----

|         |                                                                                                                                                                                              |
|---------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Lowered full-year capital investment guidance to a range of $810 to $840 million from $810 to $870 million, which includes reducing the Wattenberg rig count from three to two in September. |

|         |                                                                                                                                                                                                                      |
|---------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Reduced corporate headcount in June by approximately 15 percent to more closely align with the updated operational plan, contributing to second half projected 2019 G&A expense between $2.60 and $2.80 per Boe. |

|         |                                                                                                                                                                                                      |
|---------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Increased full-year production to a range of 48 to 50 MMBoe, reflecting the benefit of increased operational efficiencies in both basins driving increased production in the first half of the year. |

|         |                                                                                                                                                                                |
|---------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Returned $125 million to shareholders through July with the repurchase of approximately 3.7 million shares via the previously announced $200 million stock repurchase program. |

|         |                                                                                                                                                                                            |
|---------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Received approximately $264 million of cash in the second quarter from closing of all three Delaware midstream sales. An additional unconditional payment of $82 million is due June 2020. |

|         |                                                                                                                               |
|---------|-------------------------------------------------------------------------------------------------------------------------------|
| • | Received nearly $35 million through the sale of approximately 6,500 net Delaware acres that were scheduled to expire in 2019. |

|         |                                                                                                                                                                                        |
|---------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Oil production of 4.9 MMBbls, or approximately 53,800 Bbls per day, a 24 percent increase from the second quarter of 2018 and a seven percent increase from the first quarter of 2019. |

|         |                                                                                                                                                                                        |
|---------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Total production of 12.4 MMBoe, or approximately 136,500 Boe per day, a 32 percent increase from the second quarter of 2018 and a ten percent increase from the first quarter of 2019. |

----

|         |                                                                                                                                          |
|---------|------------------------------------------------------------------------------------------------------------------------------------------|
| • | LOE of $2.76 per Boe, a 20 percent improvement from the second quarter of 2018 and a 12 percent decrease from the first quarter of 2019. |

|         |                                                                                                                                                                        |
|---------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Further improved Delaware basin drill times, from spud to rig release, to an average of 23 days, a 33 percent, or 11 day improvement, from the second quarter of 2018. |

