The Williams Companies, Inc., together with its subsidiaries, operates as an energy infrastructure company primarily in the United States. It operates through Transmission & Gulf of Mexico, Northeast G&P, West, and Gas & NGL Marketing Services segments. The Transmission & Gulf of Mexico segment comprises natural gas pipelines; Transco, Northwest pipeline, MountainWest, and related natural gas storage facilities; and natural gas gathering and processing, and crude oil production handling and transportation assets in the Gulf Coast region. The Northeast G&P segment engages in the midstream gathering, processing, and fractionation activities in the Marcellus Shale region primarily in Pennsylvania and New York, and the Utica Shale region of eastern Ohio. The West segment consists of gas gathering, processing, and treating operations in the Rocky Mountain region of Colorado and Wyoming, the Barnett Shale region of north-central Texas, the Eagle Ford Shale region of South Texas, the Haynesville Shale region of northwest Louisiana, the Mid-Continent region that includes the Anadarko and Permian basins, and the DJ Basin of Colorado; and operates natural gas liquid (NGL) fractionation and storage facilities in central Kansas near Conway. The Gas & NGL Marketing Services segment provides wholesale marketing, trading, storage, and transportation of natural gas for natural gas utilities, municipalities, power generators, and producers; asset management services; and transports and markets NGLs. The company owns and operates 33,000 miles of pipelines. The Williams Companies, Inc. was founded in 1908 and is headquartered in Tulsa, Oklahoma.

Energy Transfer LP provides energy-related services. The company owns and operates natural gas transportation pipeline, and natural gas storage facilities in Texas and Oklahoma; and approximately 20,090 miles of interstate natural gas pipeline. It also sells natural gas to electric utilities, independent power plants, local distribution and other marketing companies, and industrial end-users. In addition, the company owns and operates natural gas gathering pipelines, processing plant, and treating and conditioning facilities in Texas, New Mexico, West Virginia, Pennsylvania, Ohio, Oklahoma, Arkansas, Kansas, Montana, North Dakota, Wyoming, and Louisiana; natural gas gathering, oil pipeline, and oil stabilization facilities in South Texas; and transports and supplies water to natural gas producer in Pennsylvania. Further, it owns 5,700 miles of natural gas liquid (NGL) pipeline; NGL fractionation facilities; NGL storage facilities; and other NGL storage assets and terminal. Additionally, the company provides crude oil transportation, terminalling, acquisition, and marketing activities; owns and operates approximately 14,500 miles of crude oil trunk and gathering pipelines in the Southwest, Midcontinent, and Midwest United States; and sells and distributes gasoline, middle distillate, and motor fuels and other petroleum products. It also offers natural gas compression services; carbon dioxide and hydrogen sulfide removal services; and manages coal and natural resources properties, as well as sells standing timber, leases coal-related infrastructure facilities, collects oil and gas royalty, and generate electrical power. The company was formerly known as Energy Transfer Equity, L.P. and changed its name to Energy Transfer LP in October 2018. Energy Transfer LP was founded in 1996 and is headquartered in Dallas, Texas.

ONEOK, Inc. engages in gathering, processing, fractionation, storage, transportation, and marketing of natural gas and natural gas liquids (NGL) in the United States. It operates through four segments: Natural Gas Gathering and Processing, Natural Gas Liquids, Natural Gas Pipelines, and Refined Products and Crude. The company owns natural gas gathering pipelines and processing plants in the Mid-Continent and Rocky Mountain regions; and provides midstream services to producers of NGLs. It also owns NGL gathering and distribution pipelines in Oklahoma, Kansas, Texas, New Mexico, Montana, North Dakota, Wyoming, and Colorado; terminal and storage facilities in Kansas, Nebraska, Iowa, and Illinois; NGL distribution pipelines in Kansas, Nebraska, Iowa, Illinois, and Indiana; transports refined petroleum products, including unleaded gasoline and diesel; and owns and operates truck- and rail-loading, and -unloading facilities connected to NGL fractionation, storage, and pipeline assets. In addition, the company transports and stores natural gas through regulated interstate and intrastate natural gas transmission pipelines, and natural gas storage facilities. Further, it owns and operates a parking garage in downtown Tulsa, Oklahoma; and leases excess office space and rail cars. Additionally, the company transports, stores, and distributes refined products, NGLs, and crude oil, as well as conducts commodity-related activities, including liquids blending and marketing activities. It serves integrated and independent exploration and production companies; other NGL and natural gas gathering and processing companies; crude oil and natural gas production companies; utilities; industrial companies; natural gasoline distributors; propane distributors; municipalities; ethanol producers; petrochemical, refining, and marketing companies; and heating fuel users, refineries, and exporters. ONEOK, Inc. was founded in 1906 and is headquartered in Tulsa, Oklahoma.

