----

|                |
|----------------|
|                |  |  |  |
| August 4, 2015 |   | Analyst Contact: | T.D. Eureste918-588-7167 |
|           |   | Media Contact: | Brad Borror918-588-7582 |

|         |                                                                                                 |
|---------|-------------------------------------------------------------------------------------------------|
| • | Natural gas liquids gathered and fractionated volumes increased 51 and 7 percent, respectively; |

|         |                                                                                       |
|---------|---------------------------------------------------------------------------------------|
| • | Natural gas gathered and processed volumes increased 17 and 16 percent, respectively; |

|         |                                                                                         |
|---------|-----------------------------------------------------------------------------------------|
| • | Adjusted EBITDA increased 7 percent, all compared with second-quarter 2014 results; and |

|         |                                                                                                                              |
|---------|------------------------------------------------------------------------------------------------------------------------------|
| • | Operating income and equity in net earnings from investments increased 32 percent, compared with first-quarter 2015 results. |

|                                                                                                                                                                                                                                                                        |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|                                                                                                                                                                                                                                                                        |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|                                                                                                                                                                                                                                                                   | Three Months Ended |   | Six Months Ended |
|                                                                                                                                                                                                                                                                   | June 30, |   | June 30, |
|                                                                                                                                                                                                                                                                   | 2015 |   | 2014 |   | 2015 |   | 2014 |
|                                                                                                                                                                                                                                                                   | (Millions of dollars, except per unit and coverage ratio amounts) |
|                                                                                                                                                                                                                                                                   |   |   |   |   |   |   |   |
| Net income attributable to ONEOK Partners                                                                                                                                                                                                                              | $ | 209.8 |  |   | $ | 214.4 |  |   | $ | 355.4 |  |   | $ | 479.8 |  |
| Net income per limited partner unit                                                                                                                                                                                                                                    | $ | 0.44 |  |   | $ | 0.54 |  |   | $ | 0.65 |  |   | $ | 1.35 |  |
| Adjusted EBITDA (a)                                                                                                                                                                                                                                                    | $ | 387.3 |  |   | $ | 360.9 |  |   | $ | 711.6 |  |   | $ | 754.6 |  |
| DCF (a)                                                                                                                                                                                                                                                                | $ | 276.9 |  |   | $ | 272.0 |  |   | $ | 494.1 |  |   | $ | 570.2 |  |
| Cash distribution coverage ratio (a)                                                                                                                                                                                                                                   | 0.88 |  |   | 1.02 |  |   | 0.74 |  |   | 1.14 |  |
| (a) Adjusted earnings before interest, taxes, depreciation and amortization (adjusted EBITDA); distributable cash flow (DCF); and cash distribution coverage ratio are non-GAAP measures. Reconciliations to relevant GAAP measures are attached to this news release. |

----

|                                         |
|-----------------------------------------|
|                                         |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|                                    | Three Months Ended |   | Six Months Ended |
|                                    | June 30, |   | June 30, |
|                                    | 2015 |   | 2014 |   | 2015 |   | 2014 |
|                                    | (Millions of dollars) |
|                                    |   |   |   |   |   |   |   |
| Operating income                        | $ | 271.7 |  |   | $ | 262.2 |  |   | $ | 468.6 |  |   | $ | 555.0 |  |
| Operating costs                         | $ | 166.6 |  |   | $ | 160.6 |  |   | $ | 344.8 |  |   | $ | 310.8 |  |
| Depreciation and amortization           | $ | 86.2 |  |   | $ | 71.4 |  |   | $ | 172.0 |  |   | $ | 138.2 |  |
| Equity in net earnings from investments | $ | 30.0 |  |   | $ | 25.4 |  |   | $ | 61.0 |  |   | $ | 59.1 |  |
| Capital expenditures                    | $ | 285.4 |  |   | $ | 389.4 |  |   | $ | 628.4 |  |   | $ | 792.4 |  |

|         |                                                                                                                                                                                                                           |
|---------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Higher NGL exchange-services volumes from recently connected natural gas processing plants in the Williston Basin, Powder River Basin and Mid-Continent regions, and additional revenues from minimum volume obligations; |

|         |                                                                                                              |
|---------|--------------------------------------------------------------------------------------------------------------|
| • | Higher NGL transportation margins, primarily from the acquisition of the West Texas LPG pipeline system; and |

|         |                                                                                                                                                                                                                  |
|---------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Higher margins due to changes in contract mix and higher natural gas volumes gathered, processed and sold, and higher NGL volumes sold, in the natural gas gathering and processing segment; offset partially by |

|         |                                                            |
|---------|------------------------------------------------------------|
| • | Lower net realized NGL, natural gas and condensate prices. |

----

|         |                                                                                                                                                                                                                                                |
|---------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Reaffirming its 2015 adjusted EBITDA guidance range of $1.51 billion to $1.73 billion; its DCF guidance range of $1.08 billion to $1.26 billion; and its net income guidance range of $845 million to $1.01 billion provided on Feb. 23, 2015; |

|         |                                                                                                                                                                                                                                                                                                                                                                                                   |
|---------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Announcing in July the WesTex Transmission Pipeline expansion, an investment of $70 million to $100 million to construct two compressor stations and upgrade three existing compressor stations. The expansion project will complement the Roadrunner Gas Transmission pipeline joint venture and provide markets in Mexico access to upstream supply basins in West Texas and the Mid-Continent; |

|         |                                                                                                                                                               |
|---------|---------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Adding two new third-party natural gas processing plant connections to the partnership’s NGL system, one each in the Williston Basin and Mid-Continent; |

|         |                                                                                                                                                               |
|---------|---------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Adding two new compressor stations totaling 28,000 horsepower to the partnership’s natural gas gathering system, both in McKenzie County, North Dakota; |

|         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
|---------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Completing the sale of approximately 5.5 million common units through the partnership’s at-the-market (ATM) equity program in the second quarter. The net proceeds, including ONEOK’s contribution to maintain its 2 percent general partner interest, were approximately $208.1 million, which resulted in ONEOK’s aggregate ownership interest in ONEOK Partners decreasing to 36.8 percent at June 30, 2015, from 37.6 percent at March 31, 2015. As of  June 30, 2015, the partnership had approximately $238 million of common units available to issue through its $650 million ATM program; and |

|         |                                                                                                                                                                                       |
|---------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Declaring in July 2015 a second-quarter 2015 distribution of 79 cents per unit, or $3.16 per unit on an annualized basis, a 4 percent increase compared with the second quarter 2014. |

