----

|         |                                                                                                                                                                                                                  |
|---------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Production of 8.5 million barrels of oil equivalent (“MMBoe”), a 42 percent increase year-over-year; average daily production of approximately 92,500 barrels of oil equivalent (“Boe”). |

|         |                                                                                                     |
|---------|-----------------------------------------------------------------------------------------------------|
| • | Oil production of 3.4 million barrels (“MMBbls”), a 47 percent increase year-over-year. |

|         |                                                                                                               |
|---------|---------------------------------------------------------------------------------------------------------------|
| • | Delaware Basin production averaged 12,845 Boe per day, a 28 percent increase from the second quarter of 2017. |

|         |                                                                                                                                                   |
|---------|---------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Lease operating expense (“LOE”) of $2.98 in the third quarter of 2017 and $2.81 per Boe for the nine months ended September 30, 2017. |

|         |                                                                                                                                                     |
|---------|-----------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Announced strategic acreage trades and bolt-on acquisition in the Core Wattenberg Field, with expected closing dates in the fourth quarter of 2017. |

|         |                                                                                                                                                                                                                 |
|---------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Increased borrowing base to $1.1 billion in October 2017 while maintaining commitment level of $700 million; liquidity was approximately $836 million, including $136 million of cash as of September 30, 2017. |

----

|         |                                                                                                                                                                                                                                                                               |
|---------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | The Elkhead is a 9,700 foot lateral well testing the Wolfcamp B.  The Elkhead, which has yet to reach peak production and is on controlled flowback, has been producing approximately 2,250 Boe per day with approximately 1,550 barrels of oil per day for the past 45 days. |

|         |                                                                                                                                                                                                                   |
|---------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | Production from the Lost Saddle well, the first well with an enhanced perforation completion design, is exceeding internal expectations to-date.  Located in the Eastern acreage block and targeting the Wolfcamp |

