Small and Full Scale Testing of Flexible Pipes in Cold Environment for Arctic Use
Authors: Gabet C. , Chicheportiche S. , Vivet R. , Taravel-Condat C. 
Published: December 2011

Flexible pipes have been used to transport oil and gas in offshore applications for more than 30 years. As the Arctic regions begin to emerge as significant oil and gas provinces and exploration continues to expand, it is timely to assess the technical requirements of this environment and gain an understanding of technology capability to meet these requirements. Potential oil and gas development opportunities in the Arctic present a number of specific challenges [1–3] ranging from the need to use ice class installation vessels, constructions specificities, concerns about logistics, people and environment, and challenges for both installation and operation steps.

This paper presents a review of the technical challenges of the Arctic environment, dealing with the suitability of flexible pipes materials in cold environment. Its aim is to describe some of the small and full scale tests performed in Flexi France, Technip's main flexible pipe R&D center and manufacturing facility, to extend the use of such pipes in Arctic conditions.

Considering the potential brittle behaviour of some materials at low temperatures, mechanical tests have been performed at a laboratory scale down to -60°C. Results on polymers and carbon steels (wires and forgings), obtained via several tests such as impact, tensile and fatigue tests, defects propagation and others, are presented. An actual background on full scale tests implemented in the past or to be implemented in the future is also made.

Introduction

With a significant increase in energy demand forecast over the long term, it is inevitable that the Arctic Region, with respectively 13% and 30% of world's undiscovered reserves in Oil and Natural Gas, will be further developed at some stage in the future. Technip, a large energy contracting company, is geared-up and ready to execute the increasingly challenging infrastructure projects that are required to enable oil and gas production from the Arctic Region to be performed in an economic, safe and environmentally responsible manner.

Historically, the Oil and Gas Industry has developed by expanding its existing technologies into new environments. Logically, the further development of the Arctic Region will be another step-out of established experience from existing sub-Arctic and Arctic projects. Indeed, since 1960's, Technip has been successfully involved in a number of sub-Arctic projects like Hibernia, Sakhalin, Terra Nova, White Rose and Shtokman. Hence, the further development of the Arctic is likely to follow a process of evolution rather than revolution.

This paper will deal with flexible pipes as a means to acheminate Oil and Gas Subsea in the Arctic Region. After a short description of the flexible pipe structure, and some words about the challenges associated with extracting Oil and Gas in Arctic Region, it will present part of the results that have been obtained on flexible pipes materials. The aim is clearly to demonstrate the suitability of such materials to be used in such a harsh and environmentally sensitive region.