----

|             |
|-------------|
|             |  |  |  |
| May 2, 2017 |   | Analyst Contact: | Megan Patterson918-561-5325 |
|        |   | Media Contact: | Brad Borror918-588-7582 |

|         |                                                                                                                                                                                                                                           |
|---------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | First-quarter 2017 net income attributable to ONEOK Partners and adjusted earnings before interest, taxes, depreciation and amortization (adjusted EBITDA) increased 6 and 4 percent, respectively, compared with the first quarter 2016; |

|         |                                                          |
|---------|----------------------------------------------------------|
| • | First-quarter 2017 distribution coverage ratio was 1.10; |

|         |                                                                                                                                                                                  |
|---------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | The natural gas gathering and processing segment’s average fee rate increased to 83 cents in the first quarter 2017, compared with 68 cents in the first quarter 2016; and |

|         |                                                                                                                                                                  |
|---------|------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | The natural gas liquids segment connected three new third-party natural gas processing plants to its natural gas liquids (NGL) system in the first quarter 2017. |

|                                                                                                                                                                                         |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|                                                                                                                                                                                         |  |  |  |  |  |  |  |
|                                                                                                                                                                                    | Three Months Ended |
|                                                                                                                                                                                    | March 31, |
| ONEOK Partners                                                                                                                                                                          | 2017 |   | 2016 |
|                                                                                                                                                                                    | (Millions of dollars, except per unit and coverage ratio amounts) |
| Net income attributable to ONEOK Partners                                                                                                                                               | $ | 269.1 |  |   | $ | 253.5 |  |
| Net income per limited partner unit                                                                                                                                                     | $ | 0.57 |  |   | $ | 0.52 |  |
| Adjusted EBITDA (a)                                                                                                                                                                     | $ | 464.2 |  |   | $ | 444.6 |  |
| DCF (a)                                                                                                                                                                                 | $ | 355.4 |  |   | $ | 347.6 |  |
| Distribution coverage ratio (a)                                                                                                                                                         | 1.10 |  |   | 1.06 |  |
| (a) Adjusted EBITDA; distributable cash flow (DCF); and distribution coverage ratio are non-GAAP measures. Reconciliations to relevant GAAP measures are attached to this news release. |

----

----

|                                         |
|-----------------------------------------|
|                                         |  |  |  |  |  |  |  |
|                                    | Three Months Ended |
|                                    | March 31, |
| ONEOK Partners                          | 2017 |   | 2016 |
|                                    | (Millions of dollars) |
| Operating income                        | $ | 324.4 |  |   | $ | 318.2 |  |
| Operating costs                         | $ | 182.2 |  |   | $ | 170.4 |  |
| Depreciation and amortization           | $ | 98.6 |  |   | $ | 93.7 |  |
| Equity in net earnings from investments | $ | 39.6 |  |   | $ | 32.9 |  |
| Adjusted EBITDA                         | $ | 464.2 |  |   | $ | 444.6 |  |
| Capital expenditures                    | $ | 112.6 |  |   | $ | 195.9 |  |

|         |                                                                                                                     |
|---------|---------------------------------------------------------------------------------------------------------------------|
| • | Higher average fee rates resulting from contract restructuring in the natural gas gathering and processing segment; |

|         |                                                                                             |
|---------|---------------------------------------------------------------------------------------------|
| • | Higher firm demand charge transportation revenues in the natural gas pipelines segment; and |

|         |                                                                                                                                              |
|---------|----------------------------------------------------------------------------------------------------------------------------------------------|
| • | Increased transportation and exchange service volumes and wider location and product price differentials in the natural gas liquids segment. |

----

|         |                                                                                                                                                 |
|---------|-------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Announcing on Feb. 1, 2017, an agreement under which ONEOK will acquire the outstanding common units of ONEOK Partners it does not already own; |

|         |                                                                                                                                                                              |
|---------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Reporting first-quarter 2017 net income attributable to ONEOK Partners and adjusted EBITDA increases of 6 and 4 percent, respectively, compared with the first quarter 2016; |

|         |                                                                   |
|---------|-------------------------------------------------------------------|
| • | Reporting first-quarter 2017 distribution coverage of 1.10 times; |

|         |                                                                                                                                                                                             |
|---------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Connecting three additional third-party natural gas processing plants - one each in the Permian Basin, Mid-Continent and Rocky Mountain region - to the partnership’s NGL system; and |

|         |                                                                                                                           |
|---------|---------------------------------------------------------------------------------------------------------------------------|
| • | Declaring in April 2017 a first-quarter 2017 distribution of 79 cents per unit, or $3.16 per unit on an annualized basis. |

|                             |
|-----------------------------|
|                             |  |  |  |  |  |  |  |
|                        | Three Months Ended |
|                        | March 31, |
| Natural Gas Liquids Segment | 2017 |   | 2016 |
|                        | (Millions of dollars) |
| Adjusted EBITDA             | $ | 278.2 |  |   | $ | 270.2 |  |
| Capital expenditures        | $ | 20.5 |  |   | $ | 34.2 |  |

