Preparing For Large Scale Ocean Bottom Seismic Surveys In Norway
B.A. King, N. Moyle, E. Sadikhov, G.W. Simensen and T. Nilsen
Event name: Marine Acquisition Workshop 2018
Session: Advances in Marine Seismic Acquisition: The Receiver Side
Publication date: 22 August 2018
Info: Extended abstract, PDF ( 1.09Mb )
Price: € 20
Ocean bottom seismic (OBS) surveys have been acquired on the Norwegian continental shelf since the 1990s, almost exclusively for the aim of field development or reservoir monitoring. Due to high acquisition cost, OBS surveys were traditionally small compared to towed streamer surveys, although they have yielded superior reservoir images especially beneath overburden anomalies, beneath gas clouds or in the presence of complex faulting. As OBS becomes cheaper, the prospect of acquiring high quality OBS surveys for exploration on a large scale is a realistic goal. Further efficiencies are sought through designing sparse receiver arrays, counter balanced by dense source carpets. This study examines the relationship between receiver sampling and data quality, in a typical North Sea setting. By decimating dense recorded data and performing modelling studies, we demonstrate that receiver sampling can be greatly reduced without compromising image quality at expected reservoir depths. We examine the inevitable compromise to image quality in the overburden and discuss possible mitigating actions.