Gathering Pipelines: The beginning of delivering today’s energy supply
New discoveries of domestic oil and natural gas are helping to supply the country’s increasing demand for energy resources. The recent discoveries could be the largest in U.S. history and will require new infrastructure, especially gathering pipelines, that collect the material from the production areas for delivery to consumers.
Four primary areas of the country are currently being explored for major deposits of natural gas or oil. These areas include the Barnett, Haynesville and Marcellus Shales, which are producing natural gas, and the Bakken Shale formation, which is producing oil. Each of the shale formations is located in a different area of the country, ranging from Texas and Louisiana, to New York and Pennsylvania, to the northern regions of Montana and North Dakota.
Gathering pipelines are crucial in that they serve as the starting point of the national energy infrastructure. Gathering lines hook up to the well and collect the liquid or gas stream when it is first brought to the surface. The stream is then measured to determine how much liquid or gas has been produced. Gathering lines then collect the oil and natural gas and transport the product to treatment, processing or refining facilities.
When oil or natural gas is produced, the stream of hydrocarbons is often a mix of liquids and gaseous material. A separator is used to remove produced liquids form the gaseous material. Natural gas processing is required to extract natural gas liquids from the natural gas stream. Refining is the process used to treat oil. Impurities like water, non-hydrocarbon materials and other contaminants, like sand, also have to be removed. This ensures the oil and natural gas meets certain quality specifications. The products are then moved downstream to end-use consumers and delivery points via a transmission pipeline.
Gathering lines are different from transmission or local distribution pipelines in a number of ways. Not all gathering lines are buried. Some lie on top of the ground, running between the wellhead and other production facilities. Gathering pipelines can be made of steel, plastic and, occasionally, fiberglass. Steel gathering pipelines are the strongest, but need to be protected from corrosion. Plastic gathering lines must be buried to protect them from sun exposure and other potentially hazardous situations, like fires.
Gathering pipelines are shorter in length, ranging form just a few feet to several miles and they tend to be smaller in diameter and operate at lower pressures than transmission pipelines. The Pipeline and Hazardous Materials Safety Administration is responsible for implementing rules governing the operations of gathering lines. In many cases, however, a state agency enforces the federal rules. For more information on gathering lines in your state, contact the state regulatory agency responsible for pipelines.