Comprehensive Evaluation of Abnormal Resistivity and Reservoir Properties in Sandstone Reservoirs

The SP field, located in a geologically complex area, poses unique challenges in reservoir characterization due to abnormal resistivity phenomena. These anomalies, classified as Abnormal High Resistivity (AHR) and Abnormal Low Resistivity (ALR), complicate well log interpretation and hydrocarbon evaluation. AHR zones frequently yield resistivity values consistent with hydrocarbon-bearing reservoirs, even in water-saturated intervals, leading to misinterpretation. Conversely, ALR zones exhibit low resistivity despite favorable porosity and hydrocarbon indicators, further obscuring reservoir assessment. The primary objective of this study is to identify the geological and petrophysical factors contributing to these anomalies and to refine well log interpretation models to improve accuracy. Data from 13 wells were analyzed, integrating core samples, well logs, and advanced petrophysical techniques to address these challenges systematically, the research successfully overcomes interpretation challenges posed by AHR and ALR. The proposed workflows not only enhance accuracy in characterizing reservoir properties but also offer a practical methodology for reducing uncertainties in hydrocarbon zone detection.