Multicomponent modeling of a conglomerate bar deposit

Brad D. Nazar

A multicomponent seismic survey was obtained over the Carrot Creek oilfield of West Central Alberta. The data shows a significant Cardium amplitude anomalies on the radial component corresponding to producing conglomerate bodies. To obtain an understanding of the origin of these anomalies multicomponent modeling was undertaken. By generating and processing P-P (vertical component) and P-Sv (radial component) shot records both a P-P and P-Sv synthetic section were produced. The preliminary results obtained were quite encouraging in that amplitude anomalies corresponding to the location of the conglomerate bar were successfully modeled. Much more modeling must however be undertaken in order to determine the cause of the anomalies.

In addition the results showed the importance of using depth variant mapping, instead of an asymptotic technique, to sort converted-wave data. It was also shown that an improved P-Sv moveout correction for converted-waves is necessary. The velocities derived from the Dix equation for converted-waves overcorrects the data at far offsets.

The modeling results also indicated that AVO effects may be present on both the vertical and radial components of the surface seismic data.