----

|         |                                                                                                            |
|---------|------------------------------------------------------------------------------------------------------------|
| • | A $5.3 million increase in optimization and marketing due primarily to wider location price differentials; |

|         |                                                                                                                                                                                 |
|---------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | A $3.9 million increase in transportation and storage services due to higher distribution pipeline volumes and higher storage and terminaling revenue in the Gulf Coast region; |

|         |                                                                                                                                                                                                                                                                                                                                                                                                                             |
|---------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | A $3.6 million increase due to wider product price differentials, increased exchange-service volumes from recently connected natural gas processing plants primarily in the Williston Basin, increased ethane recovery and increased volumes gathered in the STACK and SCOOP areas, offset partially by decreased volumes gathered from the Barnett Shale and lower rates on the West Texas LPG system; offset partially by |

|         |                                                                                                                      |
|---------|----------------------------------------------------------------------------------------------------------------------|
| • | A $5.5 million increase in operating costs due primarily to higher property taxes and higher employee-related costs. |

|                                              |
|----------------------------------------------|
|                                              |  |  |  |  |  |  |  |
|                                         | Three Months Ended |
|                                         | March 31, |
| Natural Gas Gathering and Processing Segment | 2017 |   | 2016 |
|                                         | (Millions of dollars) |
| Adjusted EBITDA                              | $ | 104.0 |  |   | $ | 100.0 |  |
| Capital expenditures                         | $ | 63.2 |  |   | $ | 141.5 |  |

|         |                                                                                                                                                                                                                                                                    |
|---------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | A $19.8 million increase due primarily to restructured contracts resulting in higher average fee rates, offset partially by a lower percentage of proceeds (POP) retained from the sale of commodities purchased under POP with fee contracts; offset partially by |

|         |                                                                                                                            |
|---------|----------------------------------------------------------------------------------------------------------------------------|
| • | A $10.2 million decrease due primarily to lower volumes as a result of severe winter weather in the first quarter of 2017; |

|         |                                                                                 |
|---------|---------------------------------------------------------------------------------|
| • | A $2.4 million decrease due primarily to lower realized natural gas prices; and |

----

|         |                                                                                                                                                                    |
|---------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | A $2.2 million increase in operating costs due primarily to increased labor and higher employee-related costs, partially offset by lower outside service expenses. |

|                                                        |
|--------------------------------------------------------|
|                                                        |  |  |  |  |  |
|                                                   | Three Months Ended |
|                                                   | March 31, |
| Equity-Volume Information (a)                          | 2017 |   | 2016 |
| NGL sales - including ethane (MBbl/d)                  | 9.8 |  |   | 16.4 |  |
| Condensate sales (MBbl/d)                              | 3.1 |  |   | 2.7 |  |
| Residue natural gas sales (BBtu/d)                     | 71.1 |  |   | 83.8 |  |
| (a) - Includes volumes for consolidated entities only. |   |   |   |

|                               |
|-------------------------------|
|                               |  |  |  |  |  |  |  |
|                          | Three Months Ended |
|                          | March 31, |
| Natural Gas Pipelines Segment | 2017 |   | 2016 |
|                          | (Millions of dollars) |
| Adjusted EBITDA               | $ | 83.0 |  |   | $ | 74.3 |  |
| Capital expenditures          | $ | 25.0 |  |   | $ | 17.9 |  |

----

|         |                                                                                                                                    |
|---------|------------------------------------------------------------------------------------------------------------------------------------|
| • | A $9.9 million increase from higher transportation services due primarily to increased firm demand charge capacity contracted; and |

|         |                                                                                                                                                                         |
|---------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | A $6.4 million increase in equity in net earnings from investments due primarily to higher firm transportation revenues on the Roadrunner pipeline; offset partially by |

|         |                                                                                                                          |
|---------|--------------------------------------------------------------------------------------------------------------------------|
| • | A $4.3 million increase in operating costs due primarily to higher property taxes and higher employee-related costs; and |

|         |                                                                                                           |
|---------|-----------------------------------------------------------------------------------------------------------|
| • | A $3.0 million decrease due to gains on sales of excess natural gas in storage in the first quarter 2016. |

----

|         |                                                                                                                                                                                                                                                                              |
|---------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Adjusted EBITDA is defined as net income adjusted for interest expense, net of capitalized interest, depreciation and amortization, impairment charges, income taxes and allowance for equity funds used during construction (equity AFUDC) and certain other noncash items; |

|         |                                                                                                                                                                                                                                                                       |
|---------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | DCF is defined as adjusted EBITDA, computed as described above, less interest expense, maintenance capital expenditures and equity earnings from investments, excluding noncash impairment charges, adjusted for cash distributions received and certain other items; |

|         |                                                                                                                                                                                                                                          |
|---------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Distributable cash flow to limited partners per limited partner unit is computed as DCF less distributions declared to the general partner in the period, divided by the weighted-average number of units outstanding in the period; and |

|         |                                                                                                                                                                                              |
|---------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Distribution coverage ratio is defined as distributable cash flow to limited partners per limited partner unit divided by the distribution declared per limited partner unit for the period. |

