LAUSR

Abstract Universal existence of the filled vug or cave in carbonate reservoir complicates the fluid flow as the coexistence of free flow and porous flow. The fills in vug increase the flow resistance and affect the water invasion for a natural bottom-water reservoir. This influence was explored through experimental tests on a conceptual discrete fractured-vuggy model. This model was abstracted from Tahe Oilfield in China, in the form of isolated vugs connected by fractures network. A new scaling method was proposed for this discrete media according to the similarity of the displacement front of water drive. It was found that vug filling displays a negative role during the natural bottom-water drive. This impact depends on the geological feature of fractured-vuggy reservoir. A stronger sensitivity occurred to the fracture well-developed stratum that the vug filling made the pre-existing or new preferential corridors more significant. As a result, the systems with multiple flow paths became more “heterogeneous”. In this condition, a lower water intensity and oil viscosity can ease these adverse effects.