A Mixed Integer-Programming Model For Periodic Routing Of Special Vessels In Offshore Oil Industry

In order to maintain the production of offshore oil wells, the National Iranian Oil Company periodically services facilities and equipment located in oil wellheads with mobile wellhead servants. It also gives technical supports to oil wellheads and mobile wellhead servants with supporter vessels. Due to supply limitations, there are not enough special vessels (namely supporter vessels and mobile wellhead servants) compared to the number of oil wellheads. The failure of special vessels to service oil wellheads and supporter vessels to technically support mobile wellhead servants based on a predetermined plan, will lead to considerable loss in production performance of oil wells and hence higher costs. We propose a mixed integer programming model and a heuristic algorithm to find the best plan to service oil wellheads considering travel and shortage costs. Computational results in both simulated and real life instances are reported and performance of the proposed algorithm is evaluated.