Abstract: Based on the characteristics of fractured-vuggy carbonate reservoirs in Tahe Oilfield as well as dynamic and static
data from pilot production，visualized models of different combination of fractured and vuggy were built up through similar
theory and forward modeling in this study. Comparison and verification of the reservoir space type of corresponding water cut
law were done by physical simulation experiment. The result reveals the physical nature of water cut performance，and provides
the experimental and theoretical basis for the efficient development of reservoir. The experiment simulation proves that there
are five basic types of water cut performance in fractured-vuggy carbonate reservoirs. Each type is related to the specific
reservoir geological characteristics，combination relations of vuggy and fracture，water energy and connection between aquifer
and deposit. Compared to sandstone reservoirs，carbonate reservoirs have more complicated characteristics in water influx.
The influx always happened in fractures and in the cave inside，and the oil-water interface levels up in horizontal position. The
coupling of conduit flow and permeation is the direction of research in the future.

Key words: water cut performance, fractured-vuggy reservoirs, physical simulation, reservoir space, flow mechanism