During the lifecycle of an oilfield project, well development is a critical phase due to intensive investments required for capital cost. Determining whether it is economical to develop an oilfield or not and finding the best plan for field development are the main concerns in this field of study. Drainage area development and production planning are crucial in a steam assisted gravity drainage (SAGD) project of the oil sand industry. In this study, an optimization framework for planning the development of SAGD drainage areas under uncertainty is presented. The proposed framework includes the following two major elements. First, a mixed integer optimization model is developed to arrange the multiperiod development plan of the drainage areas with consideration of capital and steam allocation restrictions. Second, uncertainties in crude oil price and reservoir production are investigated based on a multistage stochastic programming model. The results demonstrate that the method can effectively generate an economically optimal development plan that maximizes the profit.