Upstream > Changes in reserves Key figures | Key operating ratios | Productions | Changes in reserves | Results of operations | Costs incurred | Capitalized cost | Standardized measure of discounted future net cash flow | Changes in the standardized measure of discounted future net cash flows | Main producing fields | Oil and gas acreage / Number of productive wells | Drilling activities | Liquified natural gas activity | Gas and Power activity | Upstream maps Changes in liquids reserves Download Excel table (in million of barrels) Consolidated Subsidiaries Equity affiliates & non consolidated Total group Europe Africa North America Far East Rest of the world Total Consolidated PROVED DEVELOPED AND UNDEVELOPED RESERVES Balance as of December 31, 1997 1,296 2,087 96 115 521 4,115 1,790 5,905 Revisions of previous estimates 134 130 3 23 84 374 (24) 350 Extensions, discoveries and other 67 237 3 -  191 498 83 581 Acquisitions of reserves in place 13 -  -  -  -  13 -  13 Sales of reserves in place (18) -  (16) -  -  (34) -  (34) Production for the year (157) (221) (6) (10) (56) (450) (98) (548) Balance as of December 31, 1998 1,335 2,233 80 128 740 4,516 1,751 6,267 Revisions of previous estimates 113 275 (31) (13) (87) 257 (24) 233 Extensions, discoveries and other 50 204 30 2 687 973 3 976 Acquisitions of reserves in place -  -  -  1 -  1 -  1 Sales of reserves in place -  -  (26) -  (45) (71) (2) (73) Production for the year (150) (210) (5) (10) (68) (443) (93) (535) Balance as of December 31, 1999 1,348 2,502 48 108 1,227 5,233 1,635 6,868 Revisions of previous estimates (20) 225 (1) 11 112 327 11 338 Extensions, discoveries and other 29 261 3 1 53 347 -  347 Acquisitions of reserves in place 3 0 -  -  -  3 -  3 Sales of reserves in place (40) (22) (7) -  (4) (73) -  (73) Production for the year (146) (205) (3) (9) (63) (426) (97) (523) Balance as of December 31, 2000 1,174 2,761 40 111 1,325 5,411 1,549 6,960 Minority interest in proved developed and undeveloped reserves December 31, 1997 -  81 -  -  -  81 -  81 December 31, 1998 26 60 -  -  -  86 -  86 December 31, 1999 36 60 -  -  -  96 -  96 December 31, 2000 35 56 -  -  -  91 -  91 Proved developed reserves December 31, 1997 802 1,068 35 85 406 2,396 1,775 4,171 December 31, 1998 845 1,052 22 93 538 2,550 1,661 4,211 December 31, 1999 975 1,176 14 74 423 2,662 1,570 4,232 December 31, 2000 824 1,156 9 69 416 2,474 1,023 3,497 All references to reserves are to the Company's share of such reserves, net of any liquids that may be taken by third parties as royalties in kind. Changes in gas reserves Download Excel table (in billion of cubic feet) Consolidated Subsidiaries Equity affiliates & non consolidated Total group Europe Africa North America Far East Rest of the world Total Consolidated PROVED DEVELOPED AND UNDEVELOPED RESERVES Balance as of December 31, 1997 7,302 2,360 705 6,139 921 17,427 1,590 19,017 Revisions of previous estimates 157 158 66 356 83 820 10 830 Extensions, discoveries and other 326 -  126 93 13 558 46 604 Acquisitions of reserves in place 58 -  1 -  24 83 -  83 Sales of reserves in place (59) -  (216) -  -  (275) -  -34 Production for the year (676) (14) (120) (253) (71) (1,134) (43) (1,177) Balance as of December 31, 1998 7,108 2,504 562 6,335 970 17,479 1,603 19,082 Revisions of previous estimates 520 (62) (85) 654 141 1,168 16 1,184 Extensions, discoveries and other 553 -  189 25 354 1,121 100 1,221 Acquisitions of reserves in place -  -  -  81 -  81 -  81 Sales of reserves in place (24) -  (28) -  (50) (102) -  (102) Production for the year (625) (51) (94) (312) (77) (1,159) (54) (1,213) Balance as of December 31, 1999 7,532 2,391 544 6,783 1,338 