Shale Volume Estimation By Using Image Logs (FMI and EMI) In One Of The Iranian Oil Reservoir

Shale volume is one of the most important parameters studied in all petrophysical studies and reservoir quality in terms of importance in reservoir production. One of the methods to measure the petrophysical properties is coring. Using the core to measure petrophysical properties is associated with limitations and problems. For example, cores are associated with high costs and are usually not fully recycled, especially in a carbonate reservoir in Iran. Image logs are often used for fracture analysis but in other fields such as shale volume estimation, porosity calculation, sediment environment identification, etc. have not been used much.In this paper, the shale volume is estimated by applying the binarization method on the FMI image log in one of the carbonate reservoirs in south-western Iran. To verify the proposed method, the shale volume is calculated by the gamma ray log index (IGR). Finally, the shale volume values obtained from the FMI and gamma ray log were compared. The shale volumes obtained from the two logs show a good match except for the points that refer to places where open fractures are in the vicinity of the shale layers. To reduce the error at these points, we use GR log next to FMI and use EMI (electrical borehole imaging) instead of FMI.

Keywords:

FMI , EMI , Shale volume , Binarization , Gamma ray log , Fracture