In this paper, we present an efficient strategic/tactical planning model for offshore oilfield development problem that is fairly generic and can be extended to include other complexities.The proposed multiperiod non-convex MINLP model for multi-field site includes three components (oil, water and gas) explicitly in the formulation using 3 rd and higher order polynomials avoiding bilinear and other nonlinear terms. With the objective of maximizing total NPV for long-term planning horizon, the model involves decisions related to FPSO (floating production, storage and offloading) installation and expansion schedule and respective oil, liquid and gas capacities, connection between the fields and FPSOs, well drilling schedule and production rates of these three components in each time period. The resulting model can be solved effectively with DICOPT for realistic instances and gives good quality solutions.