Exhibit 99.1 
 
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 News 
 
 
 
 
 
ONEOK to Expand Infrastructure to Serve STACK Growth 
 
TULSA, Okla. – June 19, 2017 – ONEOK, Inc. (NYSE: OKE) today announced plans to 
expand its Mid-Continent natural gas liquids (NGL) gathering system and its existing Sterling III 
Pipeline. The expansions, which are backed by a long-term contract with a subsidiary of EnLink 
Midstream Partners, LP and EnLink Midstream, LLC (EnLink), will help accommodate expected 
volume growth from current and certain future EnLink natural gas processing plants in the 
STACK play in western Oklahoma along with expected growth from other customers in the 
region.  
 
“Producers continue to accelerate their investments in the STACK due to the higher-
 return economics driven by strong crude oil and NGL-rich natural gas production rates,” said 
Terry K. Spencer, ONEOK president and chief executive officer. “This expansion of our NGL 
gathering system further underscores our ability to meet the NGL service needs of STACK-area 
natural gas processors and demonstrates our continued commitment to providing reliable high-
 quality service to our customers.” 
 
Expansions include increasing capacity on the Sterling III Pipeline to 250,000 barrels per 
day (bpd) from 190,000 bpd and connecting ONEOK’s Arbuckle Pipeline to EnLink’s Cajun-
 Sibon Pipeline in southeast Texas. ONEOK’s Sterling III Pipeline transports either 
unfractionated NGLs or NGL purity products between ONEOK’s Mid-Continent NGL 
infrastructure and similar facilities on the Gulf Coast in Mont Belvieu, Texas.  
 
ONEOK expects to invest approximately $130 million for these projects, which are 
expected to be complete by the end of 2018.   
 
ONEOK’s natural gas liquids segment currently gathers 150,000 to 200,000 bpd of NGLs 
out of the STACK and SCOOP plays and is connected to more than 100 third-party natural gas 
processing plants in the Mid-Continent. The NGL volumes from the EnLink plant connections 
and other production are part of an incremental 100,000 bpd of expected NGL supply out of the 
STACK and SCOOP plays that ONEOK expects to add to its system by the end of 2018.  
In addition, to support the increasing producer activity in the STACK and SCOOP on 
dedicated acreage in the natural gas gathering and processing segment, ONEOK has entered into 
June 19, 2017     Analyst Contact: Megan Patterson 
         918-561-5325 
       Media Contact: Brad Borror 
                   918-588-7582
 ONEOK to Expand Infrastructure to Serve STACK Growth 
 
June 19, 2017 
 
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a long-term processing services agreement with a third party to gain access to an additional 200 
million cubic feet per day (MMcf/d) of natural gas processing capacity in this region.  
 
“This agreement provides an atrractive option for timely access to existing natural gas 
processing capacity to better serve the rapid growth occurring on our dedicated acreage,” 
Spencer added. 
ONEOK plans to connect its extensive natural gas gathering system to the existing third-
 party natural gas processing facility in northern Oklahoma by constructing a nearly 30-mile 
natural gas gathering pipeline and related infrastructure through the core of the STACK play in 
Blaine County, Oklahoma. The pipeline is expected to cost approximately $40 million and be 
completed by the end of 2017. 
 
This third-party plant already is connected to ONEOK’s existing NGL gathering system 
and is expected to provide incremental NGL volumes as natural gas processing volumes 
increase.  
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ONEOK, Inc. (pronounced ONE-OAK) (NYSE: OKE) is the general partner and as of March 31, 2017, owns 41.2 
percent of ONEOK Partners, L.P. (NYSE: OKS), one of the largest publicly traded master limited partnerships, which 
owns one of the nation's premier natural gas liquids (NGL) systems, connecting NGL supply in the Mid-Continent, 
Permian and Rocky Mountain regions with key market centers and is a leader in the gathering, processing, storage 
and transportation of natural gas in the U.S. ONEOK is a FORTUNE 500 company and is included in Standard & 
Poor's (S&P) 500 index. 
 
For more information, visit the websites at www.oneok.com or www.oneokpartners.com. 
 
For the latest news about ONEOK and ONEOK Partners, follow us on Twitter @ONEOKNews and 
@ONEOKPartners. 
 
Some of the statements contained and incorporated in this news release are forward-looking statements as defined 
under federal securities laws. The forward-looking statements relate to our anticipated financial performance, liquidity, 
management's plans and objectives for our growth projects and other future operations (including plans to construct 
additional natural gas and natural gas liquids pipelines), our business prospects, the outcome of regulatory and legal 
proceedings, market conditions and other matters.  We make these forward-looking statements in reliance on the 
safe harbor protections provided under federal securities laws and other applicable laws. 
 
Forward-looking statements include the items identified in the preceding paragraph, the information concerning 
possible or assumed future results of our operations and other statements contained or incorporated in this news 
release identified by words such as “anticipate,” “estimate,” “expect,” “project,” “intend,” “plan,” “believe,” “should,” 
“goal,” “forecast,” “guidance,” “could,” “may,” “continue,” “might,” “potential,” “scheduled” and other words and terms 
of similar meaning.  
 
One should not place undue reliance on forward-looking statements. Known and unknown risks, uncertainties and 
other factors may cause our actual results, performance or achievements to be materially different from any future 
results, performance or achievements expressed or implied by forward-looking statements. Those factors may affect 
our operations, markets, products, services and prices. These and other risks are described in greater detail in Item 
1A, Risk Factors, in our most recent Annual Report on Form 10-K and in the other filings that we make with the 
Securities and Exchange Commission (SEC), which are available on the SEC’s website at www.sec.gov. All forward-
 looking statements attributable to us or persons acting on our behalf are expressly qualified in their entirety by these 
factors. Any such forward-looking statement speaks only as of the date on which such statement is made, and, other 
than as required under securities laws, we undertake no obligation to update publicly any forward-looking statement 
whether as a result of new information, subsequent events or change in circumstances, expectations or otherwise.