This paper analyzed the characteristics of volcanic reservoir space and its formation process in the case of intermediate-basic volcanic rock in the Carboniferous Jinlong Block

by integrating the core

thin section

logging

seismic and analytical data.The results show that:(1)feldspar and other minerals in the upper volcanic cycle altered to zeolite and chlorite and formed an unstable layer during the volcano eruption quiescent intervals;(2)tectonic movement at the Late Carboniferous developed fault-fracture and unconformity

and then meteoric freshwater could cause vertical and transverse dissolution along the fault-fracture and the unstable layer at the top of the cycle;(3)new fault-fracture formed through the tectonic activity of the La te Jurassic period

and the pore-fracture reservoir was compartmentalized and the accumulation space was basically finalized.Under the control of fault-fracture

palaeo-geomorphology and contact surfaces of the volcanic cycles

the reservoirs are characterized by zonation in the vertical direction and by lenticular geometry with greater thickness in the paleo high and losser thickness down the paleo-slope.As a whole

the reservoir is a complex"multi-zone overlapping"reservoir

composed of fractures

dissolved pores

and dissolved fractures.The geological model of pore-fracture volcanic reservoir is of great value for volcanic reservoir prediction and oil/gas exploration.