Microstructure and Properties of Longitudinal Submerged Arc Welded Linepipes for Deep-Sea Pipeline

2014 ◽  
Vol 997 ◽  
pp. 409-414 ◽  
Author(s):  
Ji Xiang Gao ◽  
Lie Jun Li ◽  
Jian Feng Li ◽  
Xiao Ning Wang ◽  
Shao Jun Wei
Keyword(s):  
Deep Sea ◽  
Oil And Gas ◽  
Pipeline Steel ◽  
Test Methods ◽  
Granular Bainite ◽  
Thick Wall ◽  
Fine Crystal ◽  
Microstructure And Properties ◽  
Welded Pipe ◽  
Submerged Arc

This paper provides description of deep-sea JCOE process of longitudinal submerged-arc welded pipe.The test methods including optical microscopy and tensile,toughness,drop weight tear are applied, the microstructure and properties of deep-sea pipeline steel and deep longitudinal submerged arc welded pipe with thick wall are studied. The results indicates that pipeline steel of substrate organization to acicular ferrite mainly and deep with longitudinal submerged-arc welded thick wall pipe welding HAZ of rough crystal area and fine crystal area respectively main for granular bainite and associate polygon ferrite organization; Deep-sea LSAW steel pipe has reasonable control parameters for process, and its performance meets DNV-OS-F101:2007 specification and user project technology conditions,used for materiels of pipeline steel for China deep-sea oil and gas pipeline project.

Microstructure and Properties of Niobium Microalloyed Pipeline Steel in CSP and Steel Pipe Produced by ERW

2014 ◽  
Vol 1061-1062 ◽  
pp. 23-29
Author(s):  
Ji Xiang Gao ◽  
Lie Jun Li ◽  
Shao Jun Wei
Keyword(s):  
Oil And Gas ◽  
Production Control ◽  
Pipeline Steel ◽  
Steel Pipe ◽  
Electric Resistance ◽  
Microstructure And Properties ◽  
Electric Resistance Welding ◽  
Pipeline Project ◽  
Basic Characteristics ◽  
Strip Production

Based on the basic characteristics of Compact Strip Production (CSP), this paper studies the composition design of Nb micro-alloyed pipeline steel, proposed eliminating mixed grains production control technology, also studied the microstructure and properties of steel pipe produced by Electric Resistance Welding ( ERW). Its performance meets API 5L specification and the project technology conditions, used for materiel of steel pipe for oil and gas pipeline project.

Advanced submerged arc welding processes for Arctic structures and ice-going vessels

2016 ◽  
Vol 232 (1) ◽  
pp. 114-127
Author(s):  
Pavel Layus ◽  
Paul Kah ◽  
Viktor Gezha
Keyword(s):  
Case Studies ◽  
Arc Welding ◽  
Oil And Gas ◽  
Welding Process ◽  
Submerged Arc Welding ◽  
The Arctic ◽  
Correct Selection ◽  
Advantages And Disadvantages ◽  
Welding Processes ◽  
Submerged Arc

The Arctic region is expected to play an extremely prominent role in the future of the oil and gas industry as growing demand for natural resources leads to greater exploitation of a region that holds about 25% of the world’s oil and gas reserves. It has become clear that ensuring the necessary reliability of Arctic industrial structures is highly dependent on the welding processes used and the materials employed. The main challenge for welding in Arctic conditions is prevention of the formation of brittle fractures in the weld and base material. One mitigating solution to obtain sufficiently low-transition temperatures of the weld is use of a suitable welding process with properly selected parameters. This work provides a comprehensive review with experimental study of modified submerged arc welding processes used for Arctic applications, such as narrow gap welding, multi-wire welding, and welding with metal powder additions. Case studies covered in this article describe welding of Arctic steels such as X70 12.7-mm plate by multi-wire welding technique. Advanced submerged arc welding processes are compared in terms of deposition rate and welding process operational parameters, and the advantages and disadvantages of each process with respect to low-temperature environment applications are listed. This article contributes to the field by presenting a comprehensive state-of-the-art review and case studies of the most common submerged arc welding high deposition modifications. Each modification is reviewed in detail, facilitating understanding and assisting in correct selection of appropriate welding processes and process parameters.

