Oneok
| File:ONEOK Logo .svg | |
| Company type | Public |
|---|---|
| Industry | Oil and gas |
| Founded | 1906 |
| Founders |
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| Headquarters | , U.S. |
Key people |
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| Products | |
| Services |
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| Revenue | Increase Template:US$ (2024) |
| Increase Template:US$ (2024) | |
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| Total assets | Increase Template:US$ (2024) |
| Total equity | Increase Template:US$ (2024) |
Number of employees | 5,177 (2024) |
| Subsidiaries | |
| Website | oneok |
Oneok, Inc. (), branded as ONEOK, is a midstream operator in the American oil and natural gas sector headquartered in Tulsa. The company specializes in gathering, processing, fractionation, transportation, and storage services for the oil and gas industry. Publicly traded on the NYSE, Oneok is included in both the Fortune 500 and S&P 500 indexes. Established in 1906 under the name Oklahoma Natural Gas Company by entrepreneurs Ryan C. Haynes and C.B. Ames, it adopted the Oneok name in 1980.
History
Pipeline construction commenced for Oklahoma Natural Gas Company in 1907, shortly after Oklahoma achieved statehood, with a $1.7 million project linking Osage County to Oklahoma City. By 1919, the company operated over 1,000 miles of pipeline serving 37 communities; by 1956, it had grown to 600 employees managing approximately 6,600 miles of pipeline infrastructure.
In December 1980, the firm rebranded as Oneok Inc., while its original gas service operations continued under the Oklahoma Natural Gas name.
Expansion through acquisitions began in the mid-1990s: in 1996, Oneok acquired Western Resources' natural gas pipelines and processing plants via a $660 million stock transaction, adding around 1,575 staff and serving more than 660,000 customers across Kansas and Oklahoma. A proposed $1.8 billion merger with Southwest Gas in 1999 was terminated in 2000 following legal challenges.
In 2002, Oneok purchased Southern Union Gas's Texas division for $420 million and rebranded it as Texas Gas Service. The acquisition of Northern Plains Natural Gas Co. occurred in 2004 for $175 million, which included control over Northern Border Partners’ extensive pipeline and processing assets.
Oneok separated its natural gas distribution units—including Oklahoma Natural Gas Co., Kansas Gas Service, and Texas Gas Service—into a new entity called One Gas in July 2013.
After delays due to the COVID-19 pandemic, construction on the Demicks Lake III natural gas processing plant in North Dakota resumed in late 2021, with operations commencing in February 2023.
Following an explosion at its Medford, Oklahoma facility in July 2022—which caused no injuries but temporarily displaced about 1,000 residents—Oneok resolved insurance claims totaling $930 million by January 2023 and announced intentions to relocate fractionation activities away from that location.
In September 2023, Oneok completed an $18.8 billion acquisition of Magellan Midstream Partners, thereby acquiring significant crude oil terminals and trading hubs situated in Texas locations such as East Houston, Galena Park, Seabrook, and Pasadena.
In May 2024, Oneok agreed to purchase Gulf Coast NGL Pipelines from Easton Energy for $280 million, adding approximately 450 miles of pipeline along Texas and Louisiana’s Gulf Coast region. Later that year, in November, it divested three pipelines—Guardian Pipeline, Midwestern Gas Transmission, and Viking Gas Transmission—to DT Midstream for $1.2 billion.
Toward the end of 2024, Oneok notably increased its footprint in the Permian Basin by acquiring Medallion Midstream—a crude oil gathering and transportation company—and obtaining majority control of EnLink Midstream. By February 2025, Oneok finalized acquisition of all outstanding shares of EnLink Midstream.
In May 2025, Oneok secured complete ownership of a Delaware Basin joint venture previously co-managed with NGP XI Midstream Holdings through a $940 million transaction. This acquisition granted operational control over infrastructure that processes roughly 700 million cubic feet of natural gas daily within the Delaware Basin area.
Operations
Oneok conducts its business through four principal divisions: natural gas liquids, natural gas gathering and processing, natural gas pipelines, and refined products along with crude oil. Its extensive pipeline infrastructure features significant assets such as the Northern Border Pipeline, the Roadrunner Gas Transmission Pipeline, the Arbuckle Pipeline, and the Elk Creek Pipeline, all of which play a vital role in expanding its market access and sustaining its competitive position.
In alignment with its growth strategy, Oneok acquired Magellan Midstream Partners, which now operates as a subsidiary overseeing nearly 2,200 miles of crude oil pipelines. Among these assets is the 450-mile Longhorn pipeline, which moves roughly 275,000 barrels daily from the Permian Basin to refining centers in Houston, thereby strengthening Oneok’s presence in crude oil transportation and logistics.