18,588 1,665 20,253 Revisions of previous estimates 510 (135) 26 8 176 585 2 587 Extensions, discoveries and other 97 236 98 109 734 1,274 75 1,349 Acquisitions of reserves in place 2 -  -  -  -  2 -  2 Sales of reserves in place (66) -  (45) -  -  (111) -  (111) Production for the year (654) (122) (88) (353) (91) (1,308) (67) (1,375) Balance as of December 31, 2000 7,421 2,370 535 6,547 2,157 19,030 1,675 20,705 Minority interest in proved developed and undeveloped reserves December 31, 1997 -  9 -  -  -  9 -  9 December 31, 1998 96 7 -  -  -  103 -  103 December 31, 1999 138 8 -  -  -  146 -  146 December 31, 2000 142 7 -  -  -  149 -  149 Proved developed reserves December 31, 1997 4,547 156 483 3,519 457 9,162 597 9,759 December 31, 1998 4,264 565 308 4,457 671 10,265 857 11,122 December 31, 1999 5,054 1,824 351 4,664 654 12,547 1,665 14,212 December 31, 2000 5,336 1,555 334 4,089 701 12,015 1,675 13,690 All references to reserves are to the Company's share of such reserves, net of any gas that may be taken by third parties as royalties in kind. Changes in liquids and gas reserves Download Excel table (in million of barrels of oil equivalent) Consolidated Subsidiaries Equity affiliates & non consolidated Total group Europe Africa North America Far East Rest of the world Total Consolidated PROVED DEVELOPED AND UNDEVELOPED RESERVES Balance as of December 31, 1997 2,574 2,500 214 1,169 695 7,152 2,091 9,243 Revisions of previous estimates 165 158 16 81 996 519 (23) 496 Extensions, discoveries and other 124 237 24 14 193 592 92 684 Acquisitions of reserves in place 23 -  -  -  5 28 -  28 Sales of reserves in place (28) -  (52) -  -  (80) -  (80) Production for the year (275) (223) (27) (55) (69) (649) (107) (756) Balance as of December 31, 1998 2,583 2,672 175 1,209 923 7,562 2,053 9,615 Revisions of previous estimates 220 265 (45) 119 (67) 492 (21) 471 Extensions, discoveries and other 149 204 62 6 753 1,174 22 1,196 Acquisitions of reserves in place -  -  -  14 -  14 -  14 Sales of reserves in place (4) -  (30) -  (54) (88) (2) (90) Production for the year (259) (220) (21) (66) (83) (649) (102) (751) Balance as of December 31, 1999 2,689 2,921 141 1,282 1,472 8,505 1,950 10,455 Revisions of previous estimates 156 233 6 23 147 565 12 577 Extensions, discoveries and other 45 308 21 19 189 582 14 596 Acquisitions of reserves in place 4 -  -  -  -  4 -  4 Sales of reserves in place (51) (23) (15) -  (4) (93) -  (93) Production for the year (267) (228) (20) (72) (80) (667) (110) (777) Balance as of December 31, 2000 2,576 3,211 133 1,252 1,724 8,896 1,866 10,762 Minority interest in proved developed and undeveloped reserves December 31, 1997 -  83 -  -  -  83 -  83 December 31, 1998 42 61 -  -  -  103 -  103 December 31, 1999 60 61 -  -  -  121 -  121 December 31, 2000 62 58 -  -  -  120 -  120 Proved developed reserves December 31, 1997 1,601 1,095 116 720 492 4,024 1,971 5,995 December 31, 1998 1,597 1,149 74 844 665 4,329 1,901 6,230 December 31, 1999 1,869 1,497 74 869 542 4,851 1,802 6,653 December 31, 2000 1,840 1,450 68 768 615 4,741 1,269 6,010 All references to reserves are to the Company's share of such reserves, net of any liquids or gas that may be taken by third parties as royalties in kind. Key figures | Key operating ratios | Productions | Changes in reserves | Results of operations | Costs incurred | Capitalized cost | Standardized measure of discounted future net cash flow | Changes in the standardized measure of discounted future net cash flows | Main producing fields | Oil and gas acreage / Number of productive wells | Drilling activities | Liquified natural gas activity | Gas and Power activity | Upstream maps