----

|                                         |
|-----------------------------------------|
|                                         |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|                                    | Three Months Ended |   | Six Months Ended |
|                                    | June 30, |   | June 30, |
|                                    | 2015 |   | 2014 |   | 2015 |   | 2014 |
|                                    | (Millions of dollars) |
|                                    |   |   |   |   |   |   |   |
| Operating income                        | $ | 196.5 |  |   | $ | 159.0 |  |   | $ | 342.1 |  |   | $ | 335.7 |  |
| Operating costs                         | $ | 77.4 |  |   | $ | 76.1 |  |   | $ | 159.7 |  |   | $ | 141.2 |  |
| Depreciation and amortization           | $ | 39.4 |  |   | $ | 31.1 |  |   | $ | 78.7 |  |   | $ | 58.2 |  |
| Equity in net earnings from investments | $ | 9.7 |  |   | $ | 4.5 |  |   | $ | 16.7 |  |   | $ | 9.2 |  |

|         |                                                                                                                                                                                                                                                                                                       |
|---------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | A $57.2 million increase in exchange-services margins, resulting primarily from increased volumes from recently connected natural gas processing plants in the Williston Basin, Powder River Basin and Mid-Continent regions, and higher revenues from customers with minimum volume obligations; and |

|         |                                                                                                                                                                        |
|---------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | A $22.2 million increase in transportation margins, primarily from new Permian Basin NGL volumes from the acquired West Texas LPG pipeline system; offset partially by |

|         |                                                                                                                                                                    |
|---------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | A $19.1 million decrease related to lower isomerization volumes, resulting from narrower NGL product price differentials between normal butane and iso-butane; and |

|         |                                                                                                                                                                                                                                                                                                                                       |
|---------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | A $9.7 million decrease in optimization and marketing margins, which resulted from a $14.3 million decrease due primarily to narrower realized NGL product price differentials and a $1.0 million decrease in marketing margins, offset partially by a $5.7 million increase due primarily to wider NGL location price differentials. |

----

|         |                                                                                                                                                                                                                                                                                                       |
|---------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | A $122.2 million increase in exchange-services margins, resulting primarily from increased volumes from recently connected natural gas processing plants, higher fees for exchange-services activities resulting from contract negotiations, and higher revenues from minimum volume obligations; and |

|         |                                                                                                                                                       |
|---------|-------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | A $41.0 million increase in transportation margins, primarily from higher volumes on the acquired West Texas LPG pipeline system; offset partially by |

|         |                                                                                                                                                                  |
|---------|------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | An $83.0 million decrease in optimization and marketing margins related primarily to the increased demand for propane experienced during the first quarter 2014; |

|         |                                                                      |
|---------|----------------------------------------------------------------------|
| • | A $20.4 million decrease related to lower isomerization volumes; and |

|         |                                                                                       |
|---------|---------------------------------------------------------------------------------------|
| • | A $10.5 million decrease resulting from ethane rejection, which impacted NGL volumes. |

|                                         |
|-----------------------------------------|
|                                         |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|                                    | Three Months Ended |   | Six Months Ended |
|                                    | June 30, |   | June 30, |
|                                    | 2015 |   | 2014 |   | 2015 |   | 2014 |
|                                    | (Millions of dollars) |
|                                    |   |   |   |   |   |   |   |
| Operating income                        | $ | 38.1 |  |   | $ | 37.3 |  |   | $ | 69.2 |  |   | $ | 92.4 |  |
| Operating costs                         | $ | 25.2 |  |   | $ | 27.3 |  |   | $ | 52.4 |  |   | $ | 54.7 |  |
| Depreciation and amortization           | $ | 10.8 |  |   | $ | 10.9 |  |   | $ | 21.6 |  |   | $ | 21.7 |  |
| Equity in net earnings from investments | $ | 15.4 |  |   | $ | 15.9 |  |   | $ | 35.1 |  |   | $ | 39.3 |  |

----

|         |                                                                                                                                                                                                              |
|---------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | A $13.0 million decrease from lower short-term natural gas storage services, due primarily to increased weather-related seasonal demand associated with severely cold weather in the first quarter 2014; and |

|         |                                                                                                                                                  |
|---------|--------------------------------------------------------------------------------------------------------------------------------------------------|
| • | A $9.1 million decrease from lower net retained fuel due to lower natural gas prices and lower natural gas volumes retained; offset partially by |

|         |                                                                                                                                                                            |
|---------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | A $4.6 million increase due to higher transportation revenues, primarily from increased rates on intrastate pipelines and higher rates at Viking Gas Transmission Company. |

|                                         |
|-----------------------------------------|
|                                         |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|                                    | Three Months Ended |   | Six Months Ended |
|                                    | June 30, |   | June 30, |
|                                    | 2015 |   | 2014 |   | 2015 |   | 2014 |
|                                    | (Millions of dollars) |
|                                    |   |   |   |   |   |   |   |
| Operating income                        | $ | 37.8 |  |   | $ | 66.1 |  |   | $ | 57.5 |  |   | $ | 126.0 |  |
| Operating costs                         | $ | 63.5 |  |   | $ | 59.4 |  |   | $ | 132.8 |  |   | $ | 124.2 |  |
| Depreciation and amortization           | $ | 36.0 |  |   | $ | 29.4 |  |   | $ | 71.7 |  |   | $ | 58.3 |  |
| Equity in net earnings from investments | $ | 4.9 |  |   | $ | 5.1 |  |   | $ | 9.2 |  |   | $ | 10.6 |  |

