Fractured-vuggy carbonate reservoirs have various types of reservoir space with significantly different sizes including vugs

fractures

and caverns. Fluid flow in this type of reservoirs is complicated by the coexistence of flow through the dissolved pores

flow in the fractures and flow in the caverns. The common numerical simulators are no longer suitable for fluid flow in this complex medium. In order to study the development mechanics and the remaining oil distribution in the reservoir

a mathematical model that couples cavern flow and fracture flow with seepage flow is established and discretized with the finite volume method. The equations are solved by using the self-adaptation method. A numerical simulation software for the fractured-vuggy reservoir is developed. The flows within a well group and a fractured-vuggy unit in Tahe oilfield were simulated respectively. The results show that the remaining oil in this kind of reservoirs mainly include the remaining oil at the top of caverns

marginal remaining oil

attic oil

the remaining oil at the bottom of caverns

the remaining oil around high permeable channel and the remaining oil in filled caverns. The results are consistent with the actual production data

verifying effectiveness of the fractured-vuggy carbonate reservoir numerical simulation model. This model is useful for extracting remaining oil and enhanced oil recovery for fractured-vuggy carbonate reservoirs.