Acoustic impedance interpretation for hydrocarbon extent, offshore Brunei Darussalam

This study performed seismic inverse modelling and interpretation of the acoustic impedance volume to decipher the vertical and lateral limits of gas saturation in two sands in a field currently under development. The two sands, seperated by about 350 m, were chosen for their contrasting characters (Table 1): a shallower Sand 1 strongly defined on seismic data, having higher average thickness, porosity and gas saturation at well locations; and a poorer quality Sand 2 with lower average gas saturation, not as clearly defined on seismic data, occurring at about the start of overpressured depths. Hence this research aimed to study the effectiveness and limitations of seismic inverse modelling and acoustic impedance interpretation on two reservoir sands having markedly differing characteristics.