----

|         |                                                                                                                          |
|---------|--------------------------------------------------------------------------------------------------------------------------|
| • | A $45.6 million decrease due primarily to lower net realized NGL, natural gas and condensate prices; offset partially by |

|         |                                                                                                                                                                                                                                                                 |
|---------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | A $16.3 million increase due primarily to natural gas volume growth in the Williston Basin and Cana-Woodford Shale, resulting in higher natural gas volumes gathered, compressed, processed, transported and sold, higher NGL volumes sold and higher fees; and |

|         |                                                                                                |
|---------|------------------------------------------------------------------------------------------------|
| • | An $11.5 million increase due primarily to changes in contract mix resulting from higher fees. |

|         |                                                                                                                          |
|---------|--------------------------------------------------------------------------------------------------------------------------|
| • | A $99.4 million decrease due primarily to lower net realized NGL, natural gas and condensate prices; offset partially by |

|         |                                                                                                                                                                                                                                                                 |
|---------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | A $33.3 million increase due primarily to natural gas volume growth in the Williston Basin and Cana-Woodford Shale, resulting in higher natural gas volumes gathered, compressed, processed, transported and sold, higher NGL volumes sold and higher fees; and |

|         |                                                                                               |
|---------|-----------------------------------------------------------------------------------------------|
| • | A $19.4 million increase due primarily to changes in contract mix resulting from higher fees. |

|                                                        |
|--------------------------------------------------------|
|                                                        |  |  |  |  |  |  |  |  |  |  |  |
|                                                   | Three Months Ended |   | Six Months Ended |
|                                                   | June 30, |   | June 30, |
| Equity-Volume Information (a)                          | 2015 |   | 2014 |   | 2015 |   | 2014 |
|                                                   |   |   |   |   |   |   |   |
| NGL sales (MBbl/d)                                     | 21.1 |  |   | 15.9 |  |   | 19.0 |  |   | 16.8 |  |
| Condensate sales (MBbl/d)                              | 3.1 |  |   | 3.1 |  |   | 3.1 |  |   | 3.3 |  |
| Residue natural gas sales (BBtu/d)                     | 155.5 |  |   | 105.3 |  |   | 144.3 |  |   | 96.9 |  |
| (a) - Includes volumes for consolidated entities only. |   |   |   |   |   |   |   |

----

|                                                        |
|--------------------------------------------------------|
|                                                        |  |  |  |  |  |  |  |  |  |
|                                                   | Six Months Ending December 31, 2015 |
|                                                   | VolumesHedged |   | Average Price |   | PercentageHedged |
| NGLs - excluding ethane (MBbl/d) - Conway/Mont Belvieu | 14.1 |  |   | $ | 0.66 |  | / gallon |   | 72% |
| Condensate (MBbl/d) - WTI-NYMEX                        | 2.0 |  |   | $ | 55.14 |  | / Bbl |   | 68% |
| Natural gas (BBtu/d) - NYMEX and basis                 | 123.0 |  |   | $ | 3.88 |  | / MMBtu |   | 88% |

|                                                        |
|--------------------------------------------------------|
|                                                        |  |  |  |  |  |  |  |  |  |
|                                                   | Year Ending December 31, 2016 |
|                                                   | VolumesHedged |   | Average Price |   | PercentageHedged |
| NGLs - excluding ethane (MBbl/d) - Conway/Mont Belvieu | 3.9 |  |   | $ | 0.58 |  | / gallon |   | 18% |
| Condensate (MBbl/d) - WTI-NYMEX                        | 1.5 |  |   | $ | 62.65 |  | / Bbl |   | 45% |
| Natural gas (BBtu/d) - NYMEX and basis                 | 107.9 |  |   | $ | 3.10 |  | / MMBtu |   | 69% |

|         |                                                                                                                                        |
|---------|----------------------------------------------------------------------------------------------------------------------------------------|
| • | A 10-cent-per-MMBtu change in the price of residue natural gas would change 12-month forward net margin by approximately $5.3 million; |

|         |                                                                                                                                       |
|---------|---------------------------------------------------------------------------------------------------------------------------------------|
| • | A 1-cent-per-gallon change in the composite price of NGLs would change 12-month forward net margin by approximately $4.0 million; and |

|         |                                                                                                                             |
|---------|-----------------------------------------------------------------------------------------------------------------------------|
| • | A $1.00-per-barrel change in the price of crude oil would change 12-month forward net margin by approximately $1.7 million. |

----

|                                                         |
|---------------------------------------------------------|
|                                                         |  |  |  |  |
| Completed Projects                                      | Location | Capacity | Approximate Costs (a) | Completion Date |
|                                                    |   |   | (In millions) |   |
| Ethane/Propane Splitter                                 | Texas Gulf Coast | 40 MBbl/d | $46 | March 2014 |
| Sterling III Pipeline and reconfigure Sterling I and II | Mid-Continent Region | 193 MBbl/d | $808 | March 2014 |
| Bakken NGL Pipeline expansion - Phase I                 | Rocky Mountain Region | 75 MBbl/d | $75-$90 | September 2014 |
| Niobrara NGL Lateral                                    | Powder River Basin | 90 miles | $70-$75 | September 2014 |
| West Texas LPG pipeline system (b)                      | Permian Basin | 2,600 miles | $800 | November 2014 |
| MB-3 Fractionator                                       | Texas Gulf Coast | 75 MBbl/d | $520-$540 | December 2014 |
| NGL Pipeline and Hutchinson Fractionator infrastructure | Mid-Continent Region | 95 miles | $110-$125 | April 2015 |

|                                          |
|------------------------------------------|
|                                          |  |  |  |  |
| Projects in Progress                     | Location | Capacity | Approximate Costs (a) | Expected Completion Date |
|                                     |   |   | (In millions) |   |
| Bakken NGL Pipeline expansion - Phase II | Rocky Mountain Region | 25 MBbl/d | $100 | Second quarter 2016 |
| Bear Creek NGL infrastructure            | Williston Basin | 40 miles | $35-$45 | Third quarter 2016 |
| Bronco NGL infrastructure                | Powder River Basin | 65 miles | $45-$60 | Suspended |
| Demicks Lake NGL infrastructure          | Williston Basin | 12 miles | $10-$15 | Suspended |

