----

|         |                                                                                                                     |
|---------|---------------------------------------------------------------------------------------------------------------------|
| • | Full-year net cash from operating activities of approximately $890 million, a 49 percent increase compared to 2017. |

|         |                                                                                                                                                                                                                       |
|---------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Year-over-year production increase of 26 percent to 40.2 million barrels of oil equivalent (“MMBoe”) or approximately 110,000 Boe per day with a December exit rate of approximately 130,000 Boe per day. |

|         |                                                                                                                                                 |
|---------|-------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Oil production of 17.0 million barrels (“MMBbls”), representing 42 percent of total production and a 32 percent increase from 2017. |

|         |                                                                                                                                                                                                                                                   |
|---------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Strengthened financial position including 2018 year-end liquidity of approximately $1.3 billion and a year-end leverage ratio, as defined by the Company’s revolving credit agreement, of 1.4 times compared to 1.9 times at year-end 2017. |

|         |                                                                                                                                                   |
|---------|---------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Increase in year-end proved reserves of approximately 20 percent to 545 MMBoe, with all-sources reserve replacement of approximately 330 percent. |

|         |                                                                                                                                                                                                                                                                                      |
|---------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Added high-value Kersey inventory and consolidated Prairie Area of the Wattenberg Field through a strategic acreage trade that significantly enhances operational efficiencies through increased working interests and longer-laterals while reducing anticipated surface footprint. |

----

----

----

|                                                                    |
|--------------------------------------------------------------------|
|                                                                    |  |  |  |  |  |  |
|                                                               | Low | High |
| Production (MMBoe)                                                 | 46.0 |  | 50.0 |  |
| Capital Investments(1) (millions)                             | $ | 810 |  | $ | 870 |  |
|                                                               |   |   |
| Operating Expenses                                                 |
| Lease operating expenses ("LOE") ($/Boe)                           | $ | 2.85 |  | $ | 3.15 |  |
| Transportation, gathering & processing expense ("TGP") ($/Boe) | $ | 0.80 |  | $ | 1.00 |  |
| Production taxes (% of Crude oil, natural gas & NGLs sales)    | 6 | % | 7 | % |
| General and administrative expense ($/Boe)                         | $ | 3.00 |  | $ | 3.40 |  |
| Estimated Price Realizations (% of NYMEX) (excludes TGP)           |
| Crude Oil                                                          | 90% | 95% |
| Natural Gas                                                        | 50% | 55% |
| NGLs                                                               | 30% | 35% |

