Source: BTS.Oil and Gas Pipelines Mileage in the United States,
Most of the American oil refineries are located nearby port
areas as coastal cities are large consumption markets. Since the 1960s domestic oil production was declining and
oil imports were increasing, which reinforced the locational
relevance of coastal refineries. As such, the length of domestic oil
pipelines did not change much, even as national consumption
increased. Since 2005, a strong growth in domestic shale gas
production placed pressures for the development of additional
gas pipelines. This expansion has led to a substantial increase
in the length of gas pipelines with the reconversion of existing
oil pipelines, adding additional pipelines along an existing
line and expanding the network to service new areas and markets.
Such developments match the ongoing
of global energy systems from liquid energy sources such as
petroleum to gas energy sources such as natural gas.