----

----

|                             |
|-----------------------------|
|                             |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|                        |   | Three Months Ended June 30, |   | Six Months Ended June 30, |
|                        |   | 2019 |   | 2018 |   | Percent Change |   | 2019 |   | 2018 |   | Percent Change |
|                        |   |   |   |   |   |   |   |   |   |   |   |   |
| Crude oil (MBbls)           |   |   |   |   |   |   |   |   |   |   |   |   |
| Wattenberg Field            |   | 3,681 |  |   | 2,943 |  |   | 25.1 |  % |   | 7,253 |  |   | 5,823 |  |   | 24.6 |  % |
| Delaware Basin              |   | 1,218 |  |   | 1,005 |  |   | 21.2 |  % |   | 2,172 |  |   | 1,876 |  |   | 15.8 |  % |
| Utica Shale                 |   | — |  |   | — |  |   | * |  |   | — |  |   | 46 |  |   | * |  |
| Total                       |   | 4,899 |  |   | 3,948 |  |   | 24.1 |  % |   | 9,425 |  |   | 7,745 |  |   | 21.7 |  % |
|                        |   |   |   |   |   |   |   |   |   |   |   |   |
| Weighted-average price      |   | $ | 55.96 |  |   | $ | 63.99 |  |   | (12.5 | )% |   | $ | 53.61 |  |   | $ | 61.85 |  |   | (13.3 | )% |
|                        |   |   |   |   |   |   |   |   |   |   |   |   |
|  Natural gas (MMcf)    |   |   |   |   |   |   |   |   |   |   |   |   |
| Wattenberg Field            |   | 23,233 |  |   | 15,836 |  |   | 46.7 |  % |   | 44,193 |  |   | 31,360 |  |   | 40.9 |  % |
| Delaware Basin              |   | 5,759 |  |   | 4,851 |  |   | 18.7 |  % |   | 10,450 |  |   | 8,500 |  |   | 22.9 |  % |
| Utica Shale                 |   | — |  |   | — |  |   | * |  |   | — |  |   | 414 |  |   | * |  |
| Total                       |   | 28,992 |  |   | 20,687 |  |   | 40.1 |  % |   | 54,643 |  |   | 40,274 |  |   | 35.7 |  % |
|                        |   |   |   |   |   |   |   |   |   |   |   |   |
| Weighted-average price      |   | $ | 1.07 |  |   | $ | 1.46 |  |   | (26.7 | )% |   | $ | 1.53 |  |   | $ | 1.71 |  |   | (10.5 | )% |
|                        |   |   |   |   |   |   |   |   |   |   |   |   |
| NGLs (MBbls)                |   |   |   |   |   |   |   |   |   |   |   |   |
| Wattenberg Field            |   | 2,007 |  |   | 1,544 |  |   | 30.0 |  % |   | 3,908 |  |   | 2,973 |  |   | 31.4 |  % |
| Delaware Basin              |   | 686 |  |   | 443 |  |   | 54.9 |  % |   | 1,200 |  |   | 826 |  |   | 45.3 |  % |
| Utica Shale                 |   | — |  |   | — |  |   | * |  |   | — |  |   | 34 |  |   | * |  |
| Total                       |   | 2,693 |  |   | 1,987 |  |   | 35.5 |  % |   | 5,108 |  |   | 3,833 |  |   | 33.3 |  % |
|                        |   |   |   |   |   |   |   |   |   |   |   |   |
| Weighted-average price      |   | $ | 12.53 |  |   | $ | 21.76 |  |   | (42.4 | )% |   | $ | 13.96 |  |   | $ | 21.78 |  |   | (35.9 | )% |
|                        |   |   |   |   |   |   |   |   |   |   |   |   |
| Crude oil equivalent (MBoe) |   |   |   |   |   |   |   |   |   |   |   |   |
| Wattenberg Field            |   | 9,561 |  |   | 7,126 |  |   | 34.2 |  % |   | 18,526 |  |   | 14,023 |  |   | 32.1 |  % |
| Delaware Basin              |   | 2,864 |  |   | 2,256 |  |   | 27.0 |  % |   | 5,114 |  |   | 4,118 |  |   | 24.2 |  % |
| Utica Shale                 |   | — |  |   | — |  |   | * |  |   | — |  |   | 149 |  |   | * |  |
| Total                       |   | 12,425 |  |   | 9,382 |  |   | 32.4 |  % |   | 23,640 |  |   | 18,290 |  |   | 29.3 |  % |
|                        |   |   |   |   |   |   |   |   |   |   |   |   |
| Weighted-average price      |   | $ | 27.28 |  |   | $ | 34.74 |  |   | (21.5 | )% |   | $ | 27.92 |  |   | $ | 34.51 |  |   | (19.1 | )% |

----

|                                                   |
|---------------------------------------------------|
|                                                   |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|                                              | Three Months Ended June 30, |   | Six Months Ended June 30, |
|                                              | 2019 |   | 2018 |   | 2019 |   | 2018 |
|                                              |   |   |   |   |   |   |   |
| Lease operating expenses                          | $ | 34.3 |  |   | $ | 32.3 |  |   | $ | 69.5 |  |   | $ | 61.9 |  |
| Production taxes                                  | 22.6 |  |   | 22.6 |  |   | 44.8 |  |   | 42.8 |  |
| Transportation, gathering and processing expenses | 12.2 |  |   | 9.0 |  |   | 23.6 |  |   | 16.3 |  |
| Total                                             | $ | 69.1 |  |   | $ | 63.9 |  |   | $ | 137.9 |  |   | $ | 121.0 |  |

|                                                           |
|-----------------------------------------------------------|
|                                                           |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|                                                      | Three Months Ended June 30, |   | Six Months Ended June 30, |
|                                                      | 2019 |   | 2018 |   | 2019 |   | 2018 |
|                                                      |   |   |   |   |   |   |   |
| Lease operating expenses per Boe                          | $ | 2.76 |  |   | $ | 3.44 |  |   | $ | 2.94 |  |   | $ | 3.38 |  |
| Production taxes per Boe                                  | 1.82 |  |   | 2.41 |  |   | 1.90 |  |   | 2.34 |  |
| Transportation, gathering and processing expenses per Boe | 0.99 |  |   | 0.96 |  |   | 1.00 |  |   | 0.89 |  |
| Total per Boe                                             | $ | 5.57 |  |   | $ | 6.81 |  |   | $ | 5.84 |  |   | $ | 6.61 |  |

