Abstract: This paper proposes a study of structures,lithology,fracture,physical parameters and reservoir criteria for the carbOTiifcrous formations in the District No. 6 and No. 7,Karamay oilfields by using logging data,based on which —△NR and △t—△NR cross—plots are established for identifying tuff,andesite,andesite—volcanic breccia,altered volcanic breccia—andesite and sand—conglomerate. The close relationship between hydrocarbon distribution and unconformity depth in these districts can be obtained throgh porosity plots and thickness map of the payzone from digital processing data results of 26 wells associated with the structural map and initial production map. The results of secondary interpretation indicate that the reservoir thickness of all wells is 1783. 9m.among which 1230m oil pay unpcnctrated by perforation are found to be production potential.

Key words: Karamay, Carboniferous, logging information, lithological cross plot