Reservoir-Control Effect of Faults in Pingbei Area of Xihu Depression

Faults in the northern part of Pinghu tectonic zone (Pingbei area) are complex, complicated faults not only control the formation of traps, but also play a crucial role in oil and gas migration and preservation. Based on the latest seismic and drilling data, this study reviewed the fault characteristics and the function of controlling trap and reservoir in the northern Pingbei area. The results showed that the northern Pinghu area was controlled by the early nasal uplifting and faults were very well developed, forming a broom fault system spreading from WS to NE. Structural traps such as fault anticline, fault nose and fault block are mainly developed. At the same time, the NE-trending faults combined with the banded delta and the tidal sand from the western sources formed a series of fault-lithology composite traps. The faults controlling effect on oil and gas accumulation is mainly manifested in two aspects: on one hand, as source faults, they can divert hydrocarbons; on the other hand, as trap boundaries, they play a key role in sealing oil and gas. This study can provide some technical support for the next exploration deployment in Pingbei area.