Petroleum pipelines transport crude oil or natural gas liquids, and there are three main types of petroleum pipelines involved in this process: gathering systems, crude oil pipeline systems, and refined products pipelines systems. The gathering pipeline systems gather the crude oil or natural gas liquid from the production wells. It is then transported with the crude oil pipeline system to a refinery. Once the petroleum is refined into products such as gasoline or kerosene, it is transported via the refined products pipeline systems to storage or distribution stations.