Abstract: The P oilfield structure is located in the northeastern end of the Tanlu fault zone’s eastern branch and the middle section of the Bohai South uplift zone. The structure as a whole has a nearly north-south trend and develops a series of “flower-like” normal faults in the recent strata from north to south. In the plane,it presents a “ridge-trench” alternating structural feature. Through research on the fault properties,regional tectonic evolution,and structural stress action mechanism,this paper believes that the “flower-like” normal faults in the area are not the accompanying faults of regional strike-slip faults,but are formed by the plastic deformation of the basement mudstone under the action of regional thermal subsidence differences. Based on the genesis of “flower-like” normal faults,targeted data processing and fault system identification technologies were proposed：multi-information-driven gas cloud area imaging enhancement and frequency domain multi-scale fault detection technology. Through fine fault description,the paper guides the detailed interpretation of the 16 block structure and the optimal deployment of wells,providing guidance for the optimization of well positions and the efficient development of the oilfield.

Key words: “ridge-trench” alternating structural feature, thermal deposition, tectonic reactivity, “flower-like” normal faults, fault detection