摘要
Updip pinch-out reservoir is one of the lithologic reservoirs.Identifying updip pinch-out reservoir is a major task of lithological reservoir exploration.In this study,analysis of the 3D seismic reflection,instantaneous phase and acoustic impedance is conducted to identify and interpret the sandstone.It is found that the combined data of acoustic impedance and the instantaneous phase has better detectability and is more reliable indicator of the sandstone distribution than any of these individual seismic data including the 3D seismic reflection,instantaneous phase and acoustic impedance.In Wanchang area,combined analysis of the acoustic impedance and instantaneous phase in the subaqueous slump fans is a valid approach for identifying and interpreting the updip pinch-out sandstone.Two major findings are as follows:(1)Combined analysis of the cores,seismic attribution and the distribution of the synsedimentary faults could exactly identify the distribution of the subaqueous slump fans in the Wanchang area.(2)After identifying updip pinch-out sandstone in subaqueous slump fans using acoustic impedance and the instantaneous phase in the Wanchang area,there are at least two stages updip pinch-out sandstone near well WC1 in subaqueous slump fans which are most potential in Wanchang area.