----

|                              |
|------------------------------|
|                              |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|                         | Three Months Ended December 31, |   | Twelve Months Ended December 31, |
|                         | 2018 |   | 2017 |   | Percent Change |   | 2018 |   | 2017 |   | Percent Change |
|                         |   |   |   |   |   |   |   |   |   |   |   |
| Crude oil (MBbls)            |   |   |   |   |   |   |   |   |   |   |   |
| Wattenberg Field             | 3,733 |  |   | 3,039 |  |   | 22.8 |  % |   | 12,809 |  |   | 10,922 |  |   | 17.3 |  % |
| Delaware Basin               | 1,190 |  |   | 624 |  |   | 90.7 |  % |   | 4,108 |  |   | 1,699 |  |   | 141.8 |  % |
| Utica Shale (1)              | — |  |   | 55 |  |   | (100.0 | )% |   | 46 |  |   | 281 |  |   | (83.6 | )% |
| Total                        | 4,923 |  |   | 3,718 |  |   | 32.4 |  % |   | 16,963 |  |   | 12,902 |  |   | 31.5 |  % |
|                         |   |   |   |   |   |   |   |   |   |   |   |
| Weighted-Average Sales Price | $ | 55.71 |  |   | $ | 52.79 |  |   | 5.5 |  % |   | $ | 61.19 |  |   | $ | 48.45 |  |   | 26.3 |  % |
|                         |   |   |   |   |   |   |   |   |   |   |   |
| Natural gas (MMcf)           |   |   |   |   |   |   |   |   |   |   |   |
| Wattenberg Field             | 20,157 |  |   | 15,412 |  |   | 30.8 |  % |   | 68,326 |  |   | 60,106 |  |   | 13.7 |  % |
| Delaware Basin               | 5,820 |  |   | 3,358 |  |   | 73.3 |  % |   | 19,277 |  |   | 9,410 |  |   | 104.9 |  % |
| Utica Shale (1)              | — |  |   | 482 |  |   | (100.0 | )% |   | 414 |  |   | 2,173 |  |   | (80.9 | )% |
| Total                        | 25,977 |  |   | 19,252 |  |   | 34.9 |  % |   | 88,017 |  |   | 71,689 |  |   | 22.8 |  % |
|                         |   |   |   |   |   |   |   |   |   |   |   |
| Weighted-Average Sales Price | $ | 2.30 |  |   | $ | 2.16 |  |   | 6.5 |  % |   | $ | 1.85 |  |   | $ | 2.21 |  |   | (16.3 | )% |
|                         |   |   |   |   |   |   |   |   |   |   |   |
| NGLs (MBbls)                 |   |   |   |   |   |   |   |   |   |   |   |
| Wattenberg Field             | 1,839 |  |   | 1,403 |  |   | 31.1 |  % |   | 6,455 |  |   | 5,876 |  |   | 9.9 |  % |
| Delaware Basin               | 678 |  |   | 292 |  |   | 132.2 |  % |   | 2,038 |  |   | 917 |  |   | 122.2 |  % |
| Utica Shale (1)              | — |  |   | 37 |  |   | (100.0 | )% |   | 34 |  |   | 188 |  |   | (81.9 | )% |
| Total                        | 2,517 |  |   | 1,732 |  |   | 45.3 |  % |   | 8,527 |  |   | 6,981 |  |   | 22.1 |  % |
|                         |   |   |   |   |   |   |   |   |   |   |   |
| Weighted-Average Sales Price | $ | 20.79 |  |   | $ | 22.68 |  |   | (8.3 | )% |   | $ | 22.14 |  |   | $ | 18.59 |  |   | 19.1 |  % |
|                         |   |   |   |   |   |   |   |   |   |   |   |
| Crude oil equivalent (MBoe)  |   |   |   |   |   |   |   |   |   |   |   |
| Wattenberg Field             | 8,931 |  |   | 7,010 |  |   | 27.4 |  % |   | 30,652 |  |   | 26,815 |  |   | 14.3 |  % |
| Delaware Basin               | 2,839 |  |   | 1,475 |  |   | 92.5 |  % |   | 9,359 |  |   | 4,184 |  |   | 123.7 |  % |
| Utica Shale (1)              | — |  |   | 173 |  |   | (100.0 | )% |   | 149 |  |   | 831 |  |   | (82.1 | )% |
| Total                        | 11,770 |  |   | 8,658 |  |   | 35.9 |  % |   | 40,160 |  |   | 31,830 |  |   | 26.2 |  % |
|                         |   |   |   |   |   |   |   |   |   |   |   |
| Weighted-Average Sales Price | $ | 32.83 |  |   | $ | 32.00 |  |   | 2.6 |  % |   | $ | 34.61 |  |   | $ | 28.69 |  |   | 20.6 |  % |

----

|                                                   |
|---------------------------------------------------|
|                                                   |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|                                              | Three Months Ended December 31, |   | Twelve Months Ended December 31, |
|                                              | 2018 |   | 2017 |   | 2018 |   | 2017 |
|                                              |   |   |   |   |   |   |   |
| Lease operating expenses                          | $ | 36.0 |  |   | $ | 24.5 |  |   | $ | 131.0 |  |   | $ | 89.6 |  |
| Production taxes                                  | 23.6 |  |   | 17.8 |  |   | 90.4 |  |   | 60.7 |  |
| Transportation, gathering and processing expenses | 11.9 |  |   | 11.0 |  |   | 37.4 |  |   | 33.2 |  |
| Total                                             | $ | 71.5 |  |   | $ | 53.3 |  |   | $ | 258.8 |  |   | $ | 183.5 |  |

|                                                           |
|-----------------------------------------------------------|
|                                                           |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|                                                      | Three Months Ended December 31, |   | Twelve Months Ended December 31, |
|                                                      | 2018 |   | 2017 |   | 2018 |   | 2017 |
|                                                      |   |   |   |   |   |   |   |
| Lease operating expenses per Boe                          | $ | 3.06 |  |   | $ | 2.83 |  |   | $ | 3.26 |  |   | $ | 2.82 |  |
| Production taxes per Boe                                  | 2.01 |  |   | 2.05 |  |   | 2.25 |  |   | 1.91 |  |
| Transportation, gathering and processing expenses per Boe | 1.01 |  |   | 1.27 |  |   | 0.93 |  |   | 1.04 |  |
| Total per Boe                                             | $ | 6.08 |  |   | $ | 6.15 |  |   | $ | 6.44 |  |   | $ | 5.77 |  |

