Although pipelines can be built under the sea, that process is economically and technically demanding, so the majority of oil at sea is transported by tanker ships. The market size for oil and gas pipeline tremendous experienced construction growth prior to the economic downturn in 2008. The industry grew from $23 billion in 2006 to $39 billion in 2008 After faltering in 2009. demand for pipeline expansion and updating increase d the following year as energy production grew By 2012, almost 32.000 miles of North American pipeline were being planned or under constmuction. Several major North American pipeline under development in 2012 included