CenterPoint Energy, Inc. operates as a public utility holding company in the United States. The company operates through two segments, Electric and Natural Gas. The Electric segment includes electric transmission and distribution services to electric customers and electric generation assets, as well as optimizes assets in the wholesale power market. The Natural Gas segment engages in the intrastate natural gas sales, and natural gas transportation and distribution for residential, commercial, industrial and institutional customers in Indiana, Louisiana, Minnesota, Mississippi, Ohio, and Texas; permanent pipeline connections through interconnects with various interstate and intrastate pipeline companies; and provides maintenance and repair services of home appliances to customers in Minnesota and home repair protection plans to natural gas customers in Indiana, Mississippi, Ohio, and Texas through a third party. It serves approximately 2,534,730 metered customers; owned 348 substations with transformer capacity of 79,719 megavolt amperes; and owned and operated 217 miles of intrastate pipeline in Louisiana and Texas. The company was founded in 1866 and is headquartered in Houston, Texas.

Plains All American Pipeline, L.P., through its subsidiaries, engages in the pipeline transportation, terminaling, storage, and gathering of crude oil and natural gas liquids (NGL) in the United States and Canada. The company operates through two segments, Crude Oil and NGL. The Crude Oil segment offers gathering and transporting crude oil through pipelines, gathering systems, trucks, and on barges or railcars. This segment provides terminaling, storage, and other facilities-related services, as well as merchant activities. The NGL segment is involved in natural gas processing and NGL fractionation, storage, transportation, and terminaling. This segment also includes ethane, propane, normal butane, iso-butane, and natural gasoline derived from natural gas production and processing activities, as well as crude oil refining processes. Its NGL components are used for various applications, such as heating, engine, and industrial fuels. The company was founded in 1981 and is headquartered in Houston, Texas. Plains All American Pipeline, L.P. operates as a subsidiary of Plains GP Holdings, L.P.

UGI Corporation, together with its subsidiaries, distributes, stores, transports, and markets energy products and related services in the United States and internationally. The company operates through four segments: AmeriGas Propane, UGI International, Midstream & Marketing, and UGI Utilities. It distributes propane to approximately 1.3 million residential, commercial/industrial, motor fuel, agricultural, and wholesale customers through 1,400 propane distribution locations. The company distributes liquefied petroleum gases (LPG) to residential, commercial, industrial, agricultural, wholesale and automobile fuel customers; and provides logistics, storage, and other services to third-party LPG distributors. In addition, it engages in the retail sale of natural gas, liquid fuels, and electricity to approximately 12,400 residential, commercial, and industrial customers at 42,000 locations. Further, the company distributes natural gas to approximately 677,000 customers in eastern and central Pennsylvania counties through its distribution system of approximately 12,500 miles of gas mains; and supplies electricity to approximately 62,600 customers in northeastern Pennsylvania through 2,560 miles of lines and 14 substations. Additionally, it operates electric generation facilities, which include coal-fired, landfill gas-fueled, solar-powered, and natural gas-fueled facilities; a natural gas liquefaction, storage, and vaporization facility; propane storage and propane-air mixing stations; and rail transshipment terminals. It manages natural gas pipeline and storage contracts; develops, owns, and operates pipelines, gathering infrastructure, and gas storage facilities. UGI Corporation was incorporated in 1882 and is headquartered in King of Prussia, Pennsylvania.

ONE Gas, Inc., together with its subsidiaries, operates as a regulated natural gas distribution company in the United States. The company provides natural gas distribution services to approximately 2.3 million customers in Oklahoma, Kansas, and Texas. It serves residential, commercial, and transportation customers. The company was founded in 1906 and is headquartered in Tulsa, Oklahoma.

Tellurian Inc. engages in the natural gas business worldwide. It operates through three segments: The Upstream, The Midstream, and The Marketing & Trading. The company produces, gathers, purchases, sells, and delivers natural gas; acquires and develops natural gas assets; and develops, constructs, and operates liquefied natural gas terminals and pipelines. The company was incorporated in 1957 and is headquartered in Houston, Texas.