The major interest of this study is focused on Electrical submersible pumps optimization in oil field suffering from increasing in water cut ,decreasing in reservoir pressure and as a result reduction in oil production for the purpose of creating a higher drawdown on the formation and achieving comparatively more production. The study covers 6 wells equipped with ESPs in one of Libyan oil field located in South Western part of Sirte basin. Nodal analysis approach was applied between the reservoir and the wellhead ignoring the surface facilities in order to carry out the essential production optimization. PROSPER software was used to perform the necessary calculations. Production has been simulated in PROSPER through two different cases scenario comparing with the actual current case: 1. Analysis and Re-optimizing of the present pump at the same producing flow rate in the intention of getting reduction in number of stages and higher pump efficiency comparing to the current pump. 2. Design a new pump with more production rate taking into account the capability of the well and trying to achieve optimum pump setting depth. Additionally, sensitivity analysis was carried out based on the effect of rising water cut percentage over well life time on the ability of a reservoir to deliver fluids to the surface. In order to evaluate the mentioned different scenarios, economical analysis was done to estimate future cash flows and to have an assessment of profit or loss. The main profit indicators were used are: Net Present Value (Cumulative Discounted Net Cash Flow) and PayOut time. The results showed that applying second case senario will increase the profit up to 52 % comparing to the current and first case senario.