A correction method based on geometric factor for resistivity log response of thinly laminated sand reservoirs: A case study

The log response of thin oil layers is greatly subject to environmental factors such as shoulder beds, resulting in errors high enough to influence the appraisal of rock lithology and fluid properties and increasing the difficulty of interpretation of logging curves and the effective evaluation of thinly laminated sand. The development of high-resolution logging instruments and logging curve processing technology improves the resolution and accuracy of logs, but with some limitations. So far, the geometric factor theory has been an effective approximate approach for induction logging correction. Based on the working principle of the induction/resistivity log and on previous studies, we have developed a new model to correct the resistivity log response of thin layers by taking advantage of the geometric factor. This method can improve the accuracy of the resistivity log for the calculation of porosity and water saturation. Our case study indicates that more reliable resistivity can be acquired to better characterize thin layers.