----

|                                                                       |
|-----------------------------------------------------------------------|
|                                                                       |  |  |  |  |  |  |  |
|                                                                  | Low |   | High |
| Production (MMBoe)                                                    | 48.0 |  |   | 50.0 |  |
| Capital Investment in Crude Oil and Natural Gas Properties (millions) | $ | 810 |  |   | $ | 840 |  |
|                                                                  |   |   |   |
| Operating Expenses                                                    |
| Lease operating expense ($/Boe)                                       | $ | 2.85 |  |   | $ | 3.00 |  |
| Transportation, gathering and processing expenses ($/Boe)             | $ | 0.90 |  |   | $ | 1.00 |  |
| Production taxes (% of Crude oil, natural gas & NGL sales)        | 6 | % |   | 7 | % |
| General and administrative expense ($/Boe)                            | $ | 3.00 |  |   | $ | 3.20 |  |
| Estimated Price Realizations (% of NYMEX) (excludes TGP)              |
| Crude oil                                                             | 90% |   | 95% |
| Natural gas                                                           | 40% |   | 45% |
| NGLs                                                                  | 20% |   | 25% |

----

|                                      |
|--------------------------------------|
|                                      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| Adjusted Cash Flows from Operations  |
|                                 |   | Three Months Ended June 30, |   | Six Months Ended June 30, |
|                                 |   | 2019 |   | 2018 |   | 2019 |   | 2018 |
| Adjusted cash flows from operations: |   |   |   |   |   |   |   |   |
| Net cash from operating activities   |   | $ | 260.4 |  |   | $ | 175.7 |  |   | $ | 442.2 |  |   | $ | 380.9 |  |
| Changes in assets and liabilities    |   | (53.4 | ) |   | 23.6 |  |   | (42.7 | ) |   | (6.6 | ) |
| Adjusted cash flows from operations  |   | $ | 207.0 |  |   | $ | 199.3 |  |   | $ | 399.5 |  |   | $ | 374.3 |  |

|                                                     |
|-----------------------------------------------------|
|                                                     |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| Adjusted Net Income (Loss)                          |
|                                                |   | Three Months Ended June 30, |   | Six Months Ended June 30, |
|                                                |   | 2019 |   | 2018 |   | 2019 |   | 2018 |
| Adjusted net income (loss):                         |   |   |   |   |   |   |   |   |
| Net income (loss)                                   |   | $ | 68.5 |  |   | $ | (160.3 | ) |   | $ | (51.6 | ) |   | $ | (173.4 | ) |
| (Gain) loss on commodity derivative instruments     |   | (47.3 | ) |   | 116.1 |  |   | 142.7 |  |   | 163.4 |  |
| Net settlements on commodity derivative instruments |   | (13.2 | ) |   | (16.4 | ) |   | (21.6 | ) |   | (42.4 | ) |
| Tax effect of above adjustments                     |   | 14.5 |  |   | (23.9 | ) |   | (29.0 | ) |   | (29.0 | ) |
| Adjusted net income (loss)                          |   | $ | 22.5 |  |   | $ | (84.5 | ) |   | $ | 40.5 |  |   | $ | (81.4 | ) |
| Weighted-average diluted shares outstanding         |   | 65.9 |  |   | 66.1 |  |   | 66.0 |  |   | 66.0 |  |
| Adjusted diluted earnings per share                 |   | $ | 0.34 |  |   | $ | (1.28 | ) |   | $ | 0.61 |  |   | $ | (1.23 | ) |

