While it may seem peculiar for there to be oil deposits on a space station, the international conglomerate Goodwinn Corporation of earth saw it fit to ship a large amount of remaining fossil fuel directly to Calydon for use in conventional machines that still were pervasively operated. They installed huge reservoirs of oil on the Underside of the station, and recover it by pumping it to the surface of Calydon.
They have since been abandoned, and the pumps are mostly inoperable. They are still connected by gravtrain rail to Sebastopol.
What little is functional is typically held in contest by either the Humanists or the Chestonites, although sometimes by the Reapers or Radchildren.