Abstract: The vuggy reservoir is one of the most important reservoir types showed by the cores and well logging data in Tahe Subsalt Area. The confused reservoir genetic mechanisms of vuggy reservoir lead to its complex distribution which restricts the production and development in this area. Three kinds of environment are established by lots of cores observation, and the traces superimposed on petrography and geochemistry make it the markers for discriminating them. A-vug developed in the context of continental sea which leads to less terrigenous deposition in Caledonian. It is characterized by eogenetic petrography and higher δ13C and δ18O value. B-vug developed in the context of subaerial exposure which leads to mess terrigenous deposition in early Hercynian. It is characterized by serious oxidation and karst and depleted δ13C and δ18O value. C-vug which developed in late Hercynian is distinguished by the hydrothermal mineral observation. The mixture of multiple fluid makes it difficult to discriminate this type of vug by δ13C and δ18O value. The distribution of different vuggy reservoirs is established by the serious genetic mechanisms study. The distribution of A-vug reservoir is controlled by the three-order sequence stratigraphic boundary vertically and bank facies in plane at the top of the Yijianfang and Lianglitage Formations. B-vug reservoir is controlled by cave distribution nearby the salt pinchout and large-scale fault in main Subsalt Area respectively, where there is an obscure line between them. C-vug reservoir is controlled by the deep fault.

Key words: Tahe Oilfield, subsalt area, vuggy reservoir, reservoir feature, genetic analysis