|                                                     |
|-----------------------------------------------------|
|                                                     |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| Adjusted EBITDAX                                    |
|                                                |   | Three Months Ended June 30, |   | Six Months Ended June 30, |
|                                                |   | 2019 |   | 2018 |   | 2019 |   | 2018 |
| Net income (loss) to adjusted EBITDAX:              |   |   |   |   |   |   |   |   |
| Net income (loss)                                   |   | $ | 68.5 |  |   | $ | (160.3 | ) |   | $ | (51.6 | ) |   | $ | (173.4 | ) |
| (Gain) loss on commodity derivative instruments     |   | (47.3 | ) |   | 116.1 |  |   | 142.7 |  |   | 163.4 |  |
| Net settlements on commodity derivative instruments |   | (13.2 | ) |   | (16.4 | ) |   | (21.6 | ) |   | (42.4 | ) |
| Non-cash stock-based compensation                   |   | 7.6 |  |   | 5.5 |  |   | 12.3 |  |   | 10.8 |  |
| Interest expense, net                               |   | 18.9 |  |   | 17.3 |  |   | 35.9 |  |   | 34.7 |  |
| Income tax expense (benefit)                        |   | 22.6 |  |   | (45.3 | ) |   | (14.8 | ) |   | (49.9 | ) |
| Impairment of properties and equipment              |   | 29.0 |  |   | 159.5 |  |   | 36.9 |  |   | 192.7 |  |
| Exploration, geologic and geophysical expense       |   | 0.6 |  |   | 0.9 |  |   | 3.3 |  |   | 3.5 |  |
| Depreciation, depletion and amortization            |   | 168.5 |  |   | 135.6 |  |   | 319.9 |  |   | 262.4 |  |
| Accretion of asset retirement obligations           |   | 1.6 |  |   | 1.4 |  |   | 3.1 |  |   | 2.6 |  |
| Adjusted EBITDAX                                    |   | $ | 256.8 |  |   | $ | 214.3 |  |   | $ | 466.1 |  |   | $ | 404.4 |  |
|                                                |   |   |   |   |   |   |   |   |
| Cash from operating activities to adjusted EBITDAX: |   |   |   |   |   |   |   |   |
| Net cash from operating activities                  |   | $ | 260.4 |  |   | $ | 175.7 |  |   | $ | 442.2 |  |   | $ | 380.9 |  |
| Interest expense, net                               |   | 18.9 |  |   | 17.3 |  |   | 35.9 |  |   | 34.7 |  |
| Amortization of debt discount and issuance costs    |   | (3.4 | ) |   | (3.1 | ) |   | (6.7 | ) |   | (6.4 | ) |
| Gain (loss) on sale of properties and equipment     |   | 33.9 |  |   | 0.4 |  |   | 34.3 |  |   | (1.1 | ) |
| Exploration, geologic and geophysical expense       |   | 0.6 |  |   | 0.9 |  |   | 3.3 |  |   | 3.5 |  |
| Other                                               |   | (0.2 | ) |   | (0.5 | ) |   | (0.2 | ) |   | (0.6 | ) |
| Changes in assets and liabilities                   |   | (53.4 | ) |   | 23.6 |  |   | (42.7 | ) |   | (6.6 | ) |
| Adjusted EBITDAX                                    |   | $ | 256.8 |  |   | $ | 214.3 |  |   | $ | 466.1 |  |   | $ | 404.4 |  |

