Efficiency of Ice Management for Arctic Offshore Operations

Abstract

The exploration and production of polar oil and gas fields, which are technologically challenging due to extreme weather conditions, are also constrained by strong environmental issues. Safe and economical activities in such hostile and fragile regions require very insightful engineering. The presence of sea ice is representing a triple challenge: economical, technological and environmental. This makes the Arctic exploration and production activities complex. Ice Management (IM) is one of the tools that could efficiently assist to develop Arctic reserves. However, for each project that uses IM operations, a preliminary study is required to evaluate the efficiency of these support operations and to estimate the possible extension in the season of operation of a field. Efficiency of an IM philosophy can be estimated in a global view based on the extension in the operability window. In a more detailed view, it can be assessed taking into account the optimal number of icebreakers, the IM patterns, the available time for eventual disconnection, and the floe size reduction (leading to ice load reduction). For this study, we will focus on the ice floe size and loads reduction. The most common approach for physical management of sea ice is the one where icebreakers reduce floe size of the drifting ice upstream the floating platform (ref. Moran et al. [1], Coche et al. [2]). This paper describes this philosophy and demonstrates based on real-time simulation that its benefit is limited to mild ice scenarios such as unidirectional ice drift. A more efficient way to manage sea ice is (1) to identify the most hazardous events (e.g. big ridges); (2) prioritize these events; and (3) deal with them starting by the most hazardous one.

Extreme Value Estimation of Mooring Loads Based on Station-Keeping Trials in Ice

“…Copyright © ASME V007T07A018-9 The major factors influencing the IM operations are the level ice thickness, ice draft, ice drift speed and capacity of the icebreaker [8]. Regarding the ice conditions, the ice thickness/draft and ice drift speed can be considered for calculation of the average unit ice momentum in order to estimate the efficiency of the IM operations as demonstrated in figure 22.…”

“…Ice management generally involves various operational procedures so as to reduce the ice action on various types of offshore structures [8,9]. For the present full-scale experiment, various types of ice management schemes are applied in relation to the station keeping trials for various ice conditions.…”

Extreme Value Estimation of Mooring Loads Based on Station-Keeping Trials in Ice

“…Copyright © 2020 ASME V007T07A018-9 The major factors influencing the IM operations are the level ice thickness, ice draft, ice drift speed and capacity of the icebreaker [8]. Regarding the ice conditions, the ice thickness/draft and ice drift speed can be considered for calculation of the average unit ice momentum in order to estimate the efficiency of the IM operations as demonstrated in figure 22.…”

An Artificial Bee Colony optimization-based approach for sizing and composition of Arctic offshore drilling support fleets considering cost-efficiency

“…If there is a possibility that the limit will be exceeded, the installation must be evacuated and relocated from the drilling point in advance with the help of tugs and icebreakers, resulting in high financial losses. It is possible to extend the range of safe operating conditions by increasing the number of icebreakers to assist in the ice management around the installation (El Bakkay et al 2014). However, the cost of ice management resources is also high.…”