A multiperiod mixed-integer linear programming (MILP) model formulation is presented for the planning and scheduling of investment and operation in offshore oil field facilities. The formulation employs a general objective function that optimizes a selected economic indicator (e.g., net present value). For a given planning horizon, the decision variables in the model are the choice of reservoirs to develop, selection from among candidate well sites, the well drilling and platform installation schedule, capacities of well and production platforms, and the fluid production rates from wells for each time period. The formulation incorporates the nonlinear reservoir performance, surface pressure constraints, and drilling rig resource constraints. The resulting MILP model contains several thousand binary variables and is intractable using a full space branch and bound technique. A sequential decomposition strategy using aggregation of time periods and wells, followed by successive disaggregation, is proposed. Two examples are presented to illustrate the performance of the algorithm.