----

|                                                   |
|---------------------------------------------------|
|                                                   |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|                                              | Three Months Ended June 30, |   | Six Months Ended June 30, |
|                                              | 2019 |   | 2018 |   | 2019 |   | 2018 |
|                                              |   |   |   |   |   |   |   |
| Revenues                                          |   |   |   |   |   |   |   |
| Crude oil, natural gas and NGLs sales             | $ | 338,956 |  |   | $ | 325,933 |  |   | $ | 660,055 |  |   | $ | 631,158 |  |
| Commodity price risk management gain (loss), net  | 47,349 |  |   | (116,126 | ) |   | (142,725 | ) |   | (163,366 | ) |
| Other income                                      | 4,353 |  |   | 2,724 |  |   | 7,828 |  |   | 5,339 |  |
| Total revenues                                    | 390,658 |  |   | 212,531 |  |   | 525,158 |  |   | 473,131 |  |
| Costs, expenses and other                         |   |   |   |   |   |   |   |
| Lease operating expenses                          | 34,328 |  |   | 32,260 |  |   | 69,549 |  |   | 61,896 |  |
| Production taxes                                  | 22,642 |  |   | 22,604 |  |   | 44,810 |  |   | 42,773 |  |
| Transportation, gathering and processing expenses | 12,208 |  |   | 8,964 |  |   | 23,632 |  |   | 16,277 |  |
| Exploration, geologic and geophysical expense     | 640 |  |   | 875 |  |   | 3,283 |  |   | 3,521 |  |
| Impairment of properties and equipment            | 28,979 |  |   | 159,554 |  |   | 36,854 |  |   | 192,742 |  |
| General and administrative expense                | 42,808 |  |   | 37,247 |  |   | 82,406 |  |   | 72,943 |  |
| Depreciation, depletion and amortization          | 168,523 |  |   | 135,624 |  |   | 319,945 |  |   | 262,412 |  |
| Accretion of asset retirement obligations         | 1,563 |  |   | 1,285 |  |   | 3,147 |  |   | 2,573 |  |
| (Gain) loss on sale of properties and equipment   | (33,904 | ) |   | (351 | ) |   | (34,273 | ) |   | 1,081 |  |
| Other expenses                                    | 2,836 |  |   | 2,708 |  |   | 6,390 |  |   | 5,476 |  |
| Total costs, expenses and other                   | 280,623 |  |   | 400,770 |  |   | 555,743 |  |   | 661,694 |  |
| Income (loss) from operations                     | 110,035 |  |   | (188,239 | ) |   | (30,585 | ) |   | (188,563 | ) |
| Interest expense                                  | (18,905 | ) |   | (17,410 | ) |   | (35,883 | ) |   | (34,939 | ) |
| Interest income                                   | 5 |  |   | 69 |  |   | 15 |  |   | 217 |  |
| Income (loss) before income taxes                 | 91,135 |  |   | (205,580 | ) |   | (66,453 | ) |   | (223,285 | ) |
| Income tax (expense) benefit                      | (22,587 | ) |   | 45,323 |  |   | 14,825 |  |   | 49,889 |  |
| Net income (loss)                                 | $ | 68,548 |  |   | $ | (160,257 | ) |   | $ | (51,628 | ) |   | $ | (173,396 | ) |
|                                              |   |   |   |   |   |   |   |
| Earnings per share:                               |   |   |   |   |   |   |   |
| Basic                                             | $ | 1.04 |  |   | $ | (2.43 | ) |   | $ | (0.78 | ) |   | $ | (2.63 | ) |
| Diluted                                           | $ | 1.04 |  |   | $ | (2.43 | ) |   | $ | (0.78 | ) |   | $ | (2.63 | ) |
|                                              |   |   |   |   |   |   |   |
| Weighted-average common shares outstanding:       |   |   |   |   |   |   |   |
| Basic                                             | 65,815 |  |   | 66,066 |  |   | 65,998 |  |   | 66,012 |  |
| Diluted                                           | 65,926 |  |   | 66,066 |  |   | 65,998 |  |   | 66,012 |  |

