One important process for revitalization and optimisation of mature reservoirs is secondary recovery by waterflood. However, some engineers do not understand the science and, consequently, without proper plan lose millions of dollars of investment because they target reservoirs for waterflood secondary process which do not possess appropriate characters. This paper presents screening criteria for waterflood projects in a matured field in the Niger Delta region of Nigeria. Data set for a field X in the Niger delata was simulated. Sensitivity analysis was carried using different scenario and their results were reported. Six parameters which can be used to screen reservoirs for water flood potential were proposed in this paper.The result of the evaluation showed that waterflood are best applicable for reservoirs with residual oil saturation of less that 33%,gas saturation of greater than 15% and API gravity of less than 30cP.