----

----

|                                      |
|--------------------------------------|
|                                      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| Adjusted Cash Flows from Operations  |
|                                 | Three Months Ended December 31, |   | Twelve Months Ended December 31, |
|                                 | 2018 |   | 2017 |   | 2018 |   | 2017 |
| Adjusted cash flows from operations: |   |   |   |   |   |   |   |
| Net cash from operating activities   | $ | 311.5 |  |   | $ | 177.2 |  |   | $ | 889.3 |  |   | $ | 597.8 |  |
| Changes in assets and liabilities    | (78.4 | ) |   | (2.6 | ) |   | (80.9 | ) |   | (15.7 | ) |
| Adjusted cash flows from operations  | $ | 233.1 |  |   | $ | 174.6 |  |   | $ | 808.4 |  |   | $ | 582.1 |  |

|                                                     |
|-----------------------------------------------------|
|                                                     |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| Adjusted Net Income (Loss)                          |
|                                                | Three Months Ended December 31, |   | Twelve Months Ended December 31, |
|                                                | 2018 |   | 2017 |   | 2018 |   | 2017 |
| Adjusted net income (loss):                         |   |   |   |   |   |   |   |
| Net income (loss)                                   | $ | 178.9 |  |   | $ | 77.6 |  |   | $ | 2.0 |  |   | $ | (127.5 | ) |
| (Gain) loss on commodity derivative instruments     | (403.0 | ) |   | 90.4 |  |   | (145.2 | ) |   | 3.9 |  |
| Net settlements on commodity derivative instruments | (25.0 | ) |   | (8.9 | ) |   | (115.5 | ) |   | 13.3 |  |
| Tax effect of above adjustments                     | 102.4 |  |   | (28.2 | ) |   | 62.4 |  |   | (4.1 | ) |
| Adjusted net income (loss)                          | $ | (146.7 | ) |   | $ | 130.9 |  |   | $ | (196.3 | ) |   | $ | (114.4 | ) |
| Weighted-average diluted shares outstanding         | 66.2 |  |   | 66.1 |  |   | 66.3 |  |   | 65.8 |  |
| Adjusted diluted earnings per share                 | $ | (2.22 | ) |   | $ | 1.98 |  |   | $ | (2.96 | ) |   | $ | (1.74 | ) |

