In well and reservoir management, optimum and accurate determination of multiple phase well-bore fluid entry is required to make decisions on water/gas shutoff opportunities. This can only be possible if good quality production log data is acquired and most importantly if accurate data analysis is done. This paper examines the drawbacks experienced using the conventional production log analysis methods and its associated risks. It will introduce an alternative probabilistic approach leading to more accurate results. The results of a case study will also be presented where a cement water shutoff was planned and executed based on the result of conventional analysis. It will also show how the results of the probabilistic approach would have saved the cost of the cement water shutoff