A refinery is a somewhat ramshackle and antiquated terran structure, designed to speed up the arduous process of the vespene gas mining on the more desolate terran worlds within the Koprulu sector. Constructed on top of a geyser, the refinery processes the raw gas into a harvestable form and then automatically packages the gas into containers easily transportable by SCVs.
Refineries have a core that, if damaged, can destroy the entire refinery in an explosion.
SCVs retrieve 8 gas per trip; three SCVs are required for optimal harvesting, assuming that the command center is placed as close as possible to the refinery. SCVs may still retrieve gas from a depleted geyser, but the yield will be greatly reduced (to 2 per trip).
In StarCraft II: Wings of Liberty, refineries can be upgraded to automated refineries once the player acquires fifteen protoss research points. Automated refineries cost twice as many minerals and build slower, taking forty-five seconds, but are otherwise identical to the normal refinery in terms of stats.
All structures repair themselves to 50% life. All structure fires are automatically put out.
This all-in-one safety system automatically dispatches robotic drones to put out any fires and perform basic repairs on damaged structures. Although these drones are effective at doing basic repairs, they do not have a strong enough AI to perform the more delicate repairs needed to restore a structure past half life.
We have adapted protosswarp technology to transport gas canisters straight from the refinery to the command center, eliminating the need for SCVs to carry them back. Why the protoss have never thought to transport vespene in this fashion is a mystery. Perhaps they lack terran creativity and pragmatism, or possibly their primitive superstitions forbid the practice.
In Co-op MissionsNova can use automated refineries to harvest vespene without workers once she reaches Level 7. Swann can use vespene harvesters to gather gas at a faster rate from his and his ally's vespene geysers.
Alexei Stukov creates infested refineries. They are biological, regenerate 0.2734 health per second and do not burn when damaged, but are otherwise identical to refineries.
Visual development of the refinery for StarCraft II didn't change much over the course of development. The piston and canister collecting arms were difficult to implement, and artwork was redone once, but the design itself remained the same.
The upgrade of the automated refinery was part of the final wave of terran buildings needing cosmetic improvements for the tech purchase feature in the single player campaign of Wings of Liberty. Like the terran mercenary units, the idea was to change about 60% of the model to make it unique, but not so unique that it wouldn't be recognized as a refinery.