----

|                                                     |
|-----------------------------------------------------|
|                                                     |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| Adjusted EBITDAX                                    |
|                                                | Three Months Ended December 31, |   | Twelve Months Ended December 31, |
|                                                | 2018 |   | 2017 |   | 2018 |   | 2017 |
| Net income (loss) to adjusted EBITDAX:              |   |   |   |   |   |   |   |
| Net income (loss)                                   | $ | 178.9 |  |   | $ | 77.6 |  |   | $ | 2.0 |  |   | $ | (127.5 | ) |
| (Gain) loss on commodity derivative instruments     | (403.0 | ) |   | 90.4 |  |   | (145.2 | ) |   | 3.9 |  |
| Net settlements on commodity derivative instruments | (25.0 | ) |   | (8.9 | ) |   | (115.5 | ) |   | 13.3 |  |
| Non-cash stock-based compensation                   | 5.4 |  |   | 4.8 |  |   | 21.8 |  |   | 19.4 |  |
| Interest expense, net                               | 18.1 |  |   | 19.6 |  |   | 70.3 |  |   | 76.4 |  |
| Income tax expense (benefit)                        | 59.1 |  |   | (140.4 | ) |   | 5.4 |  |   | (211.9 | ) |
| Impairment of properties and equipment              | 264.2 |  |   | 3.4 |  |   | 458.4 |  |   | 285.9 |  |
| Impairment of goodwill                              | — |  |   | — |  |   | — |  |   | 75.1 |  |
| Exploration, geologic and geophysical expense       | 1.6 |  |   | 3.4 |  |   | 6.2 |  |   | 47.3 |  |
| Depreciation, depletion and amortization            | 149.8 |  |   | 108.5 |  |   | 559.8 |  |   | 469.1 |  |
| Accretion of asset retirement obligations           | 1.3 |  |   | 1.4 |  |   | 5.1 |  |   | 6.4 |  |
| Loss on extinguishment of debt                      | — |  |   | 24.7 |  |   | — |  |   | 24.7 |  |
| Adjusted EBITDAX                                    | $ | 250.4 |  |   | $ | 184.5 |  |   | $ | 868.3 |  |   | $ | 682.1 |  |
|                                                |   |   |   |   |   |   |   |
| Cash from operating activities to adjusted EBITDAX: |   |   |   |   |   |   |   |
| Net cash from operating activities                  | $ | 311.5 |  |   | $ | 177.2 |  |   | $ | 889.3 |  |   | $ | 597.8 |  |
| Interest expense, net                               | 18.1 |  |   | 19.6 |  |   | 70.3 |  |   | 76.4 |  |
| Amortization of debt discount and issuance costs    | (3.3 | ) |   | (3.3 | ) |   | (12.8 | ) |   | (12.9 | ) |
| Gain (loss) on sale of properties and equipment     | 2.8 |  |   | — |  |   | (0.4 | ) |   | 0.7 |  |
| Exploration, geologic and geophysical expense       | 1.6 |  |   | 3.4 |  |   | 6.2 |  |   | 47.3 |  |
| Exploratory dry hole costs                          | (0.1 | ) |   | (0.1 | ) |   | (0.1 | ) |   | (41.3 | ) |
| Other                                               | (1.8 | ) |   | (9.7 | ) |   | (3.3 | ) |   | 29.8 |  |
| Changes in assets and liabilities                   | (78.4 | ) |   | (2.6 | ) |   | (80.9 | ) |   | (15.7 | ) |
| Adjusted EBITDAX                                    | $ | 250.4 |  |   | $ | 184.5 |  |   | $ | 868.3 |  |   | $ | 682.1 |  |

----

|                                                   |
|---------------------------------------------------|
|                                                   |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|                                              | Three Months Ended December 31, |   | Twelve Months Ended December 31, |
|                                              | 2018 |   | 2017 |   | 2018 |   | 2017 |
|                                              |   |   |   |   |   |   |   |
