This paper proposes a new research method for braided river sedimentation on the beach shore based on the action of tidal currents. This study conducts a statistical analysis of the length and width of a single braided river and channel bar sand body, and establishes the relationship function model of the quantitative scale of a single braided river and the channel bar. According to the core and logging data of the Nanwu area of the target oilfield, a quantitative methodology based on the calculation of a single accretion scale is established from three perspectives: the architecture interface identification of the accretion, the occurrence and scale calculation of the interlayer, and the scale calculation of the single accretion. In the Nanwu area, the inclination angle of the accretion interface in the direction of the long axis is 0.78–1.32°, and the inclination angle of the accretion interface in the direction of the short axis is 2.02–3.78°. The density of a single well group is generally 2–3 per well. The length of the single accretion in the channel bar is 700–1500 m. Based on these findings, this paper completes the construction of the architecture of the channel bar, and establishes the quantitative scale calculation method for architecture elements for different levels of braided river reservoirs. The research results provide support for the prediction of the braided river reservoir architecture and the remaining oil in similar blocks.

The geological estimated hydrocarbon reserves of the Mesozoic granite buried-hill reservoir in the PL oilfield exceed 200 million tons. During the exploration stage, it was commonly considered that the PL buried-hill reservoir should demonstrate a “layered” edge water reservoir mode, because of weathering and tectonics. However, during a later stage, the formation of water was found at structurally high locations, which does not fit the intuition. Therefore, a suitable model is still lacking. Based on the comprehensive information of thin-section, core plug, well logging, and seismic data, etc., the buried-hill of the PL oilfield was re-divided into three northeast–southwest-trending zones. In this model, the reservoir is layered, with each layer having the characteristics of bottom water and two kinds of horizontal and vertical seepage. This new model fits the field-drilling test very well. These insights can effectively guide the exploration and development practice for this kind of buried-hill.