There are vast resources of both gas and oil in the Canadian Beaufort Sea; however, due to its harsh environment, this region presents unique challenges for evacuation and rescue. An installation in this environment will be subjected to several different ice regimes throughout the year and each must be considered in the design of the escape, evacuation, and rescue (EER) systems. The new ISO Arctic Offshore Structures standard (ISO, 2010) instructs that the level of safety at an offshore structure shall be the same year-round. For evacuation in particular, the standard also recommends having preferred (usually a helicopter), primary, and secondary evacuation strategies in place (Poplin et al, 2011). Approaches to evacuation can include direct (dry), indirect (semi-dry), or wet methods. Additionally, previous studies have shown that a single system for evacuation is not sufficient for the Canadian Arctic environment (see e.g. Wright et al., 2003a, 2003b).
Timco and Dickins (2005) have summarized the range of ice environments that can be encountered in the Beaufort Sea and discussed their implications with respect to evacuation. For example, when pack ice is present, the ice sheets can be quite mobile. Moving ice fails against the structure and clears around it. Launching of lifeboats would have to be done at a suitable distance to ensure that they do not get caught in the ice failing against the structure, as this active ice area represents regions of damaged ice where lifeboat launching is unsafe. The minimum distance and direction the lifeboat must be launched away from the structure to avoid breaking ice is an example of one strategy consideration as discussed by Poplin and Timco (2003) for conical structures and Timco et al (2006) for vertical-sided structures.
The present paper does not provide a detailed examination of the number of systems that presently exist for potential use in ice-covered waters. These types of studies have been completed elsewhere (see, for example, Wright et al. (2003a, 2003b), Poplin et al. (1998), Poplin (2010) or Poplin et al. (2011)). Rather, it builds upon work such as Timco and Dickins (2005), and focuses instead on evaluating ice conditions typical to the Beaufort Sea and how these conditions impose limitations on generic evacuation systems. Helicopter use is not examined here.
The emphasis of the results are for the nearshore water depths (<50m); however, many of the results considering evacuation in pack ice conditions are applicable to the deeper regions of the Beaufort. The output from this project consists of evacuation strategies for each season and essential information for putting these strategies into practice for operators and regulators. Knowledge of these issues and strategies for dealing with them are of paramount importance to both offshore operators and regulators before production activity takes place in the Canadian Arctic offshore environment.
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