| Revenues                                          |   |   |   |   |   |   |   |
| Crude oil, natural gas and NGLs sales             | $ | 386,364 |  |   | $ | 277,057 |  |   | $ | 1,389,961 |  |   | $ | 913,084 |  |
| Commodity price risk management gain (loss), net  | 402,997 |  |   | (90,394 | ) |   | 145,237 |  |   | (3,936 | ) |
| Other income                                      | 5,450 |  |   | 2,853 |  |   | 13,461 |  |   | 12,468 |  |
| Total revenues                                    | 794,811 |  |   | 189,516 |  |   | 1,548,659 |  |   | 921,616 |  |
| Costs, expenses and other                         |   |   |   |   |   |   |   |
| Lease operating expenses                          | 36,015 |  |   | 24,471 |  |   | 130,957 |  |   | 89,641 |  |
| Production taxes                                  | 23,600 |  |   | 17,760 |  |   | 90,357 |  |   | 60,717 |  |
| Transportation, gathering and processing expenses | 11,892 |  |   | 11,036 |  |   | 37,403 |  |   | 33,220 |  |
| Exploration, geologic and geophysical expense     | 1,651 |  |   | 3,439 |  |   | 6,204 |  |   | 47,334 |  |
| Impairment of properties and equipment            | 264,167 |  |   | 3,388 |  |   | 458,397 |  |   | 285,887 |  |
| Impairment of goodwill                            | — |  |   | — |  |   | — |  |   | 75,121 |  |
| General and administrative expense                | 49,321 |  |   | 35,225 |  |   | 170,504 |  |   | 120,370 |  |
| Depreciation, depletion and amortization          | 149,841 |  |   | 108,517 |  |   | 559,793 |  |   | 469,084 |  |
| Accretion of asset retirement obligations         | 1,302 |  |   | 1,400 |  |   | 5,075 |  |   | 6,306 |  |
| (Gain) loss on sale of properties and equipment   | (2,805 | ) |   | (12 | ) |   | 394 |  |   | (766 | ) |
| Provision for uncollectible notes receivable      | — |  |   | — |  |   | — |  |   | (40,203 | ) |
| Other expenses                                    | 3,642 |  |   | 2,792 |  |   | 11,829 |  |   | 13,157 |  |
| Total costs, expenses and other                   | 538,626 |  |   | 208,016 |  |   | 1,470,913 |  |   | 1,159,868 |  |
| Income (loss) from operations                     | 256,185 |  |   | (18,500 | ) |   | 77,746 |  |   | (238,252 | ) |
| Loss on extinguishment of debt                    | — |  |   | (24,747 | ) |   | — |  |   | (24,747 | ) |
| Interest expense                                  | (18,169 | ) |   | (20,335 | ) |   | (70,730 | ) |   | (78,694 | ) |
| Interest income                                   | 8 |  |   | 774 |  |   | 413 |  |   | 2,261 |  |
| Income (loss) before income taxes                 | 238,024 |  |   | (62,808 | ) |   | 7,429 |  |   | (339,432 | ) |
| Income tax (expense) benefit                      | (59,171 | ) |   | 140,445 |  |   | (5,406 | ) |   | 211,928 |  |
| Net income (loss)                                 | $ | 178,853 |  |   | $ | 77,637 |  |   | $ | 2,023 |  |   | $ | (127,504 | ) |
|                                              |   |   |   |   |   |   |   |
| Earnings per share:                               |   |   |   |   |   |   |   |
| Basic                                             | $ | 2.71 |  |   | $ | 1.18 |  |   | $ | 0.03 |  |   | $ | (1.94 | ) |
| Diluted                                           | $ | 2.71 |  |   | $ | 1.17 |  |   | $ | 0.03 |  |   | $ | (1.94 | ) |
|                                              |   |   |   |   |   |   |   |
| Weighted-average common shares outstanding:       |   |   |   |   |   |   |   |
| Basic                                             | 66,104 |  |   | 65,875 |  |   | 66,059 |  |   | 65,837 |  |
| Diluted                                           | 66,232 |  |   | 66,085 |  |   | 66,303 |  |   | 65,837 |  |

