Abstract:
Reservoir fluids in Pearl River Mouth Basin include condensate gas, volatile oil, and conventional light oil, exhibiting extremely complex fluid properties. Due to the similar characteristics of different fluids on logging curves, it is challenging to identify them only using logging curves. As fundamental data for exploration and development, gas logging data have significant application value in reservoir fluid component identification. This study screened six gas logging-derived parameters that are sensitive to critical fluids such as condensate gas and volatile oil. Based on these parameters, a gas-logging polar plot was constructed to obtain the areas of light and heavy components. Calculating the area ratio of light-to-heavy components effectively amplifies the differences in fluid properties. By establishing the correlation between the gas-oil ratio (GOR) of production-tested intervals and the light-heavy component area ratio, this method enables rapid and accurate GOR calculation only using gas logging data in the field, thereby determining reservoir fluid properties and reducing costs associated with traditional sampling operations. This approach has been widely applied in Pearl River Mouth Basin. Practical verification shows that the accuracy of quantitative fluid property discrimination using GOR calculated by this method reaches 90%, significantly improving the reliability of reservoir fluid identification in the study area and providing an effective basis for subsequent exploration and development decisions.