An offshore hydrocarbon production system in which gases are economically stored for transport. After the produced hydrocarbons are separated into liquid (crude oil) and gases, the gases are separated into heavy and light gases. The heavy gases, which consist primarily of propane and butane (and possibly pentane and hexane), are stored as LPG (liquid petroleum gas) in a refrigerated LPG tank. The light gases (methane and other light gases) are hydrated and the ice crystals are stored in a refrigerated hydrate tank.