----

|                                                                                                                                                    |
|----------------------------------------------------------------------------------------------------------------------------------------------------|
|                                                                                                                                                    |  |  |  |  |  |  |  |  |
|                                                                                                                                               |   | December 31, 2018 |   | December 31, 2017 |
| Assets                                                                                                                                             |   |   |   |   |
| Current assets:                                                                                                                                    |   |   |   |   |
| Cash and cash equivalents                                                                                                                          |   | $ | 1,398 |  |   | $ | 180,675 |  |
| Accounts receivable, net                                                                                                                           |   | 181,434 |  |   | 197,598 |  |
| Fair value of derivatives                                                                                                                          |   | 84,492 |  |   | 14,338 |  |
| Prepaid expenses and other current assets                                                                                                          |   | 7,136 |  |   | 8,613 |  |
| Total current assets                                                                                                                               |   | 274,460 |  |   | 401,224 |  |
| Properties and equipment, net                                                                                                                      |   | 4,002,862 |  |   | 3,933,467 |  |
| Assets held-for-sale                                                                                                                               |   | 140,705 |  |   | 40,583 |  |
| Fair value of derivatives                                                                                                                          |   | 93,722 |  |   | — |  |
| Other assets                                                                                                                                       |   | 32,396 |  |   | 45,116 |  |
| Total Assets                                                                                                                                       |   | $ | 4,544,145 |  |   | $ | 4,420,390 |  |
|                                                                                                                                               |   |   |   |   |
| Liabilities and Stockholders' Equity                                                                                                               |   |   |   |   |
| Liabilities                                                                                                                                        |   |   |   |   |
| Current liabilities:                                                                                                                               |   |   |   |   |
| Accounts payable                                                                                                                                   |   | $ | 181,864 |  |   | $ | 150,067 |  |
| Production tax liability                                                                                                                           |   | 60,719 |  |   | 37,654 |  |
| Fair value of derivatives                                                                                                                          |   | 3,364 |  |   | 79,302 |  |
| Funds held for distribution                                                                                                                        |   | 105,784 |  |   | 95,811 |  |
| Accrued interest payable                                                                                                                           |   | 14,150 |  |   | 11,815 |  |
| Other accrued expenses                                                                                                                             |   | 75,133 |  |   | 42,987 |  |
| Total current liabilities                                                                                                                          |   | 441,014 |  |   | 417,636 |  |
| Long-term debt                                                                                                                                     |   | 1,194,876 |  |   | 1,151,932 |  |
| Deferred income taxes                                                                                                                              |   | 198,096 |  |   | 191,992 |  |
| Asset retirement obligations                                                                                                                       |   | 85,312 |  |   | 71,006 |  |
| Liabilities held-for-sale                                                                                                                          |   | 4,111 |  |   | 499 |  |
| Fair value of derivatives                                                                                                                          |   | 1,364 |  |   | 22,343 |  |
| Other liabilities                                                                                                                                  |   | 92,664 |  |   | 57,333 |  |
| Total liabilities                                                                                                                                  |   | 2,017,437 |  |   | 1,912,741 |  |
|                                                                                                                                               |   |   |   |   |
| Commitments and contingent liabilities                                                                                                             |   |   |   |   |
|                                                                                                                                               |   |   |   |   |
| Stockholders' equity                                                                                                                               |   |   |   |   |
| Common shares - par value $0.01 per share, 150,000,000 authorized, 66,148,609 and 65,955,080 issued as of December 31, 2018 and 2017, respectively |   | 661 |  |   | 659 |  |
| Additional paid-in capital                                                                                                                         |   | 2,519,423 |  |   | 2,503,294 |  |
| Retained earnings                                                                                                                                  |   | 8,727 |  |   | 6,704 |  |
| Treasury shares - at cost, 45,220 and 55,927 as of      December 31, 2018 and 2017, respectively                                                   |   | (2,103 | ) |   | (3,008 | ) |
| Total stockholders' equity                                                                                                                         |   | 2,526,708 |  |   | 2,507,649 |  |
| Total Liabilities and Stockholders' Equity                                                                                                         |   | $ | 4,544,145 |  |   | $ | 4,420,390 |  |
|                                                                                                                                               |   |   |   |   |

