Enterprise Products Partners L.P. provides midstream energy services to producers and consumers of natural gas, natural gas liquids (NGLs), crude oil, petrochemicals, and refined products. It operates in four segments: NGL Pipelines & Services, Crude Oil Pipelines & Services, Natural Gas Pipelines & Services, and Petrochemical & Refined Products Services. The NGL Pipelines & Services segment offers natural gas processing and related NGL marketing services. It operates natural gas processing facilities located in Colorado, Louisiana, Mississippi, New Mexico, Texas, and Wyoming; NGL pipelines; NGL fractionation facilities; NGL and related product storage facilities; and NGL marine terminals. The Crude Oil Pipelines & Services segment operates crude oil pipelines; and crude oil storage and marine terminals, which include a fleet of approximately 250 tractor-trailer tank trucks that are used to transport crude oil. It also engages in crude oil marketing activities. The Natural Gas Pipelines & Services segment operates natural gas pipeline systems to gather, treat, and transport natural gas. It leases underground salt dome natural gas storage facilities in Napoleonville, Louisiana; owns an underground salt dome storage cavern in Wharton County, Texas; and markets natural gas. The Petrochemical & Refined Products Services segment operates propylene fractionation facilities, including propylene fractionation units and propane dehydrogenation facilities, and related marketing activities; butane isomerization complex and related deisobutanizer operations; and octane enhancement, isobutane dehydrogenation, and high purity isobutylene production facilities. It also operates refined products pipelines and terminals; and ethylene export terminals; and provides refined products marketing and marine transportation services. Enterprise Products Partners L.P. was founded in 1968 and is headquartered in Houston, Texas.

MPLX LP owns and operates midstream energy infrastructure and logistics assets primarily in the United States. It operates in two segments, Logistics and Storage, and Gathering and Processing. The company is involved in the gathering, processing, and transportation of natural gas; gathering, transportation, fractionation, storage, and marketing of natural gas liquids; gathering, storage, transportation, and distribution of crude oil and refined products, as well as other hydrocarbon-based products and renewables; and sale of residue gas and condensate. It also engages in the inland marine businesses comprising fleet of boats and barges transportation of light products, heavy oils, crude oil, renewable fuels, chemicals, and feedstocks in the Mid-Continent and Gulf Coast regions, as well as a marine repair facility located on the Ohio River; and distribution of fuel, as well as operates refining logistics, terminals, rail facilities, and storage caverns. In addition, the company operates terminal facilities for the receipt, storage, blending, additization, handling, and redelivery of refined petroleum products through the pipeline, rail, marine, and over-the-road modes of transportation. MPLX GP LLC acts as the general partner of MPLX LP. The company was incorporated in 2012 and is headquartered in Findlay, Ohio. MPLX LP operates as a subsidiary of Marathon Petroleum Corporation.

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.

EnLink Midstream, LLC provides midstream energy services in the United States. The company operates through Permian, Louisiana, Oklahoma, North Texas, and Corporate segments. It is involved in gathering, compressing, treating, processing, transporting, storing, and selling natural gas; fractionating, transporting, storing, and selling natural gas liquids; and gathering, transporting, stabilizing, storing, trans-loading, and selling crude oil and condensate, as well as providing brine disposal services. In addition, the company's midstream energy asset network includes natural gas processing plants; fractionators; barge and rail terminals; product storage facilities; and brine disposal wells. EnLink Midstream, LLC was incorporated in 2013 and is based in Dallas, Texas.

Plains GP Holdings, L.P., through its subsidiary, Plains All American Pipeline, L.P., owns and operates midstream infrastructure systems in the United States and Canada. It operates in two segments, Crude Oil and Natural Gas Liquids (NGLs). The company engages in the gathering and transporting crude oil and NGLs using pipelines, gathering systems, and trucks. It engages in the loading and unloading services at terminals; NGL fractionation and isomerization services; and natural gas and condensate processing services. The company offers logistics services to producers, refiners, and other customers. PAA GP Holdings LLC operates as a general partner of the company. Plains GP Holdings, L.P. was incorporated in 2013 and is headquartered in Houston, Texas.