----

|                                                              |
|--------------------------------------------------------------|
|                                                              |  |  |  |  |
| Projects in Progress                                         | Location | Capacity | Approximate Costs (a) | Expected Completion Date |
|                                                         |   |   | (In millions) |   |
| WesTex Transmission Pipeline Expansion                       | Permian Basin | 260 MMcf/d | $70-$100 | First quarter 2017 |
| Roadrunner Gas Transmission Pipeline - Phases I, II, III (b) | Permian Basin | 640 MMcf/d | $450-$500 | Various |
| -Phase I                                                     | Permian Basin | 170 MMcf/d | $200-$220 | First quarter 2016 |
| -Phase II                                                    | Permian Basin | 400 MMcf/d | $220-$240 | First quarter 2017 |
| -Phase III                                                   | Permian Basin | 70 MMcf/d | $30-$40 | 2019 |

|                                                      |
|------------------------------------------------------|
|                                                      |  |  |  |  |
| Completed Projects                                   | Location | Capacity | ApproximateCosts (a) | Completion Date |
|                                                 |   |   | (In millions) |   |
| Rocky Mountain Region                                |   |   |
| Garden Creek II processing plant and infrastructure  | Williston Basin | 100 MMcf/d | $300-$310 | August 2014 |
| Garden Creek III processing plant and infrastructure | Williston Basin | 100 MMcf/d | $300-$310 | October 2014 |
| Mid-Continent Region                                 |   |   |   |   |
| Canadian Valley processing plant and infrastructure  | Cana-Woodford Shale | 200 MMcf/d | $255 | March 2014 |

|                                                    |
|----------------------------------------------------|
|                                                    |  |  |  |  |
| Projects in Progress                               | Location | Capacity | ApproximateCosts (a) | ExpectedCompletion Date |
|                                               |   |   | (In millions) |   |
| Rocky Mountain Region                              |   |   |
| Sage Creek infrastructure                          | Powder River Basin | Various | $50 | Fourth quarter 2015 |
| Natural gas compression                            | Williston Basin | 100 MMcf/d | $80-$100 | Fourth quarter 2015 |
| Lonesome Creek processing plant and infrastructure | Williston Basin | 200 MMcf/d | $550-$680 | Fourth quarter 2015 |
| Stateline de-ethanizers                            | Williston Basin | 26 MBbl/d | $60-$80 | Third quarter 2016 |
| Bear Creek processing plant and infrastructure     | Williston Basin | 80 MMcf/d | $230-$330 | Third quarter 2016 |
| Bronco processing plant and infrastructure         | Powder River Basin | 50 MMcf/d | $130-$200 | Suspended |
| Demicks Lake processing plant and infrastructure   | Williston Basin | 200 MMcf/d | $475-$670 | Suspended |
| Mid-Continent Region                               |   |   |   |   |
| Knox processing plant and infrastructure           | SCOOP | 200 MMcf/d | $240-$470 | Suspended |

----

|         |                                                                                                                                                                                                      |
|---------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Adjusted EBITDA is defined as net income adjusted for interest expense, depreciation and amortization, income taxes and allowance for equity funds used during construction and certain other items; |

|         |                                                                                                                                                                                                                                 |
|---------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | DCF is defined as adjusted EBITDA, computed as described above, less interest expense, maintenance capital expenditures and equity earnings from investments, 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 |

|         |                                                                                                                                                                                                   |
|---------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Cash 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 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 us, our general partner, ONEOK Partners GP, and related parties of ONEOK Partners GP; |

|         |                                                                                                                                                                   |
|---------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | the impact of unforeseen changes in interest rates, equity markets, inflation rates, economic recession and other external factors over which we have no control; |

|         |                                                                                                                                                                                                                                                                                |
|---------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | 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 us or the parent of our general partner; |

|         |                                                                                                                                                                                                                                                                                     |
|---------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | the results of administrative proceedings and litigation, regulatory actions, rule changes and receipt of expected clearances involving the any local, state or federal regulatory body, including the FERC, the National Transportation Safety Board, the PHMSA, the EPA and 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 control over financial reporting could emerge or that minor problems could become significant; |

|         |                                                          |
|---------|----------------------------------------------------------|
| • | the impact and outcome of pending and future litigation; |

|         |                                                                                       |
|---------|---------------------------------------------------------------------------------------|
| • | 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 and 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 risk factors listed in the reports we have filed and may file with the SEC, which are incorporated by reference. |