----

----

|         |                                                                                                                                     |
|---------|-------------------------------------------------------------------------------------------------------------------------------------|
| • | the ability to obtain the requisite ONEOK stockholder and ONEOK Partners unitholder approvals relating to the proposed transaction; |

|         |                                                                                                                                                                                                                                                                                                                                                              |
|---------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | the risk that ONEOK or ONEOK Partners may be unable to obtain governmental and regulatory approvals required for the proposed transaction, if any, or required governmental and regulatory approvals, if any, may delay the proposed transaction or result in the imposition of conditions that could cause the parties to abandon the proposed transaction; |

|         |                                                                                        |
|---------|----------------------------------------------------------------------------------------|
| • | the risk that a condition to closing of the proposed transaction may not be satisfied; |

|         |                                                    |
|---------|----------------------------------------------------|
| • | the timing to consummate the proposed transaction; |

|         |                                                                                                                                                              |
|---------|--------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | the risk that cost savings, tax benefits and any other synergies from the transaction may not be fully realized or may take longer to realize than expected; |

|         |                                                                                                                              |
|---------|------------------------------------------------------------------------------------------------------------------------------|
| • | disruption from the transaction may make it more difficult to maintain relationships with customers, employees or suppliers; |

|         |                                                                     |
|---------|---------------------------------------------------------------------|
| • | the possible diversion of management time on merger-related issues; |

|         |                                                                                                                              |
|---------|------------------------------------------------------------------------------------------------------------------------------|
| • | the impact and outcome of pending and future litigation, including litigation, if any, relating to the proposed transaction; |

|         |                                                                                                                                             |
|---------|---------------------------------------------------------------------------------------------------------------------------------------------|
| • | the effects of weather and other natural phenomena, including climate change, on our operations, demand for our services and energy prices; |

|         |                                                                                                                                                                                                                                                   |
|---------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | competition from other United States and foreign energy suppliers and transporters, as well as alternative forms of energy, including, but not limited to, solar power, wind power, geothermal energy and biofuels such as ethanol and biodiesel; |

|         |                                                 |
|---------|-------------------------------------------------|
| • | the capital intensive nature of our businesses; |

|         |                                                                          |
|---------|--------------------------------------------------------------------------|
| • | the profitability of assets or businesses acquired or constructed by us; |

|         |                                                        |
|---------|--------------------------------------------------------|
| • | our ability to make cost-saving changes in operations; |

|         |                                                                                                                                                       |
|---------|-------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | risks of marketing, trading and hedging activities, including the risks of changes in energy prices or the financial condition of our counterparties; |

|         |                                                                                          |
|---------|------------------------------------------------------------------------------------------|
| • | the uncertainty of estimates, including accruals and costs of environmental remediation; |

----

|         |                                                              |
|---------|--------------------------------------------------------------|
| • | the timing and extent of changes in energy commodity prices; |

|         |                                                                                                                                                                                                                                                                                               |
|---------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | the effects of changes in governmental policies and regulatory actions, including changes with respect to income and other taxes, pipeline safety, environmental compliance, climate change initiatives and authorized rates of recovery of natural gas and natural gas transportation costs; |

|         |                                                                                                                                                                                                                                                                                                                                            |
|---------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | the impact on drilling and production by factors beyond our control, including the demand for natural gas and crude oil; producers' desire and ability to obtain necessary permits; reserve performance; and capacity constraints on the pipelines that transport crude oil, natural gas and NGLs from producing areas and our facilities; |

|         |                                                                                                                                    |
|---------|------------------------------------------------------------------------------------------------------------------------------------|
| • | difficulties or delays experienced by trucks, railroads or pipelines in delivering products to or from our terminals or pipelines; |

|         |                                                                                                                                        |
|---------|----------------------------------------------------------------------------------------------------------------------------------------|
| • | changes in demand for the use of natural gas, NGLs and crude oil because of market conditions caused by concerns about climate change; |

|         |                                                         |
|---------|---------------------------------------------------------|
| • | conflicts of interest between ONEOK and ONEOK Partners; |

|         |                                                                                                                                                                                                                                                                                                            |
|---------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | the impact of unforeseen changes in interest rates, debt and equity markets, inflation rates, economic recession and other external factors over which we have no control, including the effect on pension and postretirement expense and funding resulting from changes in stock and bond market returns; |

|         |                                                                                                                                                                                                                                                                                 |
|---------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | our indebtedness could make us vulnerable to general adverse economic and industry conditions, limit our ability to borrow additional funds and/or place us at competitive disadvantages compared with our competitors that have less debt, or have other adverse consequences; |

