Modeling and Lagrangian relaxation based heuristic for scheduling oil wells in oilfield production

The oil well scheduling is to determine the turn on/off time and oil flow rates of wells in a given oil reservoir subject to the oil demand, well bore pressure requirements with minimizing the total production operating cost and start-up cost. In comparison with ordinary well scheduling problems in the literature, the problem has the following special features: well grouping, well minimum-up and minimum-down time limitation. The problem is formulated as the mixed integer nonlinear programming model by considering above-mentioned the objective and practical constraints. The NP-hardness of the problem motivates us to develop the Lagrangian relaxation based heuristic to solve the problem approximately. The computational experiment on the randomly generated instances is carried out. The numerical results illustrate that the Lagrangian heuristic algorithm can obtain high-quality schedules in a relatively short time, compared with the commercial solver CPLEX.