Re: These refineries are not being permanently shut down.
Economics 50: A functional monopoly artificially restricting supply is a tactic designed to increase profits. In the oil industry the most common way to do that is to shut down refineries for maintenance, as obsolete, as unfit for the current market, etc. Pick and choose. It is difficult to tell what the reality is.
A strike by workers may have the same effect as any other reason for shutting down a refinery, and may be encouraged by management for that reason. However, the purpose of a strike is to encourage management to share the obscene profits of the oil industry with the people who make them possible, the people with their boots on the ground and gloves around the tools.