Reservoir Analysis and Fluid Effect Identification in Y-Field, Niger Delta Basin through Amplitude Versus Offset (AVO) Study

Amplitude versus offset (AVO) analysis has been a useful technique for reservoir study and has played a vital role in reservoir fluid characterisation. This approach makes use of the variation of amplitude of seismic data with offset or angle and this has been applied to the study of reservoirs in Y-field for the purpose of maximum production. Zoeppritz equation was used to produce synthetics for AVO modeling while two-terms Aki-Richard equations were used to generate various AVO volumes ranging from Intercept (A), gradient (B) and Scaled Poisson’s Ratio Change (aA+bB) volumes. The results revealed good correlation between real seismic and Zoeppritz synthetics, an indication of good AVO modeling and a reliable AVO cubes. The reservoirs were classified as type II and Scaled Poisson’s Ratio Change clearly identified units with hydrocarbon accumulation discriminating it from the effect of lithology. Therefore, the study concluded that AVO analysis can provide critical parameters in fluid identification and discrimination.