----

----

|                              |
|------------------------------|
|                              |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|                         | Three Months Ended September 30, |   | Nine Months EndedSeptember 30, |
|                         | 2017 |   | 2016 |   | Percent |   | 2017 |   | 2016 |   | Percent |
|                         |   |   |   |   |   |   |   |   |   |   |   |
| Crude oil (MBbls)            |   |   |   |   |   |   |   |   |   |   |   |
| Wattenberg Field             | 2,943 |  |   | 2,216 |  |   | 32.8 |  % |   | 7,883 |  |   | 5,929 |  |   | 33.0 |  % |
| Delaware Basin               | 436 |  |   | — |  |   | * |  |   | 1,075 |  |   | — |  |   | * |  |
| Utica Shale                  | 60 |  |   | 124 |  |   | (51.4 | )% |   | 226 |  |   | 312 |  |   | (27.7 | )% |
| Total                        | 3,439 |  |   | 2,340 |  |   | 47.0 |  % |   | 9,184 |  |   | 6,241 |  |   | 47.2 |  % |
|                         |   |   |   |   |   |   |   |   |   |   |   |
| Weighted-Average Sales Price | $ | 45.66 |  |   | $ | 42.11 |  |   | 8.4 |  % |   | $ | 46.69 |  |   | $ | 37.33 |  |   | 25.1 |  % |
|                         |   |   |   |   |   |   |   |   |   |   |   |
| Natural gas (MMcf)           |   |   |   |   |   |   |   |   |   |   |   |
| Wattenberg Field             | 15,788 |  |   | 12,700 |  |   | 24.3 |  % |   | 44,694 |  |   | 34,968 |  |   | 27.8 |  % |
| Delaware Basin               | 2,781 |  |   | — |  |   | * |  |   | 6,052 |  |   | — |  |   | * |  |
| Utica Shale                  | 501 |  |   | 717 |  |   | (30.2 | )% |   | 1,691 |  |   | 1,800 |  |   | (6.0 | )% |
| Total                        | 19,070 |  |   | 13,417 |  |   | 42.1 |  % |   | 52,437 |  |   | 36,768 |  |   | 42.6 |  % |
|                         |   |   |   |   |   |   |   |   |   |   |   |
| Weighted-Average Sales Price | $ | 2.17 |  |   | $ | 2.04 |  |   | 6.4 |  % |   | $ | 2.23 |  |   | $ | 1.62 |  |   | 37.7 |  % |
|                         |   |   |   |   |   |   |   |   |   |   |   |
| NGLs (MBbls)                 |   |   |   |   |   |   |   |   |   |   |   |
| Wattenberg Field             | 1,564 |  |   | 1,353 |  |   | 15.6 |  % |   | 4,473 |  |   | 3,240 |  |   | 38.0 |  % |
| Delaware Basin               | 282 |  |   | — |  |   | * |  |   | 625 |  |   | — |  |   | * |  |
| Utica Shale                  | 46 |  |   | 75 |  |   | (38.7 | )% |   | 151 |  |   | 162 |  |   | (7.3 | )% |
| Total                        | 1,892 |  |   | 1,428 |  |   | 32.5 |  % |   | 5,249 |  |   | 3,402 |  |   | 54.3 |  % |
|                         |   |   |   |   |   |   |   |   |   |   |   |
| Weighted-Average Sales Price | $ | 18.11 |  |   | $ | 11.12 |  |   | 62.9 |  % |   | $ | 17.24 |  |   | $ | 10.41 |  |   | 65.6 |  % |
|                         |   |   |   |   |   |   |   |   |   |   |   |
| Crude oil equivalent (MBoe)  |   |   |   |   |   |   |   |   |   |   |   |
| Wattenberg Field             | 7,138 |  |   | 5,686 |  |   | 25.5 |  % |   | 19,805 |  |   | 14,997 |  |   | 32.1 |  % |
| Delaware Basin               | 1,182 |  |   | — |  |   | * |  |   | 2,709 |  |   | — |  |   | * |  |
| Utica Shale                  | 189 |  |   | 318 |  |   | (40.6 | )% |   | 658 |  |   | 774 |  |   | (15.0 | )% |
| Total                        | 8,509 |  |   | 6,004 |  |   | 41.7 |  % |   | 23,172 |  |   | 15,771 |  |   | 46.9 |  % |
|                         |   |   |   |   |   |   |   |   |   |   |   |
| Weighted-Average Sales Price | $ | 27.35 |  |   | $ | 23.62 |  |   | 15.8 |  % |   | $ | 27.45 |  |   | $ | 20.80 |  |   | 32.0 |  % |

----

|                                                   |
|---------------------------------------------------|
|                                                   |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|                                              | Three Months EndedSeptember 30, |   | Nine Months Ended September 30, |
|                                              | 2017 |   | 2016 |   | 2017 |   | 2016 |
|                                              |   |   |   |   |   |   |   |
| Lease operating expenses                          | $ | 25.4 |  |   | $ | 14.0 |  |   | $ | 65.2 |  |   | $ | 43.0 |  |
| Production taxes                                  | 15.5 |  |   | 9.6 |  |   | 43.0 |  |   | 19.7 |  |
| Transportation, gathering and processing expenses | 9.8 |  |   | 5.0 |  |   | 22.2 |  |   | 13.6 |  |
| Total                                             | $ | 50.7 |  |   | $ | 28.6 |  |   | $ | 130.4 |  |   | $ | 76.3 |  |

|                                                           |
|-----------------------------------------------------------|
|                                                           |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|                                                      | Three Months EndedSeptember 30, |   | Nine Months Ended September 30, |
|                                                      | 2017 |   | 2016 |   | 2017 |   | 2016 |
|                                                      |   |   |   |   |   |   |   |
| Lease operating expenses per Boe                          | $ | 2.98 |  |   | $ | 2.33 |  |   | $ | 2.81 |  |   | $ | 2.73 |  |
| Production taxes per Boe                                  | 1.82 |  |   | 1.59 |  |   | 1.85 |  |   | 1.25 |  |
| Transportation, gathering and processing expenses per Boe | 1.15 |  |   | 0.84 |  |   | 0.96 |  |   | 0.86 |  |
| Total per Boe                                             | $ | 5.95 |  |   | $ | 4.76 |  |   | $ | 5.62 |  |   | $ | 4.84 |  |

