Multi-probe low-frequency induction log and high-frequency induction log if the reservoir contains the low resistivity annulus zone

A low resistivity annulus appearing near the well due to reservoir fluid displacement by mud filtrate is a reliable indicator of movable oil presence in the reservoir. In practical cases estimation of low resistivity annulus parameters is possible based on high-frequency induction logging data analysis. When interpreting practical data of other resistivity logging methods its influence on signals is usually not taken into account. The paper discusses the results of the 5IK and VIKIZ logs numerical simulation which substantiate the possibility of identifying low resistivity annulus according to multi-probe low-frequency induction logging in geoelectric conditions typical for the Cretaceous mixed-saturation reservoirs of the Imilorskoye oilfield.