----

|                                                                                      |
|--------------------------------------------------------------------------------------|
|                                                                                      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|                                                                                 |   | Three Months Ended December 31, |   | Twelve Months Ended December 31, |
|                                                                                 |   | 2018 |   | 2017 |   | 2018 |   | 2017 |
| Cash flows from operating activities:                                                |   |   |   |   |   |   |   |   |
| Net income (loss)                                                                    |   | $ | 178,853 |  |   | $ | 77,637 |  |   | $ | 2,023 |  |   | $ | (127,504 | ) |
| Adjustments to net income (loss) to reconcile to net cash from operating activities: |   |   |   |   |   |   |   |   |
| Net change in fair value of unsettled commodity derivatives                          |   | (427,993 | ) |   | 81,567 |  |   | (260,775 | ) |   | 17,260 |  |
| Depreciation, depletion and amortization                                             |   | 149,841 |  |   | 108,517 |  |   | 559,793 |  |   | 469,084 |  |
| Impairment of properties and equipment                                               |   | 264,167 |  |   | 3,388 |  |   | 458,397 |  |   | 285,887 |  |
| Impairment of goodwill                                                               |   | — |  |   | — |  |   | — |  |   | 75,121 |  |
| Exploratory dry hole costs                                                           |   | 113 |  |   | 110 |  |   | 113 |  |   | 41,297 |  |
| Provision for uncollectible notes receivable                                         |   | — |  |   | — |  |   | — |  |   | (40,203 | ) |
| Loss on extinguishment of debt                                                       |   | — |  |   | 24,747 |  |   | — |  |   | 24,747 |  |
| Accretion of asset retirement obligations                                            |   | 1,302 |  |   | 1,400 |  |   | 5,075 |  |   | 6,306 |  |
| Non-cash stock-based compensation                                                    |   | 5,425 |  |   | 4,766 |  |   | 21,782 |  |   | 19,353 |  |
| (Gain) loss on sale of properties and equipment                                      |   | (2,805 | ) |   | (12 | ) |   | 394 |  |   | (766 | ) |
| Amortization of debt discount and issuance costs                                     |   | 3,315 |  |   | 3,279 |  |   | 12,769 |  |   | 12,907 |  |
| Deferred income taxes                                                                |   | 59,134 |  |   | (132,156 | ) |   | 6,105 |  |   | (203,685 | ) |
| Other                                                                                |   | 1,738 |  |   | 1,279 |  |   | 2,763 |  |   | 2,265 |  |
| Changes in assets and liabilities                                                    |   | 78,378 |  |   | 2,639 |  |   | 80,863 |  |   | 15,744 |  |
| Net cash from operating activities                                                   |   | 311,468 |  |   | 177,161 |  |   | 889,302 |  |   | 597,813 |  |
| Cash flows from investing activities:                                                |   |   |   |   |   |   |   |   |
| Capital expenditures for development of crude oil and natural gas properties         |   | (260,801 | ) |   | (208,358 | ) |   | (946,350 | ) |   | (737,208 | ) |
| Capital expenditures for other properties and equipment                              |   | (7,316 | ) |   | (1,354 | ) |   | (11,055 | ) |   | (5,094 | ) |
| Acquisition of crude oil and natural gas properties                                  |   | 1,546 |  |   | (1,146 | ) |   | (180,026 | ) |   | (15,628 | ) |
| Proceeds from sale of properties and equipment                                       |   | 1,119 |  |   | 6,669 |  |   | 3,562 |  |   | 9,991 |  |
| Proceeds from divestiture                                                            |   | 1,200 |  |   | — |  |   | 44,693 |  |   | — |  |
| Sale of promissory note                                                              |   | — |  |   | — |  |   | — |  |   | 40,203 |  |
| Restricted cash                                                                      |   | — |  |   | — |  |   | 1,249 |  |   | (9,250 | ) |
| Sale of short-term investments                                                       |   | — |  |   | — |  |   | — |  |   | 49,890 |  |
| Purchase of short-term investments                                                   |   | — |  |   | — |  |   | — |  |   | (49,890 | ) |
| Net cash from investing activities                                                   |   | (264,252 | ) |   | (204,189 | ) |   | (1,087,927 | ) |   | (716,986 | ) |
| Cash flows from financing activities:                                                |   |   |   |   |   |   |   |   |
| Proceeds from revolving credit facility                                              |   | 443,500 |  |   | — |  |   | 1,072,500 |  |   | — |  |
| Repayment of revolving credit facility                                               |   | (486,000 | ) |   | — |  |   | (1,040,000 | ) |   | — |  |
| Proceeds from issuance of senior notes                                               |   | — |  |   | 592,366 |  |   | — |  |   | 592,366 |  |
| Redemption of senior notes                                                           |   | — |  |   | (519,375 | ) |   | — |  |   | (519,375 | ) |
| Payment of debt issuance costs                                                       |   | (3,618 | ) |   | (50 | ) |   | (7,704 | ) |   | (50 | ) |
| Purchase of treasury shares                                                          |   | (447 | ) |   | (1,347 | ) |   | (5,147 | ) |   | (6,672 | ) |
|  Other                                                                          |   | (622 | ) |   | (320 | ) |   | (1,550 | ) |   | (1,271 | ) |
| Net cash from financing activities                                                   |   | (47,187 | ) |   | 71,274 |  |   | 18,099 |  |   | 64,998 |  |
| Net change in cash, cash equivalents and restricted cash                             |   | 29 |  |   | 44,246 |  |   | (180,526 | ) |   | (54,175 | ) |
| Cash, cash equivalents and restricted cash, beginning of year                        |   | 9,370 |  |   | 145,679 |  |   | 189,925 |  |   | 244,100 |  |
| Cash, cash equivalents and restricted cash, end of year                              |   | $ | 9,399 |  |   | $ | 189,925 |  |   | $ | 9,399 |  |   | $ | 189,925 |  |

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

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

|         |                                           |
|---------|-------------------------------------------|
| • | 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 related to 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 estimated reserves and 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; |

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|         |                                                                                                                                                                                                                                                             |
|---------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | 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 and acreage exchanges; |

|         |                                                                                                                       |
|---------|-----------------------------------------------------------------------------------------------------------------------|
| • | 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; |

|         |                                                                                                       |
|---------|-------------------------------------------------------------------------------------------------------|
| • | possibility that one or more sales of our Delaware Basin midstream assets will not close as expected; |

|         |                                              |
|---------|----------------------------------------------|
| • | 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, natural gas and NGLs derivatives 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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