----

|                                                                |
|----------------------------------------------------------------|
|                                                                |  |  |  |  |  |  |
|                                                           | Low | High |
|                                                           |   |   |
| Operating Expenses                                             |
| Lease operating expense ($/Boe)                                | $ | 2.65 |  | $ | 3.00 |  |
| Transportation, gathering and processing expenses ($/Boe)      | $ | 0.90 |  | $ | 1.10 |  |
| Production taxes (% of Crude Oil, Natural Gas & NGL sales) | 6 | % | 8 | % |
| General and administrative expense ($/Boe)                     | $ | 3.25 |  | $ | 3.60 |  |
| Depreciation, depletion and amortization ($/Boe)               | $ | 15.00 |  | $ | 16.50 |  |
| Estimated Price Realizations (% of NYMEX) (excludes TGP)       |
| Oil                                                            | 92% | 94% |
| Gas                                                            | 70% | 72% |
| NGLs                                                           | 32% | 36% |

----

|                                      |
|--------------------------------------|
|                                      |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| Adjusted Cash Flows from Operations  |
|                                 | Three Months Ended  September 30, |   | Nine Months Ended September 30, |
|                                 | 2017 |   | 2016 |   | 2017 |   | 2016 |
| Adjusted cash flows from operations: |   |   |   |   |   |   |   |
| Net cash from operating activities   | $ | 148.2 |  |   | $ | 163.0 |  |   | $ | 411.4 |  |   | $ | 360.8 |  |
| Changes in assets and liabilities    | 2.7 |  |   | (40.4 | ) |   | (3.9 | ) |   | (34.6 | ) |
| Adjusted cash flows from operations  | $ | 150.9 |  |   | $ | 122.6 |  |   | $ | 407.5 |  |   | $ | 326.2 |  |

----

|                                                     |
|-----------------------------------------------------|
|                                                     |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| Adjusted Net Income (Loss)                          |
|                                                | Three Months Ended  September 30, |   | Nine Months Ended September 30, |
|                                                | 2017 |   | 2016 |   | 2017 |   | 2016 |
| Adjusted net loss:                                  |   |   |   |   |   |   |   |
| Net loss                                            | $ | (292.5 | ) |   | $ | (23.3 | ) |   | $ | (205.1 | ) |   | $ | (190.3 | ) |
| (Gain) loss on commodity derivative instruments     | 52.2 |  |   | (19.4 | ) |   | (86.5 | ) |   | 62.3 |  |
| Net settlements on commodity derivative instruments | 9.6 |  |   | 47.7 |  |   | 22.2 |  |   | 167.9 |  |
| Tax effect of above adjustments                     | (23.2 | ) |   | (10.8 | ) |   | 24.0 |  |   | (87.6 | ) |
| Adjusted net loss                                   | $ | (253.9 | ) |   | $ | (5.8 | ) |   | $ | (245.4 | ) |   | $ | (47.7 | ) |
| Weighted-average diluted shares outstanding         | 65.9 |  |   | 48.8 |  |   | 65.8 |  |   | 45.7 |  |
| Adjusted diluted earnings per share                 | $ | (3.85 | ) |   | $ | (0.12 | ) |   | $ | (3.73 | ) |   | $ | (1.04 | ) |

