Use and abuse of seismic data in reservoir characterisation

All seismic data contain a mixture of signal and noise. In detailed reservo ir characterisation, it is commonly difficult to distinguish between real f eatures and seismic artefacts. This is especially a problem when interpreti ng seismic attribute maps. Such maps are widely used tools during reservoir description, but serious pitfalls exist, which may lead to erroneous inter pretations and fatal development plans for oil fields. A recent interpretat ion of seismic attribute maps from a seismic survey collected across Gullve ig, an oil field located in the northern North Sea, has been used to illust rate how small faults can be recognised and mapped from such maps. We appli ed available well data (including core data) and two seismic surveys from t he same area, and present convincing evidence that the vast majority of lin ear features seen on the seismic attribute maps are, in fact, seismic artef acts and not faults. The data from Gullveig are furthermore supplemented by observations from the nearby Gullfaks Field and discussions on the topic o f seismic noise. We use these observations and discussions to stress the im portance of using all available data to guide and quality control the struc tural interpretation of attribute map features before utilising such interp retations as input to reservoir modelling or well planning. (C) 2001 Elsevi er Science Ltd. All rights reserved.