APPLICATION OF SEISMIC-LOG JOINT INVERSION TO PREDICTION OF MESOZOIC SANDSTONE RESERVOIR IN NORTH DEPRESSION OF SOUTH YELLOW SEA BASIN

In the exploration areas with complicated tectonic background and few drilling wells, effective seismic wave impedance inversion processing and reservoir prediction are the keys to offshore oil and gas resource assessment. For the seriously heterogeneous and complex lithologic association of the Cretaceous sandstone reservoirs in the South Yellow Sea Basin, wave impedance inversion processing is performed for 2D multi-trace seismic data, using the methods of seismic-log sparse impulse joint constrained inversion and low-frequency model building technique under the constraints of structural framework. The wave impedance inversion section may depict spatial distribution pattern of the reservoir, show physical changes inside the reservoir and predict the distribution pattern of the prospective reservoir. The reservoir prediction suggests that the Cretaceous Taizhou Formation has a multi-layer mudstone as hydrocarbon source rocks with low wave impedance, and there are two layers of sandstone reservoirs with high wave impedance. Compared with drilling data, it is proved that the sandstone reservoir is valuable.