|         |                                                                                       |
|---------|---------------------------------------------------------------------------------------|
| • | actions by rating agencies concerning the credit ratings of ONEOK and ONEOK Partners; |

|         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
|---------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | the results of administrative proceedings and litigation, regulatory actions, rule changes and receipt of expected clearances involving any local, state or federal regulatory body, including the Federal Energy Regulatory Commission (FERC), the National Transportation Safety Board, the Pipeline and Hazardous Materials Safety Administration (PHMSA), the U.S. Environmental Protection Agency (EPA) and the U.S. Commodity Futures Trading Commission (CFTC); |

|         |                                                                                  |
|---------|----------------------------------------------------------------------------------|
| • | our ability to access capital at competitive rates or on terms acceptable to us; |

|         |                                                                                                                                                                                                             |
|---------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | risks associated with adequate supply to our gathering, processing, fractionation and pipeline facilities, including production declines that outpace new drilling or extended periods of ethane rejection; |

|         |                                                                                                                                                                               |
|---------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | the risk that material weaknesses or significant deficiencies in our internal controls over financial reporting could emerge or that minor problems could become significant; |

|         |                                                                                       |
|---------|---------------------------------------------------------------------------------------|
| • | the ability to market pipeline capacity on favorable terms, including the effects of: |

|         |                                                                  |
|---------|------------------------------------------------------------------|
| • | future demand for and prices of natural gas, NGLs and crude oil; |

|         |                                                      |
|---------|------------------------------------------------------|
| • | competitive conditions in the overall energy market; |

|         |                                                                                       |
|---------|---------------------------------------------------------------------------------------|
| • | availability of supplies of Canadian and United States natural gas and crude oil; and |

|         |                                              |
|---------|----------------------------------------------|
| • | availability of additional storage capacity; |

|         |                                                                                                       |
|---------|-------------------------------------------------------------------------------------------------------|
| • | performance of contractual obligations by our customers, service providers, contractors and shippers; |

|         |                                                                                                                                                                          |
|---------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | the timely receipt of approval by applicable governmental entities for construction and operation of our pipeline and other projects and required regulatory clearances; |

|         |                                                                                                                                                                                                                                                                                                                     |
|---------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | our ability to acquire all necessary permits, consents or other approvals in a timely manner, to promptly obtain all necessary materials and supplies required for construction, and to construct gathering, processing, storage, fractionation and transportation facilities without labor or contractor problems; |

|         |                                                  |
|---------|--------------------------------------------------|
| • | the mechanical integrity of facilities operated; |

|         |                                                             |
|---------|-------------------------------------------------------------|
| • | demand for our services in the proximity of our facilities; |

|         |                                         |
|---------|-----------------------------------------|
| • | our ability to control operating costs; |

|         |                                                                                                                                          |
|---------|------------------------------------------------------------------------------------------------------------------------------------------|
| • | acts of nature, sabotage, terrorism or other similar acts that cause damage to our facilities or our suppliers' or shippers' facilities; |

|         |                                                                              |
|---------|------------------------------------------------------------------------------|
| • | economic climate and growth in the geographic areas in which we do business; |

|         |                                                                                                                                                                              |
|---------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | the risk of a prolonged slowdown in growth or decline in the United States or international economies, including liquidity risks in United States or foreign credit markets; |

----

|         |                                                                                                       |
|---------|-------------------------------------------------------------------------------------------------------|
| • | the impact of recently issued and future accounting updates and other changes in accounting policies; |

|         |                                                                                                                                                                                                     |
|---------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | the possibility of future terrorist attacks or the possibility or occurrence of an outbreak of, or changes in, hostilities or changes in the political conditions in the Middle East and elsewhere; |

|         |                                                                                                                    |
|---------|--------------------------------------------------------------------------------------------------------------------|
| • | the risk of increased costs for insurance premiums, security or other items as a consequence of terrorist attacks; |

|         |                                                                                                                                                                                                                                                                             |
|---------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | risks associated with pending or possible acquisitions and dispositions, including our ability to finance or integrate any such acquisitions and any regulatory delay or conditions imposed by regulatory bodies in connection with any such acquisitions and dispositions; |

|         |                                                                                        |
|---------|----------------------------------------------------------------------------------------|
| • | the impact of uncontracted capacity in our assets being greater or less than expected; |

|         |                                                                                                                                                                                    |
|---------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | the ability to recover operating costs and amounts equivalent to income taxes, costs of property, plant and equipment and regulatory assets in our state and FERC-regulated rates; |

|         |                                                                                                                             |
|---------|-----------------------------------------------------------------------------------------------------------------------------|
| • | the composition and quality of the natural gas and NGLs we gather and process in our plants and transport on our pipelines; |

|         |                                                                                               |
|---------|-----------------------------------------------------------------------------------------------|
| • | the efficiency of our plants in processing natural gas and extracting and fractionating NGLs; |

