WELL-LOGGING IDENTIFICATION METHOD OF VOLCANIC GAS RESERVOIR IN WUCAIWAN AREA,JUNGGAR BASIN

Volcanic rocks in Wucaiwan area,Junggar Basin,belong to the low-porosity and low-permeability reservoir with tight lithology and high resistivity.And the lithologic contribution to resistivity is larger than that of fluid.Therefore,there exist great difficulties in identifying gas layer.Through theoretical understanding,the author proposes that the volcanic gas reservoir can be identified using three-porosity difference value and ratio,superimposition of apparent marker,and cross-analysis of both acoustic travel time and resistivity.