|                                                     |
|-----------------------------------------------------|
|                                                     |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| Adjusted EBITDAX                                    |
|                                                | Three Months Ended  September 30, |   | Nine Months Ended September 30, |
|                                                | 2017 |   | 2016 |   | 2017 |   | 2016 |
| Net loss to adjusted EBITDAX:                       |   |   |   |   |   |   |   |
| Net loss                                            | $ | (292.5 | ) |   | $ | (23.3 | ) |   | $ | (205.1 | ) |   | $ | (190.3 | ) |
| (Gain) loss on commodity derivative instruments     | 52.2 |  |   | (19.4 | ) |   | (86.5 | ) |   | 62.3 |  |
| Net settlements on commodity derivative instruments | 9.6 |  |   | 47.7 |  |   | 22.2 |  |   | 167.9 |  |
| Non-cash stock-based compensation                   | 4.8 |  |   | 4.1 |  |   | 14.6 |  |   | 15.2 |  |
| Interest expense, net                               | 18.8 |  |   | 20.1 |  |   | 56.9 |  |   | 40.9 |  |
| Income tax benefit                                  | (122.4 | ) |   | (12.0 | ) |   | (71.5 | ) |   | (112.2 | ) |
| Impairment of properties and equipment              | 252.7 |  |   | 0.9 |  |   | 282.5 |  |   | 6.1 |  |
| Impairment of goodwill                              | 75.1 |  |   | — |  |   | 75.1 |  |   | — |  |
| Exploration, geologic, and geophysical expense      | 41.9 |  |   | 0.2 |  |   | 43.9 |  |   | 0.7 |  |
| Depreciation, depletion, and amortization           | 125.2 |  |   | 112.9 |  |   | 360.6 |  |   | 317.3 |  |
| Accretion of asset retirement obligations           | 1.5 |  |   | 1.8 |  |   | 4.9 |  |   | 5.4 |  |
| Adjusted EBITDAX                                    | $ | 166.9 |  |   | $ | 133.0 |  |   | $ | 497.6 |  |   | $ | 313.3 |  |
|                                                |   |   |   |   |   |   |   |
| Cash from operating activities to adjusted EBITDAX: |   |   |   |   |   |   |   |
| Net cash from operating activities                  | $ | 148.2 |  |   | $ | 163.0 |  |   | $ | 411.4 |  |   | $ | 360.8 |  |
| Interest expense, net                               | 18.8 |  |   | 20.1 |  |   | 56.9 |  |   | 40.9 |  |
| Amortization of debt discount and issuance costs    | (3.2 | ) |   | (9.9 | ) |   | (9.6 | ) |   | (13.0 | ) |
| Gain on sale of properties and equipment            | 0.1 |  |   | 0.2 |  |   | 0.8 |  |   | — |  |
| Exploration, geologic, and geophysical expense      | 41.9 |  |   | 0.2 |  |   | 43.9 |  |   | 0.7 |  |
| Exploratory dry hole costs                          | (41.2 | ) |   | — |  |   | (41.2 | ) |   | — |  |
| Other                                               | (0.4 | ) |   | (0.2 | ) |   | 39.3 |  |   | (41.5 | ) |
| Changes in assets and liabilities                   | 2.7 |  |   | (40.4 | ) |   | (3.9 | ) |   | (34.6 | ) |
| Adjusted EBITDAX                                    | $ | 166.9 |  |   | $ | 133.0 |  |   | $ | 497.6 |  |   | $ | 313.3 |  |

|     |                                                                                                                                                                          |
|-----|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| (1) |  Other includes the impact of provisions for the uncollectible notes receivable in the nine months ended September 30, 2017, and the six months ended June 30, 2016. |

