In the oil and gas industry, flowlines are pipe lines that connect a single wellhead to a manifold or process equipment. In a larger well field, multiple flowlines may connect individual wells to a manifold. Then a gathering line may transfer the flow from the manifold to a pre-process stage or to a transportation facility or vessel. Flowlines may be in a land or subsea well field and may be buried or at grade on the surface of land or seafloor. Gathering lines are similar to flowlines but collect the flow from multiple flowlines.

Flowlines are located at the well site tied to a specific well. It may be a metallic pipe or a hose. Most flowlines are very short in length but others may be run for kilometers in onshore applications. In comparison gather lines are used after flowlines have brought the fluid to a manifold or other piece of process equipment, these lines may run for miles or up to a process ship if off shore. Flowlines are constructed onshore and may be lowered to the seafloor, and have terminal connectors that make installation at the well head easier.