|         |                                             |
|---------|---------------------------------------------|
| • | the impact of potential impairment charges; |

|         |                                                                                                                                                                                                         |
|---------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | the risk inherent in the use of information systems in our respective businesses, implementation of new software and hardware, and the impact on the timeliness of information for financial reporting; |

|         |                                                                                                             |
|---------|-------------------------------------------------------------------------------------------------------------|
| • | our ability to control construction costs and completion schedules of our pipelines and other projects; and |

|         |                                                                                                                                                                                                                                                                                                                                           |
|---------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | the ability of management to execute its plans to meet its goals and other risks inherent in our businesses that are discussed in ONEOK's and ONEOK Partners’ most recent annual reports on Form 10-K, respectively, and in other ONEOK and ONEOK Partners reports on file with the Securities and Exchange Commission (the "SEC"). |

----

----

|                                                                                   |
|-----------------------------------------------------------------------------------|
|                                                                                   |  |  |  |  |  |  |  |  |
| ONEOK Partners, L.P. and Subsidiaries                                             |   |   |   |   |
| CONSOLIDATED STATEMENTS OF INCOME                                                 |   |   |   |   |
|                                                                              |   | Three Months Ended |
|                                                                              |   | March 31, |
| (Unaudited)                                                                       |   | 2017 |   | 2016 |
|                                                                              |   | (Thousands of dollars, except per unit amounts) |
| Revenues                                                                          |   |   |   |   |
| Commodity sales                                                                   |   | $ | 2,216,717 |  |   | $ | 1,283,511 |  |
| Services                                                                          |   | 532,356 |  |   | 490,434 |  |
| Total revenues                                                                    |   | 2,749,073 |  |   | 1,773,945 |  |
| Cost of sales and fuel (exclusive of items shown separately below)                |   | 2,143,843 |  |   | 1,195,738 |  |
| Operations and maintenance                                                        |   | 155,282 |  |   | 148,740 |  |
| Depreciation and amortization                                                     |   | 98,626 |  |   | 93,736 |  |
| General taxes                                                                     |   | 26,892 |  |   | 21,640 |  |
| (Gain) loss on sale of assets                                                     |   | 7 |  |   | (4,145 | ) |
| Operating income                                                                  |   | 324,423 |  |   | 318,236 |  |
| Equity in net earnings from investments                                           |   | 39,564 |  |   | 32,914 |  |
| Allowance for equity funds used during construction                               |   | 13 |  |   | 208 |  |
| Other income                                                                      |   | 1,253 |  |   | 145 |  |
| Other expense                                                                     |   | (683 | ) |   | (634 | ) |
| Interest expense (net of capitalized interest of $1,441 and $2,887, respectively) |   | (90,707 | ) |   | (92,555 | ) |
| Income before income taxes                                                        |   | 273,863 |  |   | 258,314 |  |
| Income taxes                                                                      |   | (3,837 | ) |   | (2,028 | ) |
| Net income                                                                        |   | 270,026 |  |   | 256,286 |  |
| Less:  Net income attributable to noncontrolling interests                        |   | 905 |  |   | 2,769 |  |
| Net income attributable to ONEOK Partners, L.P.                                   |   | $ | 269,121 |  |   | $ | 253,517 |  |
| Limited partners’ interest in net income:                                   |   |   |  |   |   |  |
| Net income attributable to ONEOK Partners, L.P.                                   |   | $ | 269,121 |  |   | $ | 253,517 |  |
| General partner’s interest in net income                                    |   | (105,920 | ) |   | (105,608 | ) |
| Limited partners’ interest in net income                                    |   | $ | 163,201 |  |   | $ | 147,909 |  |
| Limited partners’ net income per unit, basic and diluted                    |   | $ | 0.57 |  |   | $ | 0.52 |  |
| Number of units used in computation (thousands)                                   |   | 285,826 |  |   | 285,826 |  |
| Distributions declared per limited partner unit                                   |   | $ | 0.79 |  |   | $ | 0.79 |  |