Delek US Holdings, Inc. engages in the integrated downstream energy business in the United States. The company operates through Refining, Logistics, and Retail segments. The Refining segment processes crude oil and other feedstock for the manufacture of various grades of gasoline, diesel fuel, aviation fuel, asphalt, and other petroleum-based products that are distributed through owned and third-party product terminal. It owns and operates refineries located in Tyler, Texas; El Dorado, Arkansas; Big Spring, Texas; and Krotz Springs, Louisiana, as well as biodiesel facilities in Crossett, Arkansas, Cleburne, Texas, and New Albany, Mississippi. The Logistics segment gathers, transports, and stores crude oil, intermediate, and refined products; and markets, distributes, transports, and stores refined products, as well as disposes and recycles water for third parties. It owns or leases crude oil transportation pipelines, refined product pipelines, crude oil gathering systems, and associated crude oil storage tanks; and owns and operates light product distribution terminals, as well as markets light products using third-party terminals. The Retail segment owns and leases convenience store sites located primarily in West Texas and New Mexico. Its convenience stores offer various grades of gasoline and diesel under the DK or Alon brand; and food products and service, tobacco products, non-alcoholic and alcoholic beverages, and general merchandise, as well as money orders to the public primarily under the 7-Eleven and DK or Alon brand names. It serves oil companies, independent refiners and marketers, jobbers, distributors, utility and transportation companies, government, and independent retail fuel operators. Delek US Holdings, Inc. was founded in 2001 and is headquartered in Brentwood, Tennessee.

NGL Energy Partners LP engages in the transportation, storage, blending, and marketing of crude oil, natural gas liquids, refined products/renewables, and water solutions. The company operates through three segments: Water Solutions, Crude Oil Logistics, and Liquids Logistics. The Water Solutions segment transports, treats, recycles, and disposes produced and flowback water generated from crude oil and natural gas production; aggregates and sells recovered crude oil; disposes solids, such as tank bottoms, and drilling fluid and muds, as well as performs truck and frac tank washouts; and sells produced water for reuse and recycle, and brackish non-potable water. The Crude Oil Logistics segment purchases crude oil from producers and marketers, and transports it to refineries for resale at pipeline injection stations, storage terminals, barge loading facilities, rail facilities, refineries, and other trade hubs; and provides storage, terminaling, and transportation services through pipelines and storage tanks. The Liquids Logistics segment supplies natural gas liquids, refined petroleum products, and biodiesel to commercial, retail, and industrial customers in the United States and Canada through its 23 terminals, third-party storage and terminal facilities, and nine common carrier pipelines, as well as through a fleet of leased railcars. This segment also provides services for marine exports of butane through its facility located in Chesapeake, Virginia; and owns a propane pipeline in Michigan. NGL Energy Holdings LLC serves as the general partner of the company. The company was founded in 1940 and is headquartered in Tulsa, Oklahoma.

Martin Midstream Partners L.P., together with its subsidiaries, provides terminalling, processing, storage, and packaging services for petroleum products and by-products primarily in the United States. The company operates in four segments: Terminalling and Storage, Transportation, Sulfur Services, and Specialty Products. The company's Terminalling and Storage segment owns or operates various marine shore-based terminal facilities and specialty terminal facilities that provide storage, refining, blending, packaging, and handling services for producers and suppliers of petroleum products and by-products. This segment also offers land rental services to oil and gas companies, as well as storage and handling services for lubricants and fuels. Its Transportation segment operates various trucks and tank trailers; and inland marine tank barges, inland push boats, and articulated offshore tug and barge unit to transport petroleum products and by-products, petrochemicals, and chemicals. The company's Sulfur Services segment processes molten sulfur into prilled or pelletized sulfur, which is used in the production of fertilizers and industrial chemicals. Its Specialty Products segment stores, distributes, and transports natural gas liquids for wholesale deliveries to refineries, industrial natural gas liquid users, and propane retailers. Martin Midstream GP LLC serves as a general partner of the company. Martin Midstream Partners L.P. was incorporated in 2002 and is based in Kilgore, Texas.