A submarine pipeline (also known as marine, subsea or offshore pipeline) is a pipeline that is laid on the seabed or below it inside a trench.[1][2] In some cases, the pipeline is mostly on-land but in places it crosses water expanses, such as small seas, straits and rivers.[3] Submarine pipelines are used primarily to carry oil or gas, but transportation of water is also important.[3] A distinction is sometimes made between a flowline and a pipeline.[1][3][4] The former is an intrafield pipeline, in the sense that it is used to connect subsea wellheads, manifolds and the platform within a particular development field. The latter, sometimes referred to as an export pipeline, is used to bring the resource to shore.[1] Sizeable pipeline construction projects need to take into account many factors, such as the offshore ecology, geohazards and environmental loading – they are often undertaken by multidisciplinary, international teams.[1]