----

|                                                                                                                                                             |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------|
|                                                                                                                                                             |  |  |  |  |  |  |  |  |
|                                                                                                                                                        |   | June 30, 2019 |   | December 31, 2018 |
| Assets                                                                                                                                                      |   |   |   |   |
| Current assets:                                                                                                                                             |   |   |   |   |
| Cash and cash equivalents                                                                                                                                   |   | $ | 1,474 |  |   | $ | 1,398 |  |
| Accounts receivable, net                                                                                                                                    |   | 277,321 |  |   | 181,434 |  |
| Fair value of derivatives                                                                                                                                   |   | 41,425 |  |   | 84,492 |  |
| Prepaid expenses and other current assets                                                                                                                   |   | 5,607 |  |   | 7,136 |  |
| Total current assets                                                                                                                                        |   | 325,827 |  |   | 274,460 |  |
| Properties and equipment, net                                                                                                                               |   | 4,196,335 |  |   | 4,002,862 |  |
| Assets held-for-sale, net                                                                                                                                   |   | — |  |   | 140,705 |  |
| Fair value of derivatives                                                                                                                                   |   | 31,655 |  |   | 93,722 |  |
| Other assets                                                                                                                                                |   | 41,087 |  |   | 32,396 |  |
| Total Assets                                                                                                                                                |   | $ | 4,594,904 |  |   | $ | 4,544,145 |  |
|                                                                                                                                                        |   |   |   |   |
| Liabilities and Stockholders' Equity                                                                                                                        |   |   |   |   |
| Liabilities                                                                                                                                                 |   |   |   |   |
| Current liabilities:                                                                                                                                        |   |   |   |   |
| Accounts payable                                                                                                                                            |   | $ | 219,158 |  |   | $ | 181,864 |  |
| Production tax liability                                                                                                                                    |   | 69,951 |  |   | 60,719 |  |
| Fair value of derivatives                                                                                                                                   |   | 19,775 |  |   | 3,364 |  |
| Funds held for distribution                                                                                                                                 |   | 88,879 |  |   | 105,784 |  |
| Accrued interest payable                                                                                                                                    |   | 14,273 |  |   | 14,150 |  |
| Other accrued expenses                                                                                                                                      |   | 86,523 |  |   | 75,133 |  |
| Total current liabilities                                                                                                                                   |   | 498,559 |  |   | 441,014 |  |
| Long-term debt                                                                                                                                              |   | 1,197,744 |  |   | 1,194,876 |  |
| Deferred income taxes                                                                                                                                       |   | 183,120 |  |   | 198,096 |  |
| Asset retirement obligations                                                                                                                                |   | 78,909 |  |   | 85,312 |  |
| Liabilities held-for-sale                                                                                                                                   |   | — |  |   | 4,111 |  |
| Fair value of derivatives                                                                                                                                   |   | 927 |  |   | 1,364 |  |
| Other liabilities                                                                                                                                           |   | 257,239 |  |   | 92,664 |  |
| Total liabilities                                                                                                                                           |   | 2,216,498 |  |   | 2,017,437 |  |
|                                                                                                                                                        |   |   |   |   |
| Stockholders' equity                                                                                                                                        |   |   |   |   |
| Common shares - par value $0.01 per share, 150,000,000 authorized, 63,520,462 and 66,148,609 issued as of June 30, 2019 and December 31, 2018, respectively |   | 635 |  |   | 661 |  |
| Additional paid-in capital                                                                                                                                  |   | 2,433,974 |  |   | 2,519,423 |  |
| Retained earnings (deficit)                                                                                                                                 |   | (42,901 | ) |   | 8,727 |  |
| Treasury shares - at cost, 364,780 and 45,220 as of June 30, 2019 and December 31, 2018, respectively                                                       |   | (13,302 | ) |   | (2,103 | ) |
| Total stockholders' equity                                                                                                                                  |   | 2,378,406 |  |   | 2,526,708 |  |
| Total Liabilities and Stockholders' Equity                                                                                                                  |   | $ | 4,594,904 |  |   | $ | 4,544,145 |  |
|                                                                                                                                                        |   |   |   |   |

