Abstract: It′s very difficult for multi-media well test model to describe the geologic characteristics accurately in fractured-vuggy reservoir due to the high heterogeneity and network-like reservoir space.The big size vugs which are taken as zero-dimensional entities are the main fluid accumulating space，and the strap-shaped formations which are taken as one-dimensional entities are the connection channels，composing the discrete media network(DMN).According to fluid flow in the network，the two-phase mathematical model for the numerical well test of fractured-vuggy reservoirs is established.The effects of flow channels′ permeability，big vugs′ capacity and distance from well are discussed.Result shows that the “hollow” feature shown in pressure derivative curves is caused by the cross flow of big size vugs to the percolation Network.Finally，a field data analysis shows that the interpretation results of discrete media network numerical well test model conform to the three-dimensional geological model.

Key words: fractured-vuggy reservoir, discrete media network, numerical well test, big size dissolved cavern, flow channel