Pipeline

A pipeline is a complex system of pipes used for the long-distance transportation of liquids or gases.

These networks typically move materials to market areas where they can be consumed by people or industries. Pipelines are vital for modern life because they can move almost any chemically stable substance. This includes crude and refined petroleum, biofuels, and natural gas. They also transport water for drinking or irrigation, sewage, and even steam. Some specialized systems, known as pneumatic systems, use suction pressure to move solid objects.

Because they are often more efficient than roads or rail, they are essential infrastructure for global energy.

The mechanism of a pipeline depends on the material being moved.

For oil, pipelines are often made of steel or plastic tubes and are usually buried underground. To keep the oil moving, pump stations are placed at intervals along the line. Natural gas pipelines are typically constructed of carbon steel. To make transport easier, natural gas is often pressurized into liquids called natural gas liquids, or NGLs. For example, propane converts from a gas to a liquid under light pressure of about 100 psi.

Once in liquid form, these substances can be moved more efficiently through the system.

Maintaining these systems requires specialized tools and protective methods.

Because corrosion and leakage are the main causes of pollution, pipes must be protected. Engineers use wood lagging, concrete coating, or high-density polyethylene to prevent damage. They may also use sacrificial cathodes to fight rust. To clean the interior, workers use devices called "pigs," also known as scrapers or "Go-devils." These devices are launched from a station and travel through the pipe to remove wax or debris. Some are "smart pigs," which are intelligent devices used to detect anomalies like dents, cracks, or metal loss caused by corrosion.

History shows how these systems have evolved to meet global needs.

The first crude oil pipeline was built in the 1860s by the Oil Transport Association. This wrought iron line ran from an oil field in Pennsylvania to a railroad station in Oil Creek. During World War II, submarine pipelines were developed for military use. In 1944, during Operation Pluto, pipelines were built across the English Channel. These underwater lines provided an estimated 8 percent of all petroleum products used by the Allies on the Western Front. This history demonstrates how pipelines have moved from simple iron tubes to massive undersea networks.

The scale of the global pipeline network is enormous.

By 2025, the global trunk or transmission pipeline network is expected to be approximately 2.19 million km long. North America accounts for about 44 percent of this total. Within this network, the United States holds 65 percent, Russia holds 8 percent, and Canada holds 3 percent. These three countries combined contain 76 percent of all pipelines. Pipelines are also much more economical than other transport methods. In 2014, transporting crude oil by pipeline cost about $5 per barrel. In contrast, rail transport cost between $10 and $15 per barrel, making pipelines the preferred choice for high volumes.

Different types of substances require unique pipeline setups.

While oil and gas are common, pipelines can also move coal or ore through a process called slurry transport. In a slurry pipeline, the solid material is mixed with water before being sent through the pipe. One example is the Savage River Slurry pipeline in Tasmania, Australia, built in 1967. Other pipelines carry ammonia, such as the 2,500 km Transammiak line that once connected Russia to Ukraine. Even hydrogen is transported through specialized pipes. However, some substances like ethanol are harder to move. Ethanol is corrosive and absorbs water, so it requires dedicated pipelines to avoid contaminating existing ones.

Pipelines are deeply connected to global economics and geopolitics.

In the United States, 70 percent of crude oil and petroleum products are shipped by pipeline. In Canada, 97 percent of natural gas and petroleum products use pipelines. Because they are so efficient, they are often targets during military conflicts. Changes in energy sources can also shift how pipelines are used. For instance, new US-supplied natural gas can displace gas formerly shipped from western Canada to Ontario. As more North American pipelines are built, exports of products like propane and butane increase across all three US coasts. This connectivity helps stabilize markets and provides energy to distant regions.