----

|                                                                                                |
|------------------------------------------------------------------------------------------------|
|                                                                                                |  |  |  |  |  |  |  |  |
| ONEOK Partners, L.P. and Subsidiaries                                                          |   |   |   |   |
| CONSOLIDATED BALANCE SHEETS                                                                    |   |   |   |   |
|                                                                                           |   | March 31, |   | December 31, |
| (Unaudited)                                                                                    |   | 2017 |   | 2016 |
| Assets                                                                                         |   | (Thousands of dollars) |
| Current assets                                                                                 |   |   |   |   |
| Cash and cash equivalents                                                                      |   | $ | 8,476 |  |   | $ | 406 |  |
| Accounts receivable, net                                                                       |   | 734,780 |  |   | 872,310 |  |
| Affiliate receivables                                                                          |   | 152 |  |   | 984 |  |
| Natural gas and natural gas liquids in storage                                                 |   | 193,339 |  |   | 140,034 |  |
| Commodity imbalances                                                                           |   | 30,904 |  |   | 60,896 |  |
| Materials and supplies                                                                         |   | 59,726 |  |   | 60,912 |  |
| Other current assets                                                                           |   | 38,368 |  |   | 38,703 |  |
| Total current assets                                                                           |   | 1,065,745 |  |   | 1,174,245 |  |
| Property, plant and equipment                                                                  |   |   |  |   |   |  |
| Property, plant and equipment                                                                  |   | 14,930,541 |  |   | 14,854,696 |  |
| Accumulated depreciation and amortization                                                      |   | 2,482,974 |  |   | 2,392,004 |  |
| Net property, plant and equipment                                                              |   | 12,447,567 |  |   | 12,462,692 |  |
| Investments and other assets                                                                   |   |   |  |   |   |  |
| Investments in unconsolidated affiliates                                                       |   | 956,388 |  |   | 958,807 |  |
| Goodwill and intangible assets                                                                 |   | 810,003 |  |   | 812,977 |  |
| Other assets                                                                                   |   | 62,232 |  |   | 60,626 |  |
| Total investments and other assets                                                             |   | 1,828,623 |  |   | 1,832,410 |  |
| Total assets                                                                                   |   | $ | 15,341,935 |  |   | $ | 15,469,347 |  |
| Liabilities and equity                                                                         |   |   |  |   |   |  |
| Current liabilities                                                                            |   |   |  |   |   |  |
| Current maturities of long-term debt                                                           |   | $ | 407,650 |  |   | $ | 407,650 |  |
| Short-term borrowings                                                                          |   | 1,290,729 |  |   | 1,110,277 |  |
| Accounts payable                                                                               |   | 691,736 |  |   | 862,436 |  |
| Affiliate payables                                                                             |   | 22,685 |  |   | 68,233 |  |
| Commodity imbalances                                                                           |   | 114,542 |  |   | 142,646 |  |
| Accrued interest                                                                               |   | 72,240 |  |   | 87,130 |  |
| Other current liabilities                                                                      |   | 94,949 |  |   | 146,004 |  |
| Total current liabilities                                                                      |   | 2,694,531 |  |   | 2,824,376 |  |
| Long-term debt, excluding current maturities                                                   |   | 6,290,952 |  |   | 6,291,307 |  |
| Deferred credits and other liabilities                                                         |   | 193,797 |  |   | 175,844 |  |
| Commitments and contingencies                                                                  |   |   |   |   |
| Equity                                                                                         |   |   |  |   |   |  |
| ONEOK Partners, L.P. partners’ equity:                                                   |   |   |  |   |   |  |
| General partner                                                                                |   | 224,761 |  |   | 226,039 |  |
| Common units: 212,837,980 units issued and outstanding atMarch 31, 2017, and December 31, 2016 |   | 4,774,781 |  |   | 4,821,397 |  |
| Class B units: 72,988,252 units issued and outstanding atMarch 31, 2017, and December 31, 2016 |   | 1,117,842 |  |   | 1,133,828 |  |
| Accumulated other comprehensive loss                                                           |   | (112,516 | ) |   | (161,526 | ) |
| Total ONEOK Partners, L.P. partners’ equity                                              |   | 6,004,868 |  |   | 6,019,738 |  |
| Noncontrolling interests in consolidated subsidiaries                                          |   | 157,787 |  |   | 158,082 |  |
| Total equity                                                                                   |   | 6,162,655 |  |   | 6,177,820 |  |
| Total liabilities and equity                                                                   |   | $ | 15,341,935 |  |   | $ | 15,469,347 |  |

