Bohai L oilfield has undergone multiple adjustments since it was exploited, such as well pattern internal infilling, changing well patterns, and reversing lines. The scattered distribution of remaining oil on the flat and extremely complicated vertical flooding law resulted in difficulty for tapping the remaining oil. Based on the data of core, well logging, seismic, production dynamic and other results, the thick reservoir can be comprehensively characterized, so as to guide the remaining oil fine characterization and potential development. The results show that the plane contact styles of single sand body is mainly in butt type, and the vertical overlap mainly in cut type. The remaining oil of the southern vertical accretion type leaf body is mainly concentrated near the vicinity of the fault, the buried hill area and the sand?body deposition margin, which can be tapped using directional wells. The remaining oil of the central prophase frond is mainly concentrated in the top of the thick sand body and the lower part of the thin interbe, which can be tapped using horizontal wells.