same features when the small scale specimen stresses are corrected for bending moments etc. arising from the cutout of the pipe. • Full scale testing of 30”×35.5mm wall thickness 2G pipes welded continuously (without start/stop) with worst case defects and high/low exceeds the D curve. • Full-scale tests of 30”×35.5mm wall thickness 5G non continuous welds with worst case defects and high/low exceeds the E curve. • Pipe welds showed low or even compressive residual stresses in the root. For continuously welded pipes the stress levels were low but more varying, also on the cap side. This partly explains the good results. • It is verified that the fatigue loads during operation are below the threshold of crack growth, and thus fatigue will not be a probable failure mechanism. This is under the condition that the measurements of vortex induced vibrations (VIV) during operation confirm the engineering calculations.


1988 ◽  
Vol 127 ◽  
Author(s):  
Hans G. Scheibel ◽  
V. Friehmelt ◽  
H. Froehlich

ABSTRACTThe fracture and release mechanism of radioactive aerosols of HLW glass and HLW canisters are studied experimentally by laboratory scale and full scale drop tests. The experimental conditions model the conditions of accidental drops in a deep salt repository. The laboratory scale drop tests have a scaling factor of 1:10. Accelerated probes of simulated HLW glass impact on a ground plate and the size distributions of broken fines and released aerosols are measured by sieving and scanning electron microscopy (SEM) of aerosol samples.The impact velocity is determined as the dominating impact parameter. Further parameters tested, such as waste glass composition, cooling time (residual thermal stresses), probe temperature at impact, and ground characteristics, show no measurable influence. Source terms of released respirable aerosols are evaluated for two reference cases, borehole drop (impact velocity v = 80 m/s) and reloading hall drop (v = 14 m/s), the values being 0.1 % and to 2.10-4 % respectively of the glass probe mass. The full scale drop tests are performed with European Standard HLW canisters. The canisters keep their integrity in all tests up to drop heights of 14 m. On opening the canisters, the broken fines are analyzed by sieving. The results are in good agreement with the small scale tests and confirm their acceptability for use in a safety analysis.


Author(s):  
Karl Christoph Meiwes ◽  
Susanne Höhler ◽  
Marion Erdelen-Peppler ◽  
Holger Brauer

During reel-laying repeated plastic strains are introduced into a pipeline which may affect strength properties and deformation capacity of the line pipe material. Conventionally the effect on the material is simulated by small-scale reeling simulation tests. For these, coupons are extracted from pipes that are loaded in tension and compression and thermally aged, if required. Afterwards, specimens for mechanical testing are machined from these coupons and tested according to the corresponding standards. Today customers often demand additional full-scale reeling simulation tests to assure that the structural pipe behavior meets the strain demands as well. Realistic deformations have to be introduced into a full-size pipe, followed by aging, sampling and mechanical testing comparable to small-scale reeling. In this report the fitness for use of a four-point-bending test rig for full-scale reeling simulation tests is demonstrated. Two high-frequency-induction (HFI) welded pipes of grade X65M (OD = 323.9 mm, WT = 15.9 mm) from Salzgitter Mannesmann Line Pipe GmbH (MLP) are bent with alternate loading. To investigate the influences of thermal aging from polymer-coating process one test pipe had been heat treated beforehand, in the same manner as if being PE-coated. After the tests mechanical test samples were machined out of the plastically strained pipes. A comparison of results from mechanical testing of material exposed to small- and full-scale reeling simulation is given. The results allow an evaluation of the pipe behavior as regards reeling ability and plastic deformation capacity.


2020 ◽  
Vol 8 (10) ◽  
pp. 759
Author(s):  
Mikko Suominen ◽  
Fang Li ◽  
Liangliang Lu ◽  
Pentti Kujala ◽  
Anriëtte Bekker ◽  
...  

Maneuvers in level ice are common operations for icebreakers and polar supply vessels. Maneuvering exposes the midship and stern area to ice interaction, influencing the magnitude and frequency of ice-induced loading in these areas. However, full-scale measurements do not typically cover the midship and stern areas, as measurements have commonly focused on the bow area. Controlled maneuvering tests were conducted during the ice trials of S.A. Agulhas II in the Baltic Sea. During these tests, ice-induced loading at different hull areas was measured simultaneously with ship control, navigation, and ice condition data. This work studied the effect of maneuvers on the characteristics and statistics of ice-induced loading at different hull areas and compared the impact to ahead operations. The study showed that the maneuvers had minor impact to the magnitude, frequency, and duration of loading at the bow and bow shoulder. On the other hand, maneuvers had a clear effect on the load magnitude and frequency at the stern shoulder. Additionally, a statistical analysis showed that the load magnitude increased as a function of load duration in all hull areas. Furthermore, the analyzed measurement data are presented and made available with the paper.


Author(s):  
James C. Kennedy

Light poles installed within the deflection zone of roadside barriers (guardrails) may influence the ability of the guardrail to safely redirect an impacting vehicle. One concern is that, during an impact, the vehicle may pivot about the relatively rigid light pole and then spin away from the guardrail back into the traffic stream in an uncontrolled, unsafe manner. A large percentage of the highway network in Ohio uses the type of guardrail and light pole configurations, in which the breakaway light poles are placed at either 15.2- or 45.7-cm (6- or 18-in.) lateral distance from the back of the guardrail, depending on one of two light pole base designs in use. These pole-guardrail systems were placed in large numbers some years ago and Ohio accident data have been inadequate to provide information to determine whether or not a problem exists with this system. Proposed highway rehabilitation and reconstruction projects can include changes or adjustments to placement of guardrails and light poles, but there was a lack of information as to whether or not the past practices possessed a problem. A study was conducted to determine if light poles have an adverse effect on the redirecting performance of guardrails. It included six full-scale crash tests involving two vehicle weight classes (2000P and 820C), two light pole base designs (AT-A and AT-X), and a typical guardrail used in Ohio [Type 5 (W-Beam)]. All full-scale tests were carried out according to the recommended procedures in National Cooperative Highway Research Program (NCHRP) Report 350. The actual vehicles used for the 2000P class were half-ton pickup trucks ballasted to simulate the weight and mass characteristics of the 2000P vehicle that is specified in NCHRP Report 350. The guardrail–light pole system was not shown to cause snagging or subsequent unstable motion of the vehicle due to impact. All vehicles exited the guardrail in a stable manner. No change in the arrangement of light poles behind the Type 5 guardrail is contemplated. The redirecting function of the guardrail was not compromised as a result of placement of the light pole behind the length-of-need. Excessive exit angle situations (according to NCHRP Report 350) occurred in three tests involving the simulated 2000P class vehicles. However, the impact conditions employed for these tests were extreme, and the likelihood of this situation occurring under everyday highway usage may be small.


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