----

|                                                                                                      |
|------------------------------------------------------------------------------------------------------|
|                                                                                                      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| ONEOK Partners, L.P. and Subsidiaries                                                                |   |   |   |   |   |   |   |
| CONSOLIDATED STATEMENTS OF INCOME                                                                    |   |   |   |   |   |   |   |
|                                                                                                 | Three Months Ended |   | Six Months Ended |
|                                                                                                 | June 30, |   | June 30, |
| (Unaudited)                                                                                          | 2015 |   | 2014 |   | 2015 |   | 2014 |
|                                                                                                 | (Thousands of dollars, except per unit amounts) |
|                                                                                                 |   |   |   |   |   |   |   |
| Revenues                                                                                             |   |   |   |   |   |   |   |
| Commodity sales                                                                                      | $ | 1,722,254 |  |   | $ | 2,715,109 |  |   | $ | 3,157,970 |  |   | $ | 5,521,838 |  |
| Services                                                                                             | 405,253 |  |   | 350,626 |  |   | 774,296 |  |   | 706,200 |  |
| Total revenues                                                                                       | 2,127,507 |  |   | 3,065,735 |  |   | 3,932,266 |  |   | 6,228,038 |  |
| Cost of sales and fuel                                                                               | 1,603,093 |  |   | 2,571,402 |  |   | 2,946,957 |  |   | 5,224,071 |  |
| Net margin                                                                                           | 524,414 |  |   | 494,333 |  |   | 985,309 |  |   | 1,003,967 |  |
| Operating expenses                                                                                   |   |  |   |   |  |   |   |  |   |   |  |
| Operations and maintenance                                                                           | 143,131 |  |   | 142,664 |  |   | 298,252 |  |   | 273,182 |  |
| Depreciation and amortization                                                                        | 86,199 |  |   | 71,447 |  |   | 172,046 |  |   | 138,182 |  |
| General taxes                                                                                        | 23,481 |  |   | 17,981 |  |   | 46,519 |  |   | 37,646 |  |
| Total operating expenses                                                                             | 252,811 |  |   | 232,092 |  |   | 516,817 |  |   | 449,010 |  |
| Gain (loss) on sale of assets                                                                        | 122 |  |   | (16 | ) |   | 116 |  |   | (1 | ) |
| Operating income                                                                                     | 271,725 |  |   | 262,225 |  |   | 468,608 |  |   | 554,956 |  |
| Equity in net earnings from investments                                                              | 30,040 |  |   | 25,435 |  |   | 60,961 |  |   | 59,094 |  |
| Allowance for equity funds used during construction                                                  | 742 |  |   | 1,253 |  |   | 1,541 |  |   | 12,224 |  |
| Other income                                                                                         | 24 |  |   | 3,189 |  |   | 2,547 |  |   | 4,522 |  |
| Other expense                                                                                        | (1,953 | ) |   | (1,389 | ) |   | (2,578 | ) |   | (2,158 | ) |
| Interest expense (net of capitalized interest of $9,927, $11,375, $17,157 and $27,143, respectively) | (86,492 | ) |   | (73,008 | ) |   | (167,201 | ) |   | (141,284 | ) |
| Income before income taxes                                                                           | 214,086 |  |   | 217,705 |  |   | 363,878 |  |   | 487,354 |  |
| Income taxes                                                                                         | (2,476 | ) |   | (3,194 | ) |   | (5,236 | ) |   | (7,375 | ) |
| Net income                                                                                           | 211,610 |  |   | 214,511 |  |   | 358,642 |  |   | 479,979 |  |
| Less:  Net income attributable to noncontrolling interests                                           | 1,840 |  |   | 77 |  |   | 3,278 |  |   | 153 |  |
| Net income attributable to ONEOK Partners, L.P.                                                      | $ | 209,770 |  |   | $ | 214,434 |  |   | $ | 355,364 |  |   | $ | 479,826 |  |
|                                                                                                 |   |   |   |   |   |   |   |
| Limited partners’ interest in net income:                                                      |   |  |   |   |  |   |   |  |   |   |  |
| Net income attributable to ONEOK Partners, L.P.                                                      | $ | 209,770 |  |   | $ | 214,434 |  |   | $ | 355,364 |  |   | $ | 479,826 |  |
| General partner’s interest in net income                                                       | (95,989 | ) |   | (84,669 | ) |   | (188,790 | ) |   | (161,901 | ) |
| Limited partners’ interest in net income                                                       | $ | 113,781 |  |   | $ | 129,765 |  |   | $ | 166,574 |  |   | $ | 317,925 |  |
|                                                                                                 |   |   |   |   |   |   |   |
| Limited partners’ net income per unit, basic and diluted                                       | $ | 0.44 |  |   | $ | 0.54 |  |   | $ | 0.65 |  |   | $ | 1.35 |  |
|                                                                                                 |   |   |   |   |   |   |   |
| Number of units used in computation (thousands)                                                      | 257,179 |  |   | 240,503 |  |   | 255,627 |  |   | 236,361 |  |

