scholarly journals Responding to a Northern Pipeline Challenge

2000 ◽  
Author(s):  
Terry J. Klatt
Keyword(s):  
Natural Gas ◽  
Liquefied Natural Gas ◽  
Gas Pipeline ◽  
Operating Pressure ◽  
Pipe Steels ◽  
Line Pipe ◽  
Natural Gas Pipeline ◽  
Construction Methods ◽  
Discontinuous Permafrost ◽  
Future Work

An 800-mile natural gas pipeline is being considered as part of an Alaskan liquefied natural gas (LNG) project. Concepts to maximize the pipeline’s value and minimize its cost are considered. The pipeline’s operating pressure has been synchronized with the LNG plant’s inlet pressure to achieve system efficiencies. Line pipe steels are optimized to address pressure, fracture and geotechnical issues. An advanced approach to designing and operating a gas pipeline in discontinuous permafrost is evaluated. Construction methods and strategies have been developed in areas such as trenching and winter construction. Finally, future work to further develop these concepts is identified.

A Study on Cold Region Pipeline Design Based on Full-Scale Experiment

2008 ◽  
Author(s):  
Toshiya Tanaka ◽  
Scott Haung ◽  
Masami Fukuda ◽  
Matthew T. Bray ◽  
Satoshi Akagawa
Keyword(s):  
Natural Gas ◽  
Field Measurements ◽  
Test Site ◽  
Full Scale ◽  
Lessons Learned ◽  
Gas Pipeline ◽  
Cold Region ◽  
Freezing And Thawing ◽  
Natural Gas Pipeline ◽  
Discontinuous Permafrost

One of the major technical challenges in constructing natural gas pipeline is how to cope with cold region pipeline engineering aspects caused by freezing and thawing of soil around the pipeline. A pipeline running through discontinuous permafrost is subject to the potential risk of an unacceptable deformation, which is caused by thaw settlement or frost heaving at the boundary of permafrost and non-permafrost. It is important for a design engineer to predict the behavior of soil-pipeline interaction and make an adequate assessment of safety of pipeline in such portion. Although extensive efforts have been made to document those aspects, relatively little research has been carried out to comprehensively study the behavior of pipeline in response to short- and long-term change of thermal and mechanical properties of permafrost. In order to understand the complex behavior of natural gas pipeline and surrounding soil in cold regions, a full-scale experimental gas pipeline was constructed near Fairbanks, Alaska and had been studied intensively. The research project was carried out from the year of 1999 to 2004 under the sponsorship of Japan Science and Technology. The changes of ground thermal regime, vertical movement of the pipeline and the induced bending stress in the pipes were studied. The research team including researchers from Japan and the U.S collected and analyzed the field measurements from the test site. In this paper, the major findings and lessons learned from the project will be presented together with the result of numerical simulations related to the experiment.

Pipe Length Limit Analysis to Tunnel Vertical Well of Natural Gas Pipeline

2013 ◽  
Vol 457-458 ◽  
pp. 633-638
Author(s):  
Xin Tian ◽  
Chi Yuan Ren
Keyword(s):  
Natural Gas ◽  
Stress Analysis ◽  
Wall Thickness ◽  
Gas Pipeline ◽  
Operating Conditions ◽  
Normal Operation ◽  
Tube Length ◽  
Operating Pressure ◽  
Pipe Length ◽  
Natural Gas Pipeline

In practical applications, often using natural gas pipeline through the pipe shaft way, so conditions for shaft pipe stress analysis has a very important practical significance and economic value, and limit the tube length calculation is one of the key issues. Take advantage of this stress analysis software, combined with program design, the shaft condition of the pipeline depth simulation. The results show that: gas pipeline tunnel shaft limit pipe length and pipe material, wall thickness and operating conditions are closely related, the greater the steel yield strength and wall thickness, the smaller the operating pressure, the longer the tube length limit. In the actual design pipeline crossing, it should fully take into account the limits of the tube length limit, the limit calculated under different conditions, to ensure the normal operation of gas pipelines provide pipeline reliability and economic benefits.

Buoyancy Control on the 56” Cross Island Gas Pipeline Project, Trinidad and Tobago

2006 ◽  
Author(s):  
Luis A. Hernandez
Keyword(s):  
Natural Gas ◽  
Trinidad And Tobago ◽  
Gas Pipeline ◽  
Alternative Methods ◽  
Temporary Work ◽  
Natural Gas Pipeline ◽  
Construction Methods ◽  
Construction Techniques ◽  
Pipeline Project ◽  
Buoyancy Control

The Cross Island Pipeline (CIP) consists of approximately 76.5 kilometers of 56-inch natural gas pipeline from Beachfield to Point Fortin and originally designed with a total of 2.8 kilometers of continuous concrete weight coat for buoyancy control. Alternate design and construction techniques were used to improve the efficiency of the pipeline construction methods used for the concrete coated sections. In areas where temporary work space was limited due to the crossing of foreign pipelines; or where induction bends were installed; or where the 56” pipeline closely paralleled existing pipelines, an alternate method of weighting had to be considered. Bechtel proposed alternative methods for buoyancy control such as installation of Concrete Strap-On Weights and the use of Geotextile Buoyancy Control Saddle Weights.

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