Research on Optimization Methods for Logging Physical Property Parameter Interpretation Models in LMD Oilfield

The currently used physical property parameter model was established in 2010 using multiple regression methods. After years of application, it has shown inadequacies. To meet the requirements of fine reservoir characterization, the existing model has been optimized to improve interpretation accuracy. To enhance the classification accuracy of sample points, the study refined the partitioning of sample points for the physical property parameter model by categorizing them according to oil layer type, effective thickness, and Flow Zone Index (FZI), progressing from macro to micro levels. Curve fitting was then performed separately for sample points within each partition to derive formulas with higher correlation, thereby completing the optimization of the physical property parameter model. After classifying sample points by oil layer type and effective thickness, the correlation coefficients between physical property parameters and logging curves were higher compared to classification solely by oil layer group, demonstrating the rationality of macro-level sample point subdivision. Evaluation results of physical property parameters revealed that within each reservoir type, porosity and permeability decreased as the FZI index declined, with lithological changes consistent with core analysis results. This indicates that the FZI index can accurately reflect the microscopic pore structure characteristics of reservoirs. The optimized parameter model achieved a porosity calculation error within 4%, and permeability calculation errors were within 100 mD for Class I oil layers, 80 mD for Class II oil layers, and 50 mD for Class III oil layers. This study redefined partitioning rules based on the distribution characteristics of sample points on charts, improving the interpretation accuracy of physical property parameters. The findings provide guidance for potential exploitation of various oil layers, development plan formulation, and tracking adjustments in oilfields.