----

|                                                                                                                             |
|-----------------------------------------------------------------------------------------------------------------------------|
|                                                                                                                             |  |  |  |  |  |  |  |  |
| ONEOK Partners, L.P. and Subsidiaries                                                                                       |   |   |   |   |
| CONSOLIDATED BALANCE SHEETS                                                                                                 |   |   |   |   |
|                                                                                                                        |   | June 30, |   | December 31, |
| (Unaudited)                                                                                                                 |   | 2015 |   | 2014 |
| Assets                                                                                                                      |   | (Thousands of dollars) |
| Current assets                                                                                                              |   |   |   |   |
| Cash and cash equivalents                                                                                                   |   | $ | 53,125 |  |   | $ | 42,530 |  |
| Accounts receivable, net                                                                                                    |   | 683,674 |  |   | 735,830 |  |
| Affiliate receivables                                                                                                       |   | 1,790 |  |   | 8,553 |  |
| Natural gas and natural gas liquids in storage                                                                              |   | 150,137 |  |   | 134,134 |  |
| Commodity imbalances                                                                                                        |   | 31,246 |  |   | 64,788 |  |
| Materials and supplies                                                                                                      |   | 60,505 |  |   | 55,833 |  |
| Other current assets                                                                                                        |   | 56,811 |  |   | 44,385 |  |
| Total current assets                                                                                                        |   | 1,037,288 |  |   | 1,086,053 |  |
|                                                                                                                        |   |   |   |   |
| Property, plant and equipment                                                                                               |   |   |  |   |   |  |
| Property, plant and equipment                                                                                               |   | 13,949,876 |  |   | 13,377,617 |  |
| Accumulated depreciation and amortization                                                                                   |   | 1,995,905 |  |   | 1,842,084 |  |
| Net property, plant and equipment                                                                                           |   | 11,953,971 |  |   | 11,535,533 |  |
|                                                                                                                        |   |   |   |   |
| Investments and other assets                                                                                                |   |   |  |   |   |  |
| Investments in unconsolidated affiliates                                                                                    |   | 1,146,407 |  |   | 1,132,653 |  |
| Goodwill and intangible assets                                                                                              |   | 830,827 |  |   | 822,358 |  |
| Other assets                                                                                                                |   | 28,160 |  |   | 23,803 |  |
| Total investments and other assets                                                                                          |   | 2,005,394 |  |   | 1,978,814 |  |
| Total assets                                                                                                                |   | $ | 14,996,653 |  |   | $ | 14,600,400 |  |
|                                                                                                                        |   |   |   |   |
| Liabilities and equity                                                                                                      |   |   |  |   |   |  |
| Current liabilities                                                                                                         |   |   |  |   |   |  |
| Current maturities of long-term debt                                                                                        |   | $ | 657,650 |  |   | $ | 7,650 |  |
| Notes payable                                                                                                               |   | 870,484 |  |   | 1,055,296 |  |
| Accounts payable                                                                                                            |   | 687,321 |  |   | 874,692 |  |
| Affiliate payables                                                                                                          |   | 28,304 |  |   | 36,106 |  |
| Commodity imbalances                                                                                                        |   | 91,605 |  |   | 104,650 |  |
| Accrued interest                                                                                                            |   | 102,196 |  |   | 91,990 |  |
| Other current liabilities                                                                                                   |   | 127,067 |  |   | 165,672 |  |
| Total current liabilities                                                                                                   |   | 2,564,627 |  |   | 2,336,056 |  |
|                                                                                                                        |   |   |   |   |
| Long-term debt, excluding current maturities                                                                                |   | 6,145,972 |  |   | 6,004,232 |  |
|                                                                                                                        |   |   |   |   |
| Deferred credits and other liabilities                                                                                      |   | 146,320 |  |   | 141,337 |  |
|                                                                                                                        |   |   |   |   |
| Commitments and contingencies                                                                                               |   |   |   |   |
|                                                                                                                        |   |   |   |   |
| Equity                                                                                                                      |   |   |  |   |   |  |
| ONEOK Partners, L.P. partners’ equity:                                                                                |   |   |  |   |   |  |
| General partner                                                                                                             |   | 215,351 |  |   | 211,914 |  |
| Common units: 187,978,848 and 180,826,973 units issued and outstanding at June 30, 2015 and December 31, 2014, respectively |   | 4,562,203 |  |   | 4,456,372 |  |
| Class B units: 72,988,252 units issued and outstanding at June 30, 2015and December 31, 2014                                |   | 1,306,711 |  |   | 1,374,375 |  |
| Accumulated other comprehensive loss                                                                                        |   | (111,090 | ) |   | (91,823 | ) |
| Total ONEOK Partners, L.P. partners’ equity                                                                           |   | 5,973,175 |  |   | 5,950,838 |  |
| Noncontrolling interests in consolidated subsidiaries                                                                       |   | 166,559 |  |   | 167,937 |  |
| Total equity                                                                                                                |   | 6,139,734 |  |   | 6,118,775 |  |
| Total liabilities and equity                                                                                                |   | $ | 14,996,653 |  |   | $ | 14,600,400 |  |

----

|                                                                                        |
|----------------------------------------------------------------------------------------|
|                                                                                        |  |  |  |  |  |  |  |  |
| ONEOK Partners, L.P. and Subsidiaries                                                  |   |   |   |   |
| CONSOLIDATED STATEMENTS OF CASH FLOWS                                                  |   | Six Months Ended |
|                                                                                   |   | June 30, |
| (Unaudited)                                                                            |   | 2015 |   | 2014 |
|                                                                                   |   | (Thousands of dollars) |
| Operating activities                                                                   |   |   |   |   |
| Net income                                                                             |   | $ | 358,642 |  |   | $ | 479,979 |  |
| Adjustments to reconcile net income to net cash provided by operating activities:      |   |   |   |   |
| Depreciation and amortization                                                          |   | 172,046 |  |   | 138,182 |  |
| Allowance for equity funds used during construction                                    |   | (1,541 | ) |   | (12,224 | ) |
| Loss (gain) on sale of assets                                                          |   | (116 | ) |   | 1 |  |
| Deferred income taxes                                                                  |   | 3,983 |  |   | 3,402 |  |
| Equity in net earnings from investments                                                |   | (60,961 | ) |   | (59,094 | ) |
| Distributions received from unconsolidated affiliates                                  |   | 61,969 |  |   | 61,200 |  |
| Changes in assets and liabilities:                                                     |   |   |  |   |   |  |
| Accounts receivable                                                                    |   | 51,062 |  |   | 23,674 |  |
| Affiliate receivables                                                                  |   | 6,763 |  |   | 845 |  |
| Natural gas and natural gas liquids in storage                                         |   | (16,003 | ) |   | (146,830 | ) |
| Accounts payable                                                                       |   | (126,645 | ) |   | 68,045 |  |
| Affiliate payables                                                                     |   | (7,802 | ) |   | (7,678 | ) |
| Commodity imbalances, net                                                              |   | 20,497 |  |   | (18,710 | ) |
| Accrued interest                                                                       |   | 10,206 |  |   | (497 | ) |
| Risk management assets and liabilities                                                 |   | (66,298 | ) |   | (12,200 | ) |
| Other assets and liabilities, net                                                      |   | (25,535 | ) |   | 15,983 |  |
| Cash provided by operating activities                                                  |   | 380,267 |  |   | 534,078 |  |
|                                                                                   |   |   |   |   |
| Investing activities                                                                   |   |   |  |   |   |  |
| Capital expenditures (less allowance for equity funds used during construction)        |   | (628,396 | ) |   | (792,414 | ) |
| Cash paid for acquisitions                                                             |   | — |  |   | (14,000 | ) |
| Contributions to unconsolidated affiliates                                             |   | (33,222 | ) |   | (1,063 | ) |
| Distributions received from unconsolidated affiliates in excess of cumulative earnings |   | 18,814 |  |   | 16,449 |  |
| Proceeds from sale of assets                                                           |   | 691 |  |   | 319 |  |
| Other                                                                                  |   | (12,607 | ) |   | — |  |
| Cash used in investing activities                                                      |   | (654,720 | ) |   | (790,709 | ) |
|                                                                                   |   |   |   |   |
| Financing activities                                                                   |   |   |  |   |   |  |
| Cash distributions:                                                                    |   |   |  |   |   |  |
| General and limited partners                                                           |   | (593,435 | ) |   | (493,049 | ) |
| Noncontrolling interests                                                               |   | (4,694 | ) |   | (181 | ) |
| Borrowing (repayment) of notes payable, net                                            |   | (184,812 | ) |   | — |  |
| Issuance of long-term debt, net of discounts                                           |   | 798,896 |  |   | — |  |
| Debt financing costs                                                                   |   | (7,850 | ) |   | — |  |
| Repayment of long-term debt                                                            |   | (3,825 | ) |   | (3,825 | ) |
| Issuance of common units, net of issuance costs                                        |   | 275,098 |  |   | 878,765 |  |
| Contribution from general partner                                                      |   | 5,670 |  |   | 18,420 |  |
| Cash provided by financing activities                                                  |   | 285,048 |  |   | 400,130 |  |
| Change in cash and cash equivalents                                                    |   | 10,595 |  |   | 143,499 |  |
| Cash and cash equivalents at beginning of period                                       |   | 42,530 |  |   | 134,530 |  |
| Cash and cash equivalents at end of period                                             |   | $ | 53,125 |  |   | $ | 278,029 |  |

