Identification of Favorable Basement Reservoirs Based on Comparison of Well Logging and Mud Logging Spider Diagrams

Basement reservoirs are characterized by complex storage spaces and reservoir heterogeneity, making it difficult to effectively identify oil and gas-bearing reservoirs using conventional well logging or mud logging data. To achieve a detailed evaluation of basement reservoirs, a multi-index comprehensive evaluation method is applied, based on core analysis and well testing data. This method combines conventional well logging, imaging logging, and mud logging data to conduct a study of reservoir logging facies. In order to visually display the reservoir characteristics of different lithologies and physical properties, a spider diagram is used to represent the logging facies. Through repeated experiments, nine representative logging curve values, including RD, ZDEN, GR, RMSL, C2/C1, δ-CALX, CNC, DT, and TG, are selected for the basement reservoir in the study area. These values are standardized and transformed using the Log function to create a spider diagram, providing an overall assessment of the basement reservoir. The analysis results show that this spider diagram is effective in identifying different types of basement reservoirs, enhancing the accuracy of favorable basement reservoir identification.