----

|                                                                                        |
|----------------------------------------------------------------------------------------|
|                                                                                        |  |  |  |  |  |  |  |  |
| ONEOK Partners, L.P. and Subsidiaries                                                  |   |   |   |   |
| CONSOLIDATED STATEMENTS OF CASH FLOWS                                                  |   |   |   |   |
|                                                                                   |   | Three Months Ended |
|                                                                                   |   | March 31, |
| (Unaudited)                                                                            |   | 2017 |   | 2016 |
|                                                                                   |   | (Thousands of dollars) |
| Operating activities                                                                   |   |   |   |   |
| Net income                                                                             |   | $ | 270,026 |  |   | $ | 256,286 |  |
| Adjustments to reconcile net income to net cash provided by operating activities:      |   |   |   |   |
| Depreciation and amortization                                                          |   | 98,626 |  |   | 93,736 |  |
| Equity in net earnings from investments                                                |   | (39,564 | ) |   | (32,914 | ) |
| Distributions received from unconsolidated affiliates                                  |   | 39,520 |  |   | 34,789 |  |
| Deferred income taxes                                                                  |   | 3,035 |  |   | 2,254 |  |
| Allowance for equity funds used during construction                                    |   | (13 | ) |   | (208 | ) |
| (Gain) loss on sale of assets                                                          |   | 7 |  |   | (4,145 | ) |
| Changes in assets and liabilities:                                                     |   |   |  |   |   |  |
| Accounts receivable                                                                    |   | 137,530 |  |   | 68,618 |  |
| Affiliate receivables                                                                  |   | 832 |  |   | 4,406 |  |
| Natural gas and natural gas liquids in storage                                         |   | (53,305 | ) |   | (27,991 | ) |
| Accounts payable                                                                       |   | (122,090 | ) |   | (62,401 | ) |
| Affiliate payables                                                                     |   | (45,548 | ) |   | (7,067 | ) |
| Commodity imbalances, net                                                              |   | 1,888 |  |   | 2,968 |  |
| Accrued interest                                                                       |   | (14,890 | ) |   | (15,897 | ) |
| Risk-management assets and liabilities                                                 |   | 45,100 |  |   | (24,691 | ) |
| Other assets and liabilities, net                                                      |   | (40,848 | ) |   | (21,490 | ) |
| Cash provided by operating activities                                                  |   | 280,306 |  |   | 266,253 |  |
| Investing activities                                                                   |   |   |  |   |   |  |
| Capital expenditures (less allowance for equity funds used during construction)        |   | (112,584 | ) |   | (195,896 | ) |
| Contributions to unconsolidated affiliates                                             |   | (4,422 | ) |   | (158 | ) |
| Distributions received from unconsolidated affiliates in excess of cumulative earnings |   | 7,400 |  |   | 11,764 |  |
| Proceeds from sale of assets                                                           |   | 161 |  |   | 14,797 |  |
| Cash used in investing activities                                                      |   | (109,445 | ) |   | (169,493 | ) |
| Financing activities                                                                   |   |   |  |   |   |  |
| Cash distributions:                                                                    |   |   |  |   |   |  |
| General and limited partners                                                           |   | (333,001 | ) |   | (333,001 | ) |
| Noncontrolling interests                                                               |   | (1,200 | ) |   | (2,500 | ) |
| Borrowing (repayment) of short-term borrowings, net                                    |   | 180,452 |  |   | (101,773 | ) |
| Issuance of long-term debt, net of discounts                                           |   | — |  |   | 1,000,000 |  |
| Debt financing costs                                                                   |   | — |  |   | (2,770 | ) |
| Repayment of long-term debt                                                            |   | (1,912 | ) |   | (651,913 | ) |
| Other                                                                                  |   | (7,130 | ) |   | — |  |
| Cash used in financing activities                                                      |   | (162,791 | ) |   | (91,957 | ) |
| Change in cash and cash equivalents                                                    |   | 8,070 |  |   | 4,803 |  |
| Cash and cash equivalents at beginning of period                                       |   | 406 |  |   | 5,079 |  |
| Cash and cash equivalents at end of period                                             |   | $ | 8,476 |  |   | $ | 9,882 |  |

