Structural Design

The Industry Challenge

The CNG Optimum System, a compressed natural gas (CNG) containment carrier developed by Global Energy Ventures Ltd. (GEV), required approval from the American Bureau of Shipping (ABS) prior to commercial construction. This program was part of a larger project, which included the design of the ship on which the CNG Optimum System would be installed.  

As part of the CNG Optimum System approval process, testing was required to validate the fatigue resistance and burst...

Abstract

The Mardi Gras Transportation System is an ultra deepwater pipeline system that will support a number of prospects in the Gulf of Mexico, including the Holstein, Mad Dog, Atlantis and Thunder Horse field developments. To support the design of the deepest portions of the Mardi Gras Transportation System, a full-scale collapse test program was performed, and was aimed at measuring, quantifying and documenting the increase in pipe strength and collapse resistance as a result of the...

Abstract

With the increasing development of oil and gas reserves in water depths greater than 1500 m, linepipe used for deepwater and ultra-deepwater applications will require enhanced resistance to hydrostatic collapse. To support this need, Corus Tubes has been investigating methods by which increases in UOE linepipe collapse strength can be achieved. In particular, it has been theorised that modifications to the UOE manufacturing process can provide the necessary collapse strength...

Abstract

This paper contains the results of an experimental and analytical research program to determine the compressive buckling resistance of large-diameter, spiral-welded linepipe. Buckling resistance is important for pipe intended for service in Arctic, oil and gas pipeline systems, where pipes may be subjected to high bending strains caused by various ground movement events. The experimental work consisted of four full-scale tests of 30-inch (762 mm) diameter pipe subjected to various...

Abstract

Line pipe is often coated prior to installation in order to achieve some protection against the environment. Many of the coatings used today require the pipe to not only be cleaned and degreased, but also to be preheated to a temperature of 200–240°C during application of the coating material. A typical coating thermal cycle involves rapid heating of the pipe using induction coils, application of the coating, and quenching to cool the pipe for handling purposes. It is generally...

Abstract

Medgaz is a consortium of leading international energy companies, with the aim of designing, building and operating an Algerian-European gas pipeline via Spain. The offshore section of this pipeline will be 210 km long, traversing the Mediterranean Sea floor at a maximum depth of 2160 metres. The 24-inch diameter, grade X70 line will provide up to 8 billion cubic metres of natural gas per year, with first gas flow expected in 2009. To support the technical issues surrounding such an...

This paper is part of the World Heavy Oil Congress proceedings found on proceedings.com.

Abstract

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...

Abstract

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...

Abstract

Since the discovery of reserves in arctic regions, operators have been faced with a number of challenges, including assessing appropriate methods of transporting produced hydrocarbons to market. For pipeline systems, designers are required to deal with a number of unique environmental conditions not normally present in other regions of the world. These include ice scour, permafrost thaw and/or frost heave, leak detection and containment, and installation techniques. For offshore...