----

|                                                                 |
|-----------------------------------------------------------------|
|                                                                 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|                                                            | Three Months Ended  September 30, |   | Nine Months Ended September 30, |
|                                                            | 2017 |   | 2016 |   | 2017 |   | 2016 |
|                                                            |   |   |   |   |   |   |   |
| Revenues                                                        |   |   |   |   |   |   |   |
| Crude oil, natural gas, and NGLs sales                          | $ | 232,733 |  |   | $ | 141,805 |  |   | $ | 636,027 |  |   | $ | 328,013 |  |
| Commodity price risk management gain (loss), net of settlements | (52,178 | ) |   | 19,397 |  |   | 86,458 |  |   | (62,348 | ) |
| Other income                                                    | 2,680 |  |   | 2,688 |  |   | 9,615 |  |   | 9,153 |  |
| Total revenues                                                  | 183,235 |  |   | 163,890 |  |   | 732,100 |  |   | 274,818 |  |
| Costs, expenses and other                                       |   |   |   |   |   |   |   |
| Lease operating expenses                                        | 25,353 |  |   | 14,001 |  |   | 65,170 |  |   | 43,006 |  |
| Production taxes                                                | 15,516 |  |   | 9,568 |  |   | 42,957 |  |   | 19,682 |  |
| Transportation, gathering and processing expenses               | 9,794 |  |   | 5,048 |  |   | 22,184 |  |   | 13,554 |  |
| General and administrative expense                              | 29,299 |  |   | 32,510 |  |   | 85,145 |  |   | 78,868 |  |
| Exploration, geologic, and geophysical expense                  | 41,908 |  |   | 241 |  |   | 43,895 |  |   | 688 |  |
| Depreciation, depletion and amortization                        | 125,238 |  |   | 112,927 |  |   | 360,567 |  |   | 317,329 |  |
| Impairment of properties and equipment                          | 252,740 |  |   | 933 |  |   | 282,499 |  |   | 6,104 |  |
| Impairment of goodwill                                          | 75,121 |  |   | — |  |   | 75,121 |  |   | — |  |
| Accretion of asset retirement obligations                       | 1,472 |  |   | 1,777 |  |   | 4,906 |  |   | 5,400 |  |
| Gain on sale of properties and equipment                        | (62 | ) |   | (219 | ) |   | (754 | ) |   | (43 | ) |
| Provision for uncollectible notes receivable                    | — |  |   | (700 | ) |   | (40,203 | ) |   | 44,038 |  |
| Other expenses                                                  | 2,947 |  |   | 3,092 |  |   | 10,365 |  |   | 7,795 |  |
| Total costs, expenses and other                                 | 579,326 |  |   | 179,178 |  |   | 951,852 |  |   | 536,421 |  |
| Loss from operations                                            | (396,091 | ) |   | (15,288 | ) |   | (219,752 | ) |   | (261,603 | ) |
| Interest expense                                                | (19,275 | ) |   | (20,193 | ) |   | (58,359 | ) |   | (42,759 | ) |
| Interest income                                                 | 479 |  |   | 140 |  |   | 1,487 |  |   | 1,875 |  |
| Loss before income taxes                                        | (414,887 | ) |   | (35,341 | ) |   | (276,624 | ) |   | (302,487 | ) |
| Income tax benefit                                              | 122,350 |  |   | 12,032 |  |   | 71,483 |  |   | 112,198 |  |
| Net loss                                                        | $ | (292,537 | ) |   | $ | (23,309 | ) |   | $ | (205,141 | ) |   | $ | (190,289 | ) |
|                                                            |   |   |   |   |   |   |   |
| Earnings per share:                                             |   |   |   |   |   |   |   |
| Basic                                                           | $ | (4.44 | ) |   | $ | (0.48 | ) |   | $ | (3.12 | ) |   | $ | (4.16 | ) |
| Diluted                                                         | $ | (4.44 | ) |   | $ | (0.48 | ) |   | $ | (3.12 | ) |   | $ | (4.16 | ) |
|                                                            |   |   |   |   |   |   |   |
| Weighted-average common shares outstanding:                     |   |   |   |   |   |   |   |
| Basic                                                           | 65,865 |  |   | 48,839 |  |   | 65,825 |  |   | 45,741 |  |
| Diluted                                                         | 65,865 |  |   | 48,839 |  |   | 65,825 |  |   | 45,741 |  |