----

|                                                                                               |
|-----------------------------------------------------------------------------------------------|
|                                                                                               |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|                                                                                          |   | Three Months Ended June 30, |   | Six Months Ended June 30, |
|                                                                                          |   | 2019 |   | 2018 |   | 2019 |   | 2018 |
| Cash flows from operating activities:                                                         |   |   |   |   |   |   |   |   |
| Net income (loss)                                                                             |   | $ | 68,548 |  |   | $ | (160,257 | ) |   | $ | (51,628 | ) |   | $ | (173,396 | ) |
| Adjustments to net income (loss) to reconcile to net cash from operating activities:          |   |   |   |   |   |   |   |   |
| Net change in fair value of unsettled commodity derivatives                                   |   | (60,542 | ) |   | 99,718 |  |   | 121,080 |  |   | 120,920 |  |
| Depreciation, depletion and amortization                                                      |   | 168,523 |  |   | 135,624 |  |   | 319,945 |  |   | 262,412 |  |
| Impairment of properties and equipment                                                        |   | 28,979 |  |   | 159,554 |  |   | 36,854 |  |   | 192,742 |  |
| Accretion of asset retirement obligations                                                     |   | 1,563 |  |   | 1,285 |  |   | 3,147 |  |   | 2,573 |  |
| Non-cash stock-based compensation                                                             |   | 7,575 |  |   | 5,518 |  |   | 12,258 |  |   | 10,779 |  |
| (Gain) loss on sale of properties and equipment                                               |   | (33,904 | ) |   | (351 | ) |   | (34,273 | ) |   | 1,081 |  |
| Amortization of debt discount and issuance costs                                              |   | 3,382 |  |   | 3,126 |  |   | 6,731 |  |   | 6,372 |  |
| Deferred income taxes                                                                         |   | 22,512 |  |   | (45,372 | ) |   | (14,975 | ) |   | (50,181 | ) |
| Other                                                                                         |   | 374 |  |   | 459 |  |   | 395 |  |   | 974 |  |
| Changes in assets and liabilities                                                             |   | 53,373 |  |   | (23,596 | ) |   | 42,702 |  |   | 6,581 |  |
| Net cash from operating activities                                                            |   | 260,383 |  |   | 175,708 |  |   | 442,236 |  |   | 380,857 |  |
| Cash flows from investing activities:                                                         |   |   |   |   |   |   |   |   |
| Capital expenditures for development of crude oil and natural gas properties                  |   | (275,851 | ) |   | (235,718 | ) |   | (542,791 | ) |   | (432,635 | ) |
| Capital expenditures for other properties and equipment                                       |   | (5,627 | ) |   | (1,384 | ) |   | (10,453 | ) |   | (2,450 | ) |
| Acquisition of crude oil and natural gas properties                                           |   | (4,146 | ) |   | (227 | ) |   | (4,146 | ) |   | (181,052 | ) |
| Proceeds from sale of properties and equipment                                                |   | 1,052 |  |   | 1,762 |  |   | 1,154 |  |   | 1,782 |  |
| Proceeds from divestitures                                                                    |   | 199,430 |  |   | — |  |   | 199,430 |  |   | 39,023 |  |
| Restricted cash                                                                               |   | 8,001 |  |   | — |  |   | 8,001 |  |   | 1,249 |  |
| Net cash from investing activities                                                            |   | (77,141 | ) |   | (235,567 | ) |   | (348,805 | ) |   | (574,083 | ) |
| Cash flows from financing activities:                                                         |   |   |   |   |   |   |   |   |
| Proceeds from revolving credit facility                                                       |   | 458,000 |  |   | 198,000 |  |   | 890,000 |  |   | 233,000 |  |
| Repayment of revolving credit facility                                                        |   | (552,000 | ) |   | (176,000 | ) |   | (892,500 | ) |   | (211,000 | ) |
| Payment of debt issuance costs                                                                |   | (36 | ) |   | (4,060 | ) |   | (36 | ) |   | (4,060 | ) |
| Purchase of treasury shares                                                                   |   | (94,113 | ) |   | — |  |   | (94,113 | ) |   | — |  |
| Purchase of treasury shares for employee stock-based compensation tax withholding obligations |   | (2,257 | ) |   | (2,239 | ) |   | (3,717 | ) |   | (4,494 | ) |
| Other                                                                                         |   | (475 | ) |   | (340 | ) |   | (990 | ) |   | (719 | ) |
| Net cash from financing activities                                                            |   | (190,881 | ) |   | 15,361 |  |   | (101,356 | ) |   | 12,727 |  |
| Net change in cash, cash equivalents and restricted cash                                      |   | (7,639 | ) |   | (44,498 | ) |   | (7,925 | ) |   | (180,499 | ) |
| Cash, cash equivalents and restricted cash, beginning of period                               |   | 9,113 |  |   | 53,924 |  |   | 9,399 |  |   | 189,925 |  |
| Cash, cash equivalents and restricted cash, end of period                                     |   | $ | 1,474 |  |   | $ | 9,426 |  |   | $ | 1,474 |  |   | $ | 9,426 |  |

