A Discrete-time MILP Formulation for the Optimal Scheduling of Maintenance Tasks on Oil and Gas Wells and Surface Facilities

Onshore oil and gas exploitation areas are usually composed of a numerous set of wells geographically distributed. The extraction of oil and gas requires complex and expensive equipment, including production devices and surface facilities. To keep efficiency sufficiently high, wells need regular maintenance. In this work, we address the scheduling of maintenance tasks on oil and gas wells and surface facilities. The main challenge is to determine the assignment and sequencing of operations combined with vehicle routing decisions, also accounting for preemption and precedence constraints. The goal is to maximize the use of available resources and also minimize both the production loss and the risk of failure in every well, using a mixed integer linear programming (MILP) formulation. We solve three case studies with increasing complexity to finally assess the model performance in real-size problems of the Argentine oil and gas industry.