| Table C13. Oil and Natural Gas Reserve Balances by Region for FRS Companies, 2007 | |||||
| Reserves Statistics | Worldwide Total | United States | Total Foreign | ||
| Total | Onshore | Offshore | |||
| Crude Oil and Natural Gas Liquids | (million barrels) | ||||
| Beginning of Period | 29,882 | 13,916 | 10,603 | 3,314 | 15,966 |
| Revisions of Previous Estimates | 687 | 387 | 311 | 76 | 300 |
| Improved Recovery | 411 | 291 | 253 | 38 | 120 |
| Purchases of Minerals-in-Place | 160 | 147 | 103 | 45 | 13 |
| Extensions & Discoveries | 1,026 | 411 | 262 | 148 | 616 |
| Production | -2,740 | -1,040 | -709 | -331 | -1,699 |
| Sales of Minerals-in-Place | -1,004 | -374 | -265 | -108 | -630 |
| End of period | 28,423 | 13,739 | 10,557 | 3,181 | 14,684 |
| Proportionate Interest in Investee Reserves | -- | -- | -- | -- | 7,359 |
| Natural Gas Reserves | (billion cubic feet) | ||||
| Beginning of Period | 188,253 | 102,969 | 93,203 | 9,766 | 85,284 |
| Revisions of Previous Estimates | 6,183 | 5,160 | 5,109 | 51 | 1,023 |
| Improved Recovery | 931 | 756 | 714 | 41 | 175 |
| Purchases of Minerals-in-Place | 2,719 | 2,479 | 2,388 | 92 | 240 |
| Extensions & Discoveries | 12,089 | 9,508 | 9,115 | 393 | 2,581 |
| Production | -15,298 | -8,356 | -7,092 | -1,264 | -6,942 |
| Sales of Minerals-in-Place | -3,582 | -2,748 | -2,644 | -104 | -834 |
| End of Period | 191,295 | 109,768 | 100,792 | 8,976 | 81,527 |
| Proportionate Interest in Investee Reserves | -- | -- | -- | -- | 45,775 |
| See footnotes at end of table. | |||||