Using Wigner-Ville Distribution Properties for Thin Bed Identification
Event name: 79th EAGE Conference and Exhibition 2017
Session: Seismic Interpretation - Spectral Methods
Publication date: 12 June 2017
Info: Extended abstract, PDF ( 1.9Mb )
Price: € 20
In the search for ever more subtle reservoirs we often deal with hydrocarbon deposits, where the thickness of individual layers is below the seismic tuning thickness. Several methods were developed in the time and frequency domain to circumvent or go below this fundamental limitation of the seismic method. In this paper we investigate properties of the Wigner-Ville (WVD) time-frequency distribution, and especially of the cross-terms. We start with the mathematical definition of the WVD and investigate cross-term properties for two Gaussian time signals. We then examine the WVD of a wedge model and find that the cross-term shows variations even if the wedge thickness is below the tuning limit. We concentrate on the time location of the first-order minimum of the WVD cross-term which indicates the centre of the wedge even below the tuning thickness. Subsequently we apply this property for thin layer identification in a real seismic example. We conclude that tracking the location of the first-order minimum of the WVD cross-term can indicate the existence of layers below the tuning thickness in seismic data, and locate the mid-point between the top and base of the tuned layer.