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|         |                                                                                                                                                 |
|---------|-------------------------------------------------------------------------------------------------------------------------------------------------|
| • | changes in global production volumes and demand, including economic conditions that might impact demand and prices for the products we produce; |

|         |                                                                                                                                                    |
|---------|----------------------------------------------------------------------------------------------------------------------------------------------------|
| • | volatility of commodity prices for crude oil, natural gas and natural gas liquids ("NGLs") and the risk of an extended period of depressed prices; |

|         |                                                                                                                                   |
|---------|-----------------------------------------------------------------------------------------------------------------------------------|
| • | impact to our operations, personnel retention, strategy, stock price and expenses caused by the actions of activist shareholders; |

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|         |                                           |
|---------|-------------------------------------------|
| • | volatility and widening of differentials; |

|         |                                                                       |
|---------|-----------------------------------------------------------------------|
| • | reductions in the borrowing base under our revolving credit facility; |

|         |                                                                                                                                                                                                                                                                  |
|---------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | impact of governmental policies and/or regulations, including changes in environmental and other laws, the interpretation and enforcement of those laws and regulations, liabilities arising thereunder and the costs to comply with those laws and regulations; |

|         |                                                                                                   |
|---------|---------------------------------------------------------------------------------------------------|
| • | declines in the value of our crude oil, natural gas and NGLs properties resulting in impairments; |

|         |                                          |
|---------|------------------------------------------|
| • | changes in estimates of proved reserves; |

|         |                                                                |
|---------|----------------------------------------------------------------|
| • | inaccuracy of reserve estimates and expected production rates; |

|         |                                                                                    |
|---------|------------------------------------------------------------------------------------|
| • | potential for production decline rates from our wells being greater than expected; |

|         |                                                                                                |
|---------|------------------------------------------------------------------------------------------------|
| • | timing and extent of our success in discovering, acquiring, developing and producing reserves; |

|         |                                                                                                                                                                                                                                                             |
|---------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | availability of sufficient pipeline, gathering and other transportation facilities and related infrastructure to process and transport our production and the impact of these facilities and regional capacity on the prices we receive for our production; |

|         |                                                     |
|---------|-----------------------------------------------------|
| • | timing and receipt of necessary regulatory permits; |

|         |                                                                                    |
|---------|------------------------------------------------------------------------------------|
| • | risks incidental to the drilling and operation of crude oil and natural gas wells; |

|         |                                                                                                              |
|---------|--------------------------------------------------------------------------------------------------------------|
| • | difficulties in integrating our operations as a result of any significant acquisitions or acreage exchanges; |

|         |                                             |
|---------|---------------------------------------------|
| • | increases or changes in costs and expenses; |

|         |                                                                                                                       |
|---------|-----------------------------------------------------------------------------------------------------------------------|
| • | availability of supplies, materials, contractors and services that may delay the drilling or completion of our wells; |

|         |                                                                    |
|---------|--------------------------------------------------------------------|
| • | potential losses of acreage due to lease expirations or otherwise; |

|         |                                             |
|---------|---------------------------------------------|
| • | increases or changes in costs and expenses; |

|         |                                                       |
|---------|-------------------------------------------------------|
| • | future cash flows, liquidity and financial condition; |

|         |                                              |
|---------|----------------------------------------------|
| • | competition within the oil and gas industry; |

|         |                                   |
|---------|-----------------------------------|
| • | availability and cost of capital; |

|         |                                                           |
|---------|-----------------------------------------------------------|
| • | our success in marketing crude oil, natural gas and NGLs; |

|         |                                                            |
|---------|------------------------------------------------------------|
| • | effect of crude oil and natural gas derivative activities; |

|         |                                                                                                                                                       |
|---------|-------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | impact of environmental events, governmental and other third-party responses to such events and our ability to insure adequately against such events; |

|         |                                       |
|---------|---------------------------------------|
| • | cost of pending or future litigation; |

|         |                                                                          |
|---------|--------------------------------------------------------------------------|
| • | effect that acquisitions we may pursue have on our capital requirements; |

|         |                                                                                     |
|---------|-------------------------------------------------------------------------------------|
| • | our ability to retain or attract senior management and key technical employees; and |

|         |                                                                                    |
|---------|------------------------------------------------------------------------------------|
| • | success of strategic plans, expectations and objectives for our future operations. |

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