U.S. natural gas production has risen 33% since 2008, and crude oil production has jumped 87%. In between natural gas and crude oil is a group of hydrocarbons referred to as natural gas liquids (NGLs). NGLs are differentiated from one another by the number of carbon atoms in their molecular chain. Natural gas liquids are extracted as a mixture of hydrocarbons and other gases and are produced and separated from one of two sources: natural gas processing or crude oil refining. In 2008, U.S. production of NGLs was 653 million barrels, and in 2017 it was 1,381 million barrels, more than doubling in 10 years. Sources of Production

Most of the increase in NGL production has come from tight shale natural gas formations, some of which have high concentrations of NGLs. Although NGLs may be obtained from both natural gas processing and crude oil refining, they come predominantly from the former—with over 90% of all U.S. NGL production coming from natural gas processing. Natural gas, when extracted from a wellhead, contains methane, a variety of other hydrocarbons (most of them NGLs), and various impurities including hydrogen sulfide and water. Transportation Infrastructure

The rapid growth of NGL production has outpaced the development of supporting infrastructure. NGLs are expensive to transport and handle—requiring high pressures and low temperatures to keep them in a liquid state for shipment. A network of processing plants, fractionation sites, petrochemical olefin crackers, and distribution methods is necessary to move NGLs from production to their markets. Moreover, the surplus of NGLs brought about by domestic production growth is increasing the need for infrastructure to aid in exporting of NGLs and the storage of NGLs domestically. Economics

The United States is by far the largest producer of NGLs in the world. As of 2017, the United States accounted for over one-third of global NGL production. These lower prices make them a very competitive feedstock for petrochemical companies to make products like plastic. Furthermore, the rising value of NGLs is driving the focus of natural gas production away from the Gulf Coast to tighter shale formations in the Midwest and Northeast that have more NGLs. As the industry makes technological improvements in extraction, production costs have declined and NGL production has increased. In 2017, approximately 37% of U.S. NGL production was exported, with Canada, Japan, and China being the largest recipients, receiving 18%, 16%, and 11% of U.S. exports, respectively. imports of NGLs have fallen by over 30%. The resultant surge in demand led to a spike in propane prices for the year. Congressional Interest

Infrastructure, production, safety, the environment, and economics are all critical to the NGL market and are of interest to Congress. Other bills that have been introduced in the 115 th Congress address infrastructure, taxes, safety, and other energy topics, and are not specifically targeting NGLs. The rise in production of each NGL—ethane, propane, butane, isobutane, and pentanes—since 2008 has been large.
The U.S. oil and natural gas industries have gone through a "renaissance" of production. Technological improvements in hydraulic fracturing and horizontal drilling have unlocked enormous oil and natural gas resources from tight formations, such as shale. In conjunction with the rise in oil and natural gas production, U.S. production of natural gas liquids has also increased.
Natural gas liquids (NGLs) are a group of hydrocarbons that includes ethane, propane, butane, isobutane, and natural gasoline. NGLs are differentiated from one another by the number of carbon atoms in their molecular chain. They have a wide variety of applications from specialized fuels (e.g., propane, butane) to petrochemical feedstocks for making products like plastic and fertilizers.
NGLs are extracted as byproducts in the production of natural gas and oil. Of these two sources, natural gas processing is by far the most significant, contributing over 90% of NGL production in 2016. When extracted from a well, natural gas is mixed with other hydrocarbons—many of them NGLs—and various impurities. In order for the natural gas to be marketable, the NGLs and impurities must then be removed. The separated NGLs may then be discarded or undergo further processing in order to be sold. The relatively high value of NGLs combined with the rise in natural gas production has led to a rapid rise in NGL production as it has become more economical for processors to sell the separated NGLs.
The United States is by far the largest producer of NGLs in the world, accounting for more than a third of global production. Domestic NGL production has more than doubled in the 10 years since 2008, reaching 1,381 million barrels in 2017. Ethane and propane are the two most prevalent NGLs, and together they account for more than 70% of all domestic production. As NGL production has risen, it has increasingly outstripped domestic consumption, which has remained relatively flat since 2010 (when EIA began to collect data). Consequently, 37% of U.S. NGL production was exported in 2017. Canada, Japan, and China are currently the largest importers of U.S. NGLs.
The rapid growth of NGL production has also outpaced the development of supporting infrastructure. NGLs are expensive to transport and handle—requiring high pressures and low temperatures to keep them in a liquid state for shipment. A network of processing plants and distribution methods is necessary to move NGLs from well to market. Moreover, the surplus of NGLs brought upon by domestic production growth is increasing the need for infrastructure to aid in the exportation of NGLs internationally and the storage of NGLs domestically.
While energy production and consumption have been issues of interest to Congress for decades, the supply, consumption, environment, and trade of NGLs has become a topic of congressional interest more recently. Infrastructure, production, safety, and economics are all critical to the NGL market and may be of interest to Congress. Over 30 bills that relate to NGLs have been introduced in the 115th Congress. Proposed legislation has targeted issues related to NGL storage, infrastructure permitting, data collection, and safety, among others.