ICEOP project

Background

The large Barents Sea comprises both Norwegian and Russian territorial areas. Oil and gas exploration activites on both Norwegian and Russian continental shelf have been undertaken during the last decades. Potential large estimates for undiscovered and discovered oil and gas reserves have beeen established. One good example is the large Shtokman gas field.

The Arctic Barents Sea and, in particular, the north and north-east part of the Barents Sea have challenging ice conditions with level ice, ice rubble, ice ridges, icebergs and ice drift. Ice conditions change during the year. The climate is extreme, with low temperatures, snow and ice and strong winds. During the summer period, there is 24 hour daylight and this changes to complete darkness during winter (December-January). Water depth in the Barents Sea is around 200-300 meters.

The Norwegian Continental shelf represented by Barents Sea north-east is one of the areas with high estimates for undiscovered petroleum reserves with figures in the range of 1,370 millions Sm3 o.e. (expected) with high and low estimates on 2,460 and 350 millions Sm3 o.e., which is comparable to estimates for the Norwegian Continental shelf of the North Sea and Norwegian Sea. Similary, the Russian part of the Barents Sea (south of Frans Josef Land and west of Novaja Semlja) have large petreoleum resources.

Design of offshore structures in Arctic waters is strongly depended on accurate and representative estimates of local and global ice loads. These loadings are, in general, contact forces transmitted to the structures during interaction with level ice, ice ridges or icebergs. The structures can have contact surfaces that are vertical or have sloping sides in the water line. The prediction of ice forces on structures relies an a thorough understanding of ice mechanics as well as on in-depth knowledge of interaction between ice features and structures. The complexities of the constitutive behavior of ice and the variations in ice failure modes are major obstacles in the development of efficient and reliable methods for the estimation of ice loads on bottom mounted fixed or compliant structures. Current activities in the Arctic Region are putting even stronger demands on the oil and gas industry in exploration as well as other realted industrial processes. The High North is clearly an area of primary interest for Russia, Norway, as well as the international community. Based on the current oil price level, all companies involved in the oil and gas industry see the need for cost reduction, and more cost-effective and innovative solutions for all parts of the oil and gas exploration and production system. Therefore, the oil and gas industry is giving attention to the improvement of methods for prediction of ice loads that are exerted on structures by first year level ice, multi-year level ice and ridges as well as icebergs.

Another scenarion with ice actions on offshore structures is when ridged ice hits a structure. Ice ridges are established either due to compression or shear in the ice cover and consists of a consolidated layer together with parts which are partly consolidated or not consolidated. Loads on structures due to the actions of ridged ice are complex and little information exists on full-scale loads from ice ridges. Actions from ice ridges are assumed to establish dimension load on a structure and offshore installations in ice-infested areas, when icebergs are not present. In the past decades, greate effort has been put into predicting ice ridge loads. A study by Timco and Croasdale shows that ice ridge loads on a vertical structure predicted by twenty-one ice experts ranged with a factor of five. The study shows that research on ice ridge structure interactions is still needed. In many cases, ice ridges govern the design of offshore petroleum exploration and production structures. Various ice ridge characteristics are important for offshore engineering problems, including overall dimension of deformed ice feature and its strength and degree of consolidation.

Main objective

The ICEOP project main objective is to give increasedbusiness development opportunities for oil andgas exploration and production in the arctic by improvedmaritime accessibility, better knowledge of ice conditions andmore accurate models to ensure safeand environmental friendly field developments.

The project shall:

Work packages in the project

WP1 – Barents Sea Ice Conditions

WP2 – Field Expeditions and Surveys

In order to get more physical data tocalibrate and to use for interpretation of WP1 information the project willexecute field expeditions. The field data will be analyzed in cold climatelaboratories (WP3). Mobile laboratory Units will also be used on theexpeditions.

WP3 – Laboratory Analysis of Field Data

WP4 – Ice Mechanic Models & Marine Operations

The work in this work-package will utilize results from WP1 and followingly be adjusted/based on ice conditions (ice, ice ridges and ice bergs) and statistics. One will then develop models for ice and ice-structure interaction, to contribute to more accurate and safe models and methods with the purpose to reduce risks, in order to facilitate and support oil and gas developments and marine transport activities primarily in the Barents Sea North and East.

Safe operations will also ensure apositive environmental effect, reduced risk for oil-spill, safe operations,implies reduced risk for incidents and accidents.

It will also contribute to safer maritime transports (ship to ship, industry) by investigation and building a database of Polar Code compliant risk estimates for the Barents Sea area.

One will derive the average spatial and temporal distribution of ice conditions posing unacceptable risk to operations according to the POLARIS RIO definitions, based on regional coupled sea ice/ocean model.