----

|                                                                                                 |
|-------------------------------------------------------------------------------------------------|
|                                                                                                 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| ONEOK Partners, L.P. and Subsidiaries                                                           |   |   |   |   |   |   |   |
| INFORMATION AT A GLANCE                                                                         |   |   |   |   |   |   |   |
|                                                                                            | Three Months Ended |   | Six Months Ended |
|                                                                                            | June 30, |   | June 30, |
| (Unaudited)                                                                                     | 2015 |   | 2014 |   | 2015 |   | 2014 |
|                                                                                            | (Millions of dollars, except as noted) |
| Natural Gas Liquids                                                                             |   |   |   |   |   |   |   |
| Net margin                                                                                      | $ | 313.4 |  |   | $ | 266.1 |  |   | $ | 580.6 |  |   | $ | 535.1 |  |
| Operating costs                                                                                 | $ | 77.4 |  |   | $ | 76.0 |  |   | $ | 159.7 |  |   | $ | 141.2 |  |
| Depreciation and amortization                                                                   | $ | 39.4 |  |   | $ | 31.1 |  |   | $ | 78.7 |  |   | $ | 58.2 |  |
| Operating income                                                                                | $ | 196.5 |  |   | $ | 159.0 |  |   | $ | 342.1 |  |   | $ | 335.7 |  |
| Equity in net earnings from investments                                                         | $ | 9.7 |  |   | $ | 4.5 |  |   | $ | 16.7 |  |   | $ | 9.2 |  |
| NGL sales (MBbl/d)                                                                              | 723 |  |   | 603 |  |   | 643 |  |   | 583 |  |
| NGLs transported-gathering lines (MBbl/d) (a)                                                   | 784 |  |   | 520 |  |   | 746 |  |   | 498 |  |
| NGLs fractionated (MBbl/d) (b)                                                                  | 554 |  |   | 520 |  |   | 515 |  |   | 496 |  |
| NGLs transported-distribution lines (MBbl/d) (a)                                                | 420 |  |   | 431 |  |   | 404 |  |   | 430 |  |
| Average Conway-to-Mont Belvieu OPIS price differential -ethane in ethane/propane mix ($/gallon) | $ | 0.02 |  |   | $ | 0.03 |  |   | $ | 0.01 |  |   | $ | 0.08 |  |
| Capital expenditures - growth                                                                   | $ | 48.3 |  |   | $ | 196.9 |  |   | $ | 114.6 |  |   | $ | 457.8 |  |
| Capital expenditures - maintenance                                                              | $ | 10.8 |  |   | $ | 13.8 |  |   | $ | 18.0 |  |   | $ | 25.9 |  |
| (a) - Includes volumes for consolidated entities only.                                          |   |   |   |   |   |   |   |
| (b) - Includes volumes at company-owned and third-party facilities.                             |   |   |   |   |   |   |   |
|                                                                                            |   |   |   |   |   |   |   |
| Natural Gas Pipelines                                                                           |   |   |   |   |   |   |   |
| Net margin                                                                                      | $ | 74.1 |  |   | $ | 75.5 |  |   | $ | 143.2 |  |   | $ | 169.0 |  |
| Operating costs                                                                                 | $ | 25.2 |  |   | $ | 27.3 |  |   | $ | 52.4 |  |   | $ | 54.8 |  |
| Depreciation and amortization                                                                   | $ | 10.8 |  |   | $ | 10.9 |  |   | $ | 21.6 |  |   | $ | 21.7 |  |
| Operating income                                                                                | $ | 38.1 |  |   | $ | 37.3 |  |   | $ | 69.2 |  |   | $ | 92.4 |  |
| Equity in net earnings from investments                                                         | $ | 15.4 |  |   | $ | 15.9 |  |   | $ | 35.1 |  |   | $ | 39.3 |  |
| Natural gas transportation capacity contracted (MDth/d) (a)                                     | 5,714 |  |   | 5,691 |  |   | 5,826 |  |   | 5,778 |  |
| Transportation capacity contracted (a)                                                          | 90 | % |   | 90 | % |   | 92 | % |   | 91 | % |
| Capital expenditures - growth                                                                   | $ | 8.3 |  |   | $ | 2.2 |  |   | $ | 9.2 |  |   | $ | 4.4 |  |
| Capital expenditures - maintenance                                                              | $ | 7.3 |  |   | $ | 6.5 |  |   | $ | 16.0 |  |   | $ | 10.9 |  |
| (a) - Includes volumes for consolidated entities only.                                          |   |   |   |   |   |   |   |
|                                                                                            |   |   |   |   |   |   |   |
| Natural Gas Gathering and Processing                                                            |   |   |   |   |   |   |   |
| Net margin                                                                                      | $ | 137.1 |  |   | $ | 154.9 |  |   | $ | 261.8 |  |   | $ | 308.5 |  |
| Operating costs                                                                                 | $ | 63.5 |  |   | $ | 59.4 |  |   | $ | 132.8 |  |   | $ | 124.2 |  |
| Depreciation and amortization                                                                   | $ | 36.0 |  |   | $ | 29.4 |  |   | $ | 71.7 |  |   | $ | 58.3 |  |
| Operating income                                                                                | $ | 37.8 |  |   | $ | 66.1 |  |   | $ | 57.5 |  |   | $ | 126.0 |  |
| Equity in net earnings from investments                                                         | $ | 4.9 |  |   | $ | 5.1 |  |   | $ | 9.2 |  |   | $ | 10.6 |  |
| Natural gas gathered (BBtu/d) (a)                                                               | 1,926 |  |   | 1,646 |  |   | 1,867 |  |   | 1,573 |  |
| Natural gas processed (BBtu/d) (a) (b)                                                          | 1,677 |  |   | 1,447 |  |   | 1,651 |  |   | 1,358 |  |
| NGL sales (MBbl/d) (a)                                                                          | 127 |  |   | 98 |  |   | 117 |  |   | 94 |  |
| Residue natural gas sales (BBtu/d) (a)                                                          | 864 |  |   | 683 |  |   | 823 |  |   | 626 |  |
| Realized composite NGL net sales price ($/gallon) (a) (c) (d)                                   | $ | 0.38 |  |   | $ | 0.96 |  |   | $ | 0.38 |  |   | $ | 1.00 |  |
| Realized condensate net sales price ($/Bbl) (a) (c) (e)                                         | $ | 35.46 |  |   | $ | 77.46 |  |   | $ | 32.89 |  |   | $ | 76.80 |  |
| Realized residue gas net sales price ($/MMBtu) (a) (c)                                          | $ | 3.38 |  |   | $ | 4.07 |  |   | $ | 3.65 |  |   | $ | 3.85 |  |
| Average fee rate ($/MMBtu) (a)                                                             | $ | 0.39 |  |   | $ | 0.34 |  |   | $ | 0.37 |  |   | $ | 0.36 |  |
| Capital expenditures - growth                                                                   | $ | 195.5 |  |   | $ | 159.5 |  |   | $ | 440.5 |  |   | $ | 272.7 |  |
| Capital expenditures - maintenance                                                              | $ | 9.9 |  |   | $ | 8.7 |  |   | $ | 20.2 |  |   | $ | 18.4 |  |
| (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 ONEOK Partners’ equity volumes.        |   |   |   |   |
| (d) - Net of transportation and fractionation costs.                                            |   |   |   |   |   |   |   |
| (e) - Net of transportation costs.                                                              |   |   |   |   |   |   |   |