Anisotropy of Mechanical Properties of API-X70 Spiral Welded Pipe Steels

2013 ◽  
Vol 753 ◽  
pp. 538-541 ◽  
Author(s):  
Haytham M. Al Jabr ◽  
John G. Speer ◽  
David K. Matlock ◽  
Peng Zhang ◽  
Sang Hyun Cho
Keyword(s):  
Rolling Direction ◽  
Charpy Impact ◽  
Charpy Impact Test ◽  
Impact Testing ◽  
Granular Bainite ◽  
Secondary Phases ◽  
Pronounced Increase ◽  
Ductile To Brittle Transition ◽  
Welded Pipe ◽  
Anisotropy Of Mechanical Properties

The effects of microstructure and texture on the toughness anisotropy of two API-X70 pipeline steels were investigated. One steel contained no nickel (0Ni) and the other contained 0.3 wt pct nickel (0.3Ni). Charpy V-notch impact testing was conducted on plate samples for both steels in three directions: longitudinal (L), transverse (T), and diagonal (D) with respect to the rolling direction. The microstructures of both steels were mixed and consisted of acicular ferrite, granular bainite, and small amounts of polygonal ferrite, with martensite-austenite and retained austenite islands as secondary phases. The ductile to brittle transition temperatures (DBTT) for the Charpy impact test were higher in the D direction for both plates, with a pronounced increase in the 0Ni steel. The anisotropy in toughness was mainly attributed to the crystallographic texture.

Study on the Characteristics of Well Completion Technology in Deepwater Oil and Gas Field Development

2021 ◽  
Vol 3 (8) ◽  
pp. 70-72
Author(s):  
Jianbo Hu ◽  
◽  
Yifeng Di ◽  
Qisheng Tang ◽  
Ren Wen ◽  
...  
Keyword(s):  
Deep Water ◽  
Deep Sea ◽  
Oil And Gas ◽  
Gas Field ◽  
Marine Research ◽  
Field Development ◽  
Research Technology ◽  
Well Completion ◽  
Development Capacity ◽  
Exploration And Development

In recent years, China has made certain achievements in shallow sea petroleum geological exploration and development, but the exploration of deep water areas is still in the initial stage, and the water depth in the South China Sea is generally 500 to 2000 meters, which is a deep water operation area. Although China has made some progress in the field of deep-water development of petroleum technology research, but compared with the international advanced countries in marine science and technology, there is a large gap, in the international competition is at a disadvantage, marine research technology and equipment is relatively backward, deep-sea resources exploration and development capacity is insufficient, high-end technology to foreign dependence. In order to better develop China's deep-sea oil and gas resources, it is necessary to strengthen the development of drilling and completion technology in the oil industry drilling engineering. This paper briefly describes the research overview, technical difficulties, design principles and main contents of the completion technology in deepwater drilling and completion engineering. It is expected to have some significance for the development of deepwater oil and gas fields in China.

The Development of Large Diameter and Thickness X80 HSAW Linepipe

2008 ◽  
Author(s):  
Weiwei Li ◽  
Chunyong Huo ◽  
Qiurong Ma ◽  
Yaorong Feng
Keyword(s):  
Bauschinger Effect ◽  
Pipeline Steel ◽  
Large Diameter ◽  
Base Material ◽  
Longitudinal Direction ◽  
Strength Loss ◽  
Ring Test ◽  
Low Carbon ◽  
Pipeline Project ◽  
Submerged Arc

For the requirement of 2nd West-East Pipeline Project of China, X80 large diameter & thickness linepipe with helical seam submerged arc welded (HSAW) were developed, with 1219 mm OD and 18.4 mm WT. Acicular ferrite type and super-low carbon, high Niobium chemical composition pipeline steel was adopted for the base material. The very stringent requirements at −10 °C for toughness, i.e. 220J/170J for average/minimum for pipe body and 80J/60J for average/minimum for weld and HAZ were meet successfully. The yield strength loss due to Bauschinger effect was found lower than 20MPa, which benefited. The very low residual stress level was testified by cut-ring test which cuts a section pipe about exceed 100mm long, and then cut the section apart from welds 100mm along the longitudinal direction.

Experimental Study of Fatigue Crack Overload Retardation in X80 Grade Steel

2008 ◽  
Author(s):  
Qingquan Duan ◽  
Hong Zhang ◽  
Feng Yan
Keyword(s):  
Fatigue Crack ◽  
Crack Growth ◽  
Oil And Gas ◽  
Prediction Models ◽  
Pipeline Steel ◽  
Compact Tension ◽  
X80 Pipeline Steel ◽  
Oil And Gas Pipelines ◽  
Crack Retardation ◽  
Grade Steel

The tests of fatigue crack overload retardation were performed to gain a some what deeper understanding of overload retardation. We present an experimental investigation of fatigue crack retardation behavior caused by intermediate single peak tensile overload under constant amplitude cyclic loading. The compact tension (CT) specimens of API grade X80 pipeline steel were used in fatigue test. The results show there was an instant crack extension during overloading for the tested overload ratios. As soon as the overload cycle was removed, instant delay in crack growth occurred. The results should be of interest for fracture mechanics prediction models on fatigue crack growth under variable amplitude loading and overloading effect for oil and gas pipelines.

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