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|                                                                                                 |  |  |  |  |  |  |  |  |
| ONEOK Partners, L.P. and Subsidiaries                                                           |   |   |   |   |
| INFORMATION AT A GLANCE                                                                         |   |   |   |   |
|                                                                                            |   | Three Months Ended |
|                                                                                            |   | March 31, |
| (Unaudited)                                                                                     |   | 2017 |   | 2016 |
|                                                                                            |   | (Millions of dollars, except as noted) |
| Natural Gas Liquids                                                                             |   |   |   |   |
| Operating costs                                                                                 |   | $ | 78.7 |  |   | $ | 73.2 |  |
| Depreciation and amortization                                                                   |   | $ | 41.1 |  |   | $ | 40.7 |  |
| Equity in net earnings from investments                                                         |   | $ | 13.7 |  |   | $ | 13.3 |  |
| Adjusted EBITDA                                                                                 |   | $ | 278.2 |  |   | $ | 270.2 |  |
| NGLs transported-gathering lines (MBbl/d) (a)                                                   |   | 764 |  |   | 751 |  |
| NGLs fractionated (MBbl/d) (b)                                                                  |   | 574 |  |   | 550 |  |
| NGLs transported-distribution lines (MBbl/d) (a)                                                |   | 550 |  |   | 474 |  |
| Average Conway-to-Mont Belvieu OPIS price differential -ethane in ethane/propane mix ($/gallon) |   | $ | 0.03 |  |   | $ | 0.03 |  |
| Capital expenditures                                                                            |   | $ | 20.5 |  |   | $ | 34.2 |  |
| (a) - Includes volumes for consolidated entities only.                                          |   |   |   |   |
| (b) - Includes volumes at company-owned and third-party facilities.                             |   |   |   |   |
|                                                                                            |   |   |   |   |
| Natural Gas Gathering and Processing                                                            |   |   |   |   |
| Operating costs                                                                                 |   | $ | 71.8 |  |   | $ | 69.6 |  |
| Depreciation and amortization                                                                   |   | $ | 45.0 |  |   | $ | 41.9 |  |
| Equity in net earnings from investments                                                         |   | $ | 2.6 |  |   | $ | 2.8 |  |
| Adjusted EBITDA                                                                                 |   | $ | 104.0 |  |   | $ | 100.0 |  |
| Natural gas gathered (BBtu/d) (a)                                                               |   | 1,985 |  |   | 2,128 |  |
| Natural gas processed (BBtu/d) (a) (b)                                                          |   | 1,863 |  |   | 1,948 |  |
| NGL sales (MBbl/d) (a)                                                                          |   | 172 |  |   | 155 |  |
| Residue natural gas sales (BBtu/d) (a)                                                          |   | 793 |  |   | 941 |  |
| Realized composite NGL net sales price ($/gallon) (a) (c) (d)                                   |   | $ | 0.19 |  |   | $ | 0.20 |  |
| Realized condensate net sales price ($/Bbl) (a) (c) (e)                                         |   | $ | 32.32 |  |   | $ | 33.72 |  |
| Realized residue natural gas net sales price ($/MMBtu) (a) (c) (e)                              |   | $ | 2.38 |  |   | $ | 2.62 |  |
| Average fee rate ($/MMBtu) (a)                                                             |   | $ | 0.83 |  |   | $ | 0.68 |  |
| Capital expenditures                                                                            |   | $ | 63.2 |  |   | $ | 141.5 |  |
| (a) - Includes volumes for consolidated entities only.                                          |   |   |   |   |
| (b) - Includes volumes at company-owned and third-party facilities.                             |   |   |   |   |
| (c) - Includes the impact of hedging activities on our equity volumes.                          |   |   |   |   |
| (d) - Net of transportation and fractionation costs.                                            |   |   |   |   |
| (e) - Net of transportation costs.                                                              |   |   |   |   |
|                                                                                            |   |   |   |   |
| Natural Gas Pipelines                                                                           |   |   |   |   |
| Operating costs                                                                                 |   | $ | 31.8 |  |   | $ | 27.5 |  |
| Depreciation and amortization                                                                   |   | $ | 12.5 |  |   | $ | 11.2 |  |
| Equity in net earnings from investments                                                         |   | $ | 23.2 |  |   | $ | 16.8 |  |
| Adjusted EBITDA                                                                                 |   | $ | 83.0 |  |   | $ | 74.3 |  |
| Natural gas transportation capacity contracted (MDth/d) (a)                                     |   | 6,757 |  |   | 6,156 |  |
| Transportation capacity subscribed (a)                                                          |   | 97 | % |   | 93 | % |
| Capital expenditures                                                                            |   | $ | 25.0 |  |   | $ | 17.9 |  |
| (a) - Includes volumes for consolidated entities only.                                          |   |   |   |   |

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|                                                                             |  |  |  |  |  |  |  |  |
| ONEOK Partners, L.P. and Subsidiaries                                       |   |   |   |   |
| RECONCILIATION OF NON-GAAP FINANCIAL MEASURES                               |   |   |
|                                                                        |   | Three Months Ended |
|                                                                        |   | March 31, |
| (Unaudited)                                                                 |   | 2017 |   | 2016 |
|                                                                        |   | (Thousands of dollars, except per unit amounts) |
| Reconciliation of Net Income to Adjusted EBITDA and Distributable Cash Flow |
| Net income                                                                  |   | $ | 270,026 |  |   | $ | 256,286 |  |
| Interest expense, net of capitalized interest                               |   | 90,707 |  |   | 92,555 |  |
| Depreciation and amortization                                               |   | 98,626 |  |   | 93,736 |  |
| Income taxes                                                                |   | 3,837 |  |   | 2,028 |  |
| Other noncash items and equity AFUDC                                        |   | 958 |  |   | (19 | ) |
| Adjusted EBITDA                                                             |   | 464,154 |  |   | 444,586 |  |
| Interest expense, net of capitalized interest                               |   | (90,707 | ) |   | (92,555 | ) |
| Maintenance capital                                                         |   | (24,236 | ) |   | (22,143 | ) |
| Equity in net earnings from investments                                     |   | (39,564 | ) |   | (32,914 | ) |
| Distributions received from unconsolidated affiliates                       |   | 46,920 |  |   | 46,553 |  |
| Other                                                                       |   | (1,203 | ) |   | 4,034 |  |
| Distributable cash flow                                                     |   | $ | 355,364 |  |   | $ | 347,561 |  |
| Distributions to general partner                                            |   | (107,198 | ) |   | (107,198 | ) |
| Distributable cash flow to limited partners                                 |   | $ | 248,166 |  |   | $ | 240,363 |  |
| Distributions declared per limited partner unit                             |   | $ | 0.79 |  |   | $ | 0.79 |  |
| Distribution coverage ratio                                                 |   | 1.10 |  |   | 1.06 |  |
| Number of units used in computation (thousands)                             |   | 285,826 |  |   | 285,826 |  |