Abstract: As basic data for gas logging,log data are necessary in each stage of oilfield.Combined with well-log data,qualitative analysis of log data is a common method for logging interpretation,which is used for oil-gas-water identification.At present,how to carry out quantitative analysis and conduct uncertain layer evaluation of gas logging data should be focused on.In this paper,based on the characteristics of total hydrocarbon gas logging curve and oil-bearing properties of corresponding reservoirs,in combination with Triangualr daigram method and total hydrocarbon gas logging values,good application effects have been realized on uncertain layers indentification such as low resistivity oil layers.The method is of great application prospect for logging interpretation of development wells with less logging data.