Scheduling dynamically positioned tankers for offshore oil offloading

Abstract

The operation of offshore oil fields entails transferring oil that accumulates in Floating Production Storage and Offloading Units to onshore terminals. To this end, a fleet of dynamically positioned tankers is deployed for transferring oil from large oil fields, which should be scheduled to meet operational constraints while minimising costs and economic losses. This work presents a mixed-integer linear programming (MILP) formulation for the problem of scheduling shuttle tankers that accounts for the essential constraints. Combined with an MILP solver, the model serves as a decision support tool to guide engineers in daily operations. A family of valid inequalities is proposed to strengthen the MILP formulation and reduce solving time with state-of-the-art solvers. Computational results are also reported on the application of the proposed model in tandem with a rolling horizon strategy.

Keywords:

• offshore oil operations
• shuttle tankers
• mixed-integer linear programming
• valid inequalities
• rolling horizon strategy

Acknowledgement

The authors thank Eng. Fernando Pereira from the BG Group for bringing to our attention the shuttle tanker scheduling problem.