Wave Propagation at Marginal Ice Zone

Abstract

Abstract Moving in Artic and Sub-Artic regions imposes significant challenges on engineering aspects of offshore Oil & Gas fields development. These new developments have to be subjected to environment composed of level ice sheets, ice ridges, marginal ice zones and free sea. Marginal ice zone means the transition between the free sea (no ice) and ice. It is accepted that waves damp out in heavy pack ice, but the relationship between the amount of wave damping with ice concentration and distance into the ice field is not fully understood, area requiring further research and development. This paper presents the main results of the program "wave propagation in marginal ice zone" initiated through a French JIP in 2009. It identifies the state of practices and state of art on wave propagation at marginal ice zone. A comparison is presented between ice floe modelling technique, experimental results and theoretical values. Finally the wave tank experiments carried out in the BGO First basin are presented in detail for this program. Introduction The continuous interest of Total E&P and the engineering companies (Saipem, Technip, Doris, Entrepose) for the Artic and Sub-Artic regions has lead them to begin a R&D study on the topic "wave propagation at marginal ice zone" through a French JIP (ref 1). The objective of this JIP is to analyse wave propagation at marginal ice zone by means of model tests in BGO FIRST. Firstly, this paper presents an overview of the knowledge on the marginal ice zone and the wave propagation. This preparatory work has lead to a reflection on the way to perform model tests to study the phenomena. In addition, a number of challenges are developed in relation to the definition of the model tests, the physical model of ice floes, the selection of the parameters to be tested, their range, and the reliability of the experimentation performed in a limited space basin. This paper will present the model tests setup and the test procedure, including the ice floe modelling and instrumentation. At the end, the results of the experimentation are presented and compared with some analytical calculations.