Nigerian National Petroleum Corporation (NNPC) goes with the flow of oil and gas. NNPC oversees the petroleum industry of one of the world's top, albeit politically turbulent, oil-producing countries. NNPC produces oil through controlling partnerships with major world oil companies. The company has four refineries, in Port Harcourt (2), Warri, and Haduna) with a nominal total capacity of 445,000 barrels per day (although disrepair and lack of investment have severely curtailed functional capacity). NNPC also oversees the nation's natural gas industry and liquefied natural gas operations. It oversees 5,000 kilometers of oil and gas pipeline, 20-plus storage tanks and about 10 liquefied petroleum gas depots.