----

|                                                                              |
|------------------------------------------------------------------------------|
|                                                                              |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| ONEOK Partners, L.P. and Subsidiaries                                        |   |   |   |   |   |   |   |
| RECONCILIATION OF NON-GAAP FINANCIAL MEASURES                                |   |   |   |   |   |   |
|                                                                         |   |   |   |   |   |   |   |
|                                                                         | Three Months Ended |   | Six Months Ended |
|                                                                         | June 30, |   | June 30, |
| (Unaudited)                                                                  | 2015 |   | 2014 |   | 2015 |   | 2014 |
|                                                                         |   |
| Reconciliation of Net Income to Adjusted EBITDA and Distributable Cash Flow  |   |   |   |   |
| Net income                                                                   | $ | 211,610 |  |   | $ | 214,511 |  |   | $ | 358,642 |  |   | $ | 479,979 |  |
| Interest expense                                                             | 86,492 |  |   | 73,008 |  |   | 167,201 |  |   | 141,284 |  |
| Depreciation and amortization                                                | 86,199 |  |   | 71,447 |  |   | 172,046 |  |   | 138,182 |  |
| Income taxes                                                                 | 2,476 |  |   | 3,194 |  |   | 5,236 |  |   | 7,375 |  |
| Allowance for equity funds used during construction and other non-cash items | 500 |  |   | (1,253 | ) |   | 8,450 |  |   | (12,224 | ) |
| Adjusted EBITDA                                                              | 387,277 |  |   | 360,907 |  |   | 711,575 |  |   | 754,596 |  |
| Interest expense                                                             | (86,492 | ) |   | (73,008 | ) |   | (167,201 | ) |   | (141,284 | ) |
| Maintenance capital                                                          | (31,978 | ) |   | (30,710 | ) |   | (63,995 | ) |   | (57,562 | ) |
| Equity in net earnings from investments                                      | (30,040 | ) |   | (25,435 | ) |   | (60,961 | ) |   | (59,094 | ) |
| Distributions received from unconsolidated affiliates                        | 41,354 |  |   | 42,579 |  |   | 80,783 |  |   | 77,649 |  |
| Other                                                                        | (3,194 | ) |   | (2,334 | ) |   | (6,063 | ) |   | (4,154 | ) |
| Distributable cash flow                                                      | $ | 276,927 |  |   | $ | 271,999 |  |   | $ | 494,138 |  |   | $ | 570,151 |  |
|                                                                         |   |   |   |   |   |   |   |
| Distributions to general partner                                             | (97,875 | ) |   | (85,882 | ) |   | (193,719 | ) |   | (162,804 | ) |
| Distributable cash flow to limited partners                                  | $ | 179,052 |  |   | $ | 186,117 |  |   | $ | 300,419 |  |   | $ | 407,347 |  |
|                                                                         |   |   |   |   |   |   |   |
| Distributions declared per limited partner unit                              | $ | 0.79 |  |   | $ | 0.76 |  |   | $ | 1.58 |  |   | $ | 1.51 |  |
| Coverage ratio                                                               | 0.88 |  |   | 1.02 |  |   | 0.74 |  |   | 1.14 |  |
|                                                                         |   |   |   |   |   |   |   |
| Number of units used in computation (thousands)                              | 257,179 |  |   | 240,503 |  |   | 255,627 |  |   | 236,361 |  |