Séminaire conjoint CIRRELT-Chaire de recherche du Canada en distributique-Chaire de recherche du Canada en logistique et en transport

TITRE : A Branch-and-Price-and-Cut Algorithm for the Workover Rig Routing Problem

CONFÉRENCIÈRE : Glaydston Ribeiro, Department of Engineering, Federal University of Espirito Santo, Brazil

DATE et ENDROIT : 14 mars, 10h30, salle 5441, Pavillon André-Aisenstadt, Campus de l’Université de Montréal

RESPONSABLE : Jean-François Cordeau (514-343-7307)

RÉSUMÉ : The workover rig routing problem (WRRP) is a variant of the vehicle routing problem with time windows (VRPTW) and arises in the operations of onshore oil fields. In this problem, a set of workover rigs located at different positions must service oil wells requesting maintenance as soon as possible. When a well requires maintenance, its production is reduced or stopped for safety reasons and a workover rig must service it. It is therefore important to service the wells in a timely fashion in order to minimize the production loss. In our case, the decision of which workover rig should be sent to perform some maintenance service is based on production, current location of the workover rig in relation to the wells, type of service to be performed, and a planning horizon. Whereas for classical VRPTWs the objective is to minimize route length in the WRRP the objective is to minimize the total lost production We propose a mathematical formulation for the WRRP based on a traditional formulation for the VRPTW and a branch-and-price-and-cut algorithm for solving it. Computational experiments show that this approach can solve large-scale instances whose dimensions are close to the ones of real-life problems. This is a joint work with Guy Desaulniers, Jacques Desrosiers and Gilbert Laporte.