A GTL facility for a fixed offshore hydrocarbon production platform which comprises a deck attached to a base that is secured to the sea floor. The GTL facility comprises a syngas reactor for converting natural gas into syngas and a liquids production unit for converting the syngas into a hydrocarbon liquid. Furthermore, at least one of the syngas reactor and the liquids production unit comprises a catalyst which is constructed using PI micro-reactor technology. As a result, the GTL unit is sufficiently small to be located on the deck of the platform.