----

|                                                                                                                                                                  |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|                                                                                                                                                                  |  |  |  |  |  |  |  |  |
|                                                                                                                                                             |   | September 30, 2017 |   | December 31, 2016 |
| Assets                                                                                                                                                           |   |   |   |   |
| Current assets:                                                                                                                                                  |   |   |   |   |
| Cash and cash equivalents                                                                                                                                        |   | $ | 136,429 |  |   | $ | 244,100 |  |
| Accounts receivable, net                                                                                                                                         |   | 167,276 |  |   | 143,392 |  |
| Fair value of derivatives                                                                                                                                        |   | 22,916 |  |   | 8,791 |  |
| Prepaid expenses and other current assets                                                                                                                        |   | 8,081 |  |   | 3,542 |  |
| Total current assets                                                                                                                                             |   | 334,702 |  |   | 399,825 |  |
| Properties and equipment, net                                                                                                                                    |   | 3,882,700 |  |   | 4,002,994 |  |
| Assets held-for-sale, net                                                                                                                                        |   | 41,484 |  |   | 5,272 |  |
| Fair value of derivatives                                                                                                                                        |   | 4,605 |  |   | 2,386 |  |
| Goodwill                                                                                                                                                         |   | — |  |   | 62,041 |  |
| Other assets                                                                                                                                                     |   | 43,796 |  |   | 13,324 |  |
| Total Assets                                                                                                                                                     |   | $ | 4,307,287 |  |   | $ | 4,485,842 |  |
|                                                                                                                                                             |   |   |   |   |
| Liabilities and Stockholders' Equity                                                                                                                             |   |   |   |   |
| Liabilities                                                                                                                                                      |   |   |   |   |
| Current liabilities:                                                                                                                                             |   |   |   |   |
| Accounts payable                                                                                                                                                 |   | $ | 164,080 |  |   | $ | 66,322 |  |
| Production tax liability                                                                                                                                         |   | 36,954 |  |   | 24,767 |  |
| Fair value of derivatives                                                                                                                                        |   | 25,987 |  |   | 53,595 |  |
| Funds held for distribution                                                                                                                                      |   | 94,387 |  |   | 71,339 |  |
| Accrued interest payable                                                                                                                                         |   | 18,929 |  |   | 15,930 |  |
| Other accrued expenses                                                                                                                                           |   | 33,451 |  |   | 38,625 |  |
| Total current liabilities                                                                                                                                        |   | 373,788 |  |   | 270,578 |  |
| Long-term debt                                                                                                                                                   |   | 1,051,571 |  |   | 1,043,954 |  |
| Deferred income taxes                                                                                                                                            |   | 326,472 |  |   | 400,867 |  |
| Asset retirement obligations                                                                                                                                     |   | 78,188 |  |   | 82,612 |  |
| Fair value of derivatives                                                                                                                                        |   | 7,261 |  |   | 27,595 |  |
| Other liabilities                                                                                                                                                |   | 43,405 |  |   | 37,482 |  |
| Total liabilities                                                                                                                                                |   | 1,880,685 |  |   | 1,863,088 |  |
|                                                                                                                                                             |   |   |   |   |
| Commitments and contingent liabilities                                                                                                                           |   |   |   |   |
|                                                                                                                                                             |   |   |   |   |
| Stockholders' equity                                                                                                                                             |   |   |   |   |
| Common shares - par value $0.01 per share, 150,000,000 authorized, 65,928,295 and 65,704,568 issued as of September 30, 2017 and December 31, 2016, respectively |   | 659 |  |   | 657 |  |
| Additional paid-in capital                                                                                                                                       |   | 2,500,532 |  |   | 2,489,557 |  |
| Retained earnings                                                                                                                                                |   | (70,933 | ) |   | 134,208 |  |
| Treasury shares - at cost, 62,772 and 28,763 as of September 30, 2017 and December 31, 2016, respectively                                                        |   | (3,656 | ) |   | (1,668 | ) |
| Total stockholders' equity                                                                                                                                       |   | 2,426,602 |  |   | 2,622,754 |  |
| Total Liabilities and Stockholders' Equity                                                                                                                       |   | $ | 4,307,287 |  |   | $ | 4,485,842 |  |
|                                                                                                                                                             |   |   |   |   |

