What is it about?
The Pipe-Laying Support Vessel (PLSV) is one of the most critical agents in offshore oil and gas operations in ultra-deep waters. These vessels are responsible for connecting pipelines between sub-sea oil wells and production platforms, thus allowing production to flow. The problem is similar to other scheduling problems in different industrial environments with tasks assigned and sequenced on available resources. However, more complex aspects are considered, such as the fleet's heterogeneity with different capacities, various pipeline sizes, multiple tasks executed in each well, different pipeline arrival dates at the port, and others. We developed mathematical optimization models to properly define the problem, using commercial solvers to produce solutions to it, providing a decision support tool for PLSV planners.
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Why is it important?
The most important aspect is the methodology's capacity to provide feasible and quality solutions for the problem in a reasonable computational time. In general, solutions developed without a decision support tool present violations related to the problem's restrictions, with capacity violations, non-compliance with pipeline arrival dates, and others. Computational experiments detail the advantages of different mathematical formulations for different problem sizes.
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This page is a summary of: Scheduling pipe laying support vessels with non-anticipatory family setup times and intersections between sets of operations, International Journal of Production Research, November 2020, Taylor & Francis, DOI: 10.1080/00207543.2020.1828637.
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Instances for the PLSV Scheduling Problem: An Identical Parallel Machine Approach with Non-Anticipatory Family Setup Times
Set of PLSV instances generated based on the real data about the pipe laying support vessel (PLSV) scheduling problem. We model the problem as an identical parallel machine scheduling problem with non-anticipatory family setup times. The problem consists of scheduling a set of operations on a set of machines, representing the vessels, respecting capacity, and eligibility constraints. The operations are the connections to be executed on sub-sea oil wells, allowing the production to flow to surface platforms. The wells are represented by jobs, and to be completed, all operations associated with it must be finished. The processing time of operations is fixed and not machine-dependent. One operation may be associated with several jobs simultaneously, creating intersections between operations subsets. The objective is to minimize the total weighted completion time of jobs, where the weight of a job represents its production level. Thus, the objective aims to anticipate the completion of wells with higher production levels. The material contains 72 instances with different problem characteristics and a number of operations and machines.
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