Abstract: The fine characterization of the interbed in the reservoir can provide an important basis for exploring the distribution pattern of the residual oil and adjusting the development plan of the oil field. In this study, the interbed in the shallow-water braided delta in the PL Oilfield is re-classified from the perspective of the difference in the characterization method used for the interbed. A layer-by-layer quantitative characterization of the interbed is performed based on the principle of layered modeling. The study suggests that the interbed in the shallow-water braided delta in PL Oilfield can be divided into four types including the spacer interlayer, inter-sand interlayer, sand interlayer, and physical interlayer. These interlayers correspond to the level 6 to level 3 configuration interfaces in the reservoir architecture. Three different modeling methods are used to quantitatively characterize the four different interbeds layer by layer. Specifically, the spacer interlayer and sand interlayer are characterized by a borehole data-based deterministic three-dimensional sand drawing technology, the inter-sand interlayer is characterized using a self-adaptive river-based method with the single sand body controlling during the process, and the physical interlayer is characterized by an equivalent characterization method. The layered quantitative characterization method of the interbed is a simple and practical approach that reflects the reservoir structure and the interbed distribution characteristics in the shallowwater braided delta well.

Key words: shallow-water braided delta, interbed, layered characterization, quantitative characterization, equivalent characterization