----

|                                                                                                                           |
|---------------------------------------------------------------------------------------------------------------------------|
|                                                                                                                           |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|                                                                                                                      |   | Three Months Ended  September 30, |   | Nine Months Ended September 30, |
|                                                                                                                      |   | 2017 |   | 2016 |   | 2017 |   | 2016 |
| Cash flows from operating activities:                                                                                     |   |   |   |   |   |   |   |   |
| Net loss                                                                                                                  |   | $ | (292,537 | ) |   | $ | (23,309 | ) |   | $ | (205,141 | ) |   | $ | (190,289 | ) |
| Adjustments to net loss to reconcile to net cash from operating activities:                                               |   |   |   |   |   |   |   |   |
| Net change in fair value of unsettled commodity derivatives                                                               |   | 61,763 |  |   | 28,352 |  |   | (64,307 | ) |   | 230,177 |  |
| Depreciation, depletion and amortization                                                                                  |   | 125,238 |  |   | 112,927 |  |   | 360,567 |  |   | 317,329 |  |
| Impairment of properties and equipment                                                                                    |   | 252,740 |  |   | 933 |  |   | 282,499 |  |   | 6,104 |  |
| Impairment of goodwill                                                                                                    |   | 75,121 |  |   | — |  |   | 75,121 |  |   | — |  |
| Exploratory dry hole costs                                                                                                |   | 41,187 |  |   | — |  |   | 41,187 |  |   | — |  |
| Provision for uncollectible notes receivable                                                                              |   | — |  |   | (700 | ) |   | (40,203 | ) |   | 44,038 |  |
| Accretion of asset retirement obligations                                                                                 |   | 1,472 |  |   | 1,777 |  |   | 4,906 |  |   | 5,400 |  |
| Non-cash stock-based compensation                                                                                         |   | 4,761 |  |   | 4,079 |  |   | 14,587 |  |   | 15,205 |  |
| Gain on sale of properties and equipment                                                                                  |   | (62 | ) |   | (219 | ) |   | (754 | ) |   | (43 | ) |
| Amortization of debt discount and issuance costs                                                                          |   | 3,229 |  |   | 9,874 |  |   | 9,628 |  |   | 12,951 |  |
| Deferred income taxes                                                                                                     |   | (122,296 | ) |   | (11,817 | ) |   | (71,529 | ) |   | (114,136 | ) |
| Other                                                                                                                     |   | 316 |  |   | 761 |  |   | 986 |  |   | (526 | ) |
| Changes in assets and liabilities                                                                                         |   | (2,727 | ) |   | 40,375 |  |   | 3,855 |  |   | 34,621 |  |
| Net cash from operating activities                                                                                        |   | 148,205 |  |   | 163,033 |  |   | 411,402 |  |   | 360,831 |  |
| Cash flows from investing activities:                                                                                     |   |   |   |   |   |   |   |   |
| Capital expenditures for development of crude oil and natural gas properties                                              |   | (194,444 | ) |   | (117,536 | ) |   | (528,850 | ) |   | (352,213 | ) |
| Capital expenditures for other properties and equipment                                                                   |   | (1,441 | ) |   | (479 | ) |   | (3,740 | ) |   | (1,509 | ) |
| Acquisition of crude oil and natural gas properties, including settlement adjustments and deposit for pending acquisition |   | (19,854 | ) |   | (100,000 | ) |   | (14,482 | ) |   | (100,000 | ) |
| Proceeds from sale of properties and equipment                                                                            |   | 2,029 |  |   | 42 |  |   | 3,322 |  |   | 4,945 |  |
| Sale of promissory note                                                                                                   |   | — |  |   | — |  |   | 40,203 |  |   | — |  |
| Restricted cash                                                                                                           |   | — |  |   | — |  |   | (9,250 | ) |   | — |  |
| Sale of short-term investments                                                                                            |   | — |  |   | — |  |   | 49,890 |  |   | — |  |
| Purchases of short-term investments                                                                                       |   | — |  |   | — |  |   | (49,890 | ) |   | — |  |
| Net cash from investing activities                                                                                        |   | (213,710 | ) |   | (217,973 | ) |   | (512,797 | ) |   | (448,777 | ) |
| Cash flows from financing activities:                                                                                     |   |   |   |   |   |   |   |   |
| Proceeds from issuance of equity, net of issuance cost                                                                    |   | — |  |   | 558,497 |  |   | — |  |   | 855,072 |  |
| Proceeds from senior notes                                                                                                |   | — |  |   | 392,250 |  |   | — |  |   | 392,250 |  |
| Proceeds from convertible senior notes                                                                                    |   | — |  |   | 193,979 |  |   | — |  |   | 193,979 |  |
| Proceeds from revolving credit facility                                                                                   |   | — |  |   | — |  |   | — |  |   | 85,000 |  |
| Repayment of revolving credit facility                                                                                    |   | — |  |   | — |  |   | — |  |   | (122,000 | ) |
| Redemption of convertible notes                                                                                           |   | — |  |   | — |  |   | — |  |   | (115,000 | ) |
| Purchase of treasury shares                                                                                               |   | (51 | ) |   | (1,051 | ) |   | (5,325 | ) |   | (5,106 | ) |
| Other                                                                                                                     |   | (306 | ) |   | (142 | ) |   | (951 | ) |   | 593 |  |
| Net cash from financing activities                                                                                        |   | (357 | ) |   | 1,143,533 |  |   | (6,276 | ) |   | 1,284,788 |  |
| Net change in cash and cash equivalents                                                                                   |   | (65,862 | ) |   | 1,088,593 |  |   | (107,671 | ) |   | 1,196,842 |  |
| Cash and cash equivalents, beginning of period                                                                            |   | 202,291 |  |   | 109,099 |  |   | 244,100 |  |   | 850 |  |
| Cash and cash equivalents, end of period                                                                                  |   | $ | 136,429 |  |   | $ | 1,197,692 |  |   | $ | 136,429 |  |   | $ | 1,197,692 |  |

