Making New with Old: Reprocessing Vintage Seismic Data from the Western Arctic Islands using Modern Methods

In 1997 the Geological Survey of Canada (GSC) signed a Memory Of Understanding (MOU) with Panarctic Oils, the Arctic Islands Exploration Group and the Offshore Arctic Exploration Group joint ventures parties allowing GSC researchers a privileged access to 38 000 km of various quality 2-D seismic data collected in the Western Arctic Islands. The dataset contains many artifacts related to the uniqueness of this ice-covered acquisition environment such as coherent noise and local changes in frequency content both respectively attributed to the presence of permafrost and to variations of its physical properties as well as transition areas (i.e. land to sea-ice). Other artifacts include acquisition footprints that hamper shallow subsurface interpretation, seafloor multiples which plague entire sections and hyperbolic reflections caused by steeply dipping geometries that preclude imaging deeper geological units properly. Each of these processing challenges is tackled individually using modern pre-stack and post-stack methods. Qualitative and quantitative quality control (QC) of the reprocessing show that artifacts are greatly attenuated as both the signal-to-noise (S/N) ratio and the coherency of the reflections have been significantly improved.