Interpreting multicomponent seismic data: Clastic and carbonate case histories
Robert R. Stewart
Analysing both the compressional (PP) and converted (PS) wavefields from a multicomponent seismic survey can provide more information about subsurface structures, lithologies and their fluid saturants. This paper discusses the techniques of jointly interpreting P-wave data in association with converted-wave seismic data. The methods include log analysis, generation of synthetic seismograms, VSP correlation, along with registering, picking, and calculating ratios of the PP and PS sections. Two cases of oilfields in clastic (sand-shale) environments are discussed - the Cambay Basin, India and the Williston Basin (Ross Lake), Saskatchewan. In addition, two carbonate cases are considered from the Cantarell oilfield in Mexico and the Lousana field, Alberta. Vp/Vs values from traveltime thickness (isochron) ratios are especially useful for characterizing lithologies.