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|         |                                                                                                                                                     |
|---------|-----------------------------------------------------------------------------------------------------------------------------------------------------|
| • | changes in worldwide production volumes and demand, including economic conditions that might impact demand and prices for the products it produces; |

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

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|         |                                                                       |
|---------|-----------------------------------------------------------------------|
| • | reductions in the borrowing base under its 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 its crude oil, natural gas, and NGLs properties resulting in further impairments; |

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

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

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

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

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

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

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

|         |                                                                    |
|---------|--------------------------------------------------------------------|
| • | losses from its gas marketing business exceeding its expectations; |

|         |                                                                                                                                                                           |
|---------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| • | difficulties in integrating its operations as a result of any significant acquisitions, including its pending acquisitions and acreage exchanges in the Wattenberg Field; |

|         |                                                                                                                                                  |
|---------|--------------------------------------------------------------------------------------------------------------------------------------------------|
| • | increases or changes in operating costs, severance and ad valorem taxes, and increases or changes in drilling, completion, and facilities costs; |

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

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

|         |                                                                                                                                        |
|---------|----------------------------------------------------------------------------------------------------------------------------------------|
| • | increases or adverse changes in construction costs and procurement costs associated with future build out of midstream-related assets; |

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

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

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

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

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

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

|         |                                                                                  |
|---------|----------------------------------------------------------------------------------|
| • | cost of pending or future litigation, including recent environmental litigation; |

|         |                                                                         |
|---------|-------------------------------------------------------------------------|
| • | effect that acquisitions it may pursue has on its capital requirements; |

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

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

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