Use of the ISO 19906 Arctic Structures Standard

Abstract

The new ISO 19906 Arctic Offshore Structures standard contains provisions relating to a number of different types of offshore oil and gas structures in the Arctic and in other cold regions. Its provisions supplement those of ISO 19902 (steel offshore structures), ISO 19903 (concrete offshore structures), ISO 19904–1 (floating offshore structures) and other standards in the ISO 19900 series. This paper focuses on important arctic provisions and on how the standard can be used in conjunction with the other ISO offshore structures standards. Issues dealt with include features of arctic and cold regions; when the standard should be used; types of ice actions and how they should be applied; ice actions in the context of other physical environmental actions; manmade islands; subsea installations; ice data collection; monitoring; interpretation and analysis; ice management systems and operational aspects of arctic structures; and low temperature materials and equipment. Introduction Background Many of the structure design concepts used in arctic regions are similar to those in other areas and the same design principles apply. Nevertheless, the arctic environment poses a number of additional challenges due to marine icing on exposed surfaces, actions from sea ice and icebergs, structural vibrations as a result of ice actions, ice rubble encroachment, and brash ice build-up from icebreaker operations. In many cases, special operational procedures are required in harsh environmental conditions, which need to be factored into the designs. As a brittle solid, ice can exert considerable pressure over small contact areas, frequently exceeding average values over the loaded area. Local design requirements for ice are an integral part of the design process. It is because of the above issues that the ISO 19906 standard [1] was developed and, because their implementation can differ from standard practice, is why the present paper reviews its application. Terminology The ISO series has some particularities in terms of terminology with respect to North American usage. The main one is the use of the term "action" instead of "load", which is a more general term that could imply a load, an acceleration or a displacement. The characteristic value of an action or parameter is one that has a specified annual probability of being exceeded, which is often interpreted as a return period value. The representative value of an action is a characteristic value or some other value that is used for design.

Protecting Offshore Pipelines Against Drifting Ice: A Discussion on Standards and Guidelines

“…This is the standard's first edition, and an adoption without modification of the document produced by the International Standards Organisation known as ISO 19906. The standard provides recommendations and guidance for the design, construction, transportation, installation and removal of offshore structures related to the activities of the petroleum and natural gas industries in the Arctic and other cold regions (see also [23]). It deals with ice actions for in-field components referenced in ISO 13628, including flowlines, umbilicals, manifolds, wellheads, subsea storage tanks and processing equipment.…”