With the deepening of exploration and development in the Middle East Block, many oil wells have found the existence of light oil one after another. In view of the problems of low density, high gas-oil ratio and difficult identification of light oil, by analyzing the corresponding logging response characteristics, finding logging cyres sensitive to oil quality, a volatilization index reflecting the volatility of fluids was calculated; at the same time, the triangular chart of gas logging is digitized, and the calculation method of hydrocarbon ratio is optimized in combination with the composition of actual gas logging components, calculating triangular plate indices that can reflect more characteristics of different hydrocarbon components. Combining triangle plate index with volatilization index, a comprehensive logging recognition chart which can simultaneously characterize the volatility of light oil and the characteristics of hydrocarbon components is established. This chart has good recognition effect for light oil, and has a good guiding significance for later exploration and development and reservoir evaluation in this area.