AVO analysis of carbonates

J. Helen Isaac, Donald C. Lawton

We analyze amplitude variations with offset (AVO) in 2D seismic data from the Redwater area of Alberta to investigate whether it is possible to differentiate between limestone and dolomite in the Middle Leduc Formation. We used the P-wave sonic and density logs from two wells, one with dolomite in the Middle Leduc and the other with limestone. Shear wave sonic logs had to be estimated from the P-wave logs. The correlations between the synthetic offset gathers and the seismic data at the projected location of the wells is poor. We are not able to pick a consistent event on the offset gathers for the limestone well. Modification of the dolomite well logs to replace the dolomite with limestone is unsatisfactory because of the lack of shear wave log data for proper modelling.