Calculation Method of Oil Saturation of Mixed Shale Based on Lithology Classification
The mixed shale oil sweet spot of Permian Lucaogou formation in Jimsar sag, Junggar basin has many lithology types, complex mineral composition and strong heterogeneity, and the accuracy of oil saturation calculated with conventional logging by Archie formula is low. On the basis of core, thin section and logging data in the study area, more than 20 lithologies are classified into 9 lithologies according to lithology principal components by core calibration logging, cluster analysis, data mining and distribution intersection, and the sensitive parameters of conventional logging are excavated to establish the lithology identification standard of conventional logging of mixed shale oil. Based on the seven relationships of shale oil desserts and the main controlling factors of saturation of Archie formula, the dominant lithology of 5 types of shale oil desserts is defined, and the porosity model and petroelectric parameters are determined by lithology. The oil saturation calculation model for different lithologies of mixed shale oil is established by using closed coring analysis and inverse calculation of formation water resistivity combined with rock electrical parameters. Applied to the calculation of effective thickness oil saturation of mixed shale oil, the average error between calculated oil saturation and core analysis oil saturation is 2.06％, which is higher than 5.00％ of the reserve standard. Which provides a new idea and method for calculating high-precision oil saturation in conventional logging of mixed shale oil.
shale oillithology identificationoil saturationpetrophysics experimentJimsar sag
万方数据
维普
