Amounts in US$'000 | | Oil &; gas properties | | | Furniture, equipment and vehicles | | Production facilities and machinery | | Buildings and improvements | | Construction in progress | | Exploration and evaluation assets(b) | | | Total | | |||||||
Cost at 1 January 2015 | | | 749,947 | | | | 12,057 | | | 111,646 | | | 9,527 | | | 59,425 | | | 140,444 | | | | 1,083,046 | |
Additions | | | (4,640) | (a) | | | 954 | | | - | | | 272 | | | 36,543 | | | 12,299 | | | | 45,428 | |
Currency translation differences | | | (27,522) | | | | (182) | | | (2,577) | | | (92) | | | - | | | (1,510) | | | | (31,883) | |
Disposals | | | (241) | | | | (13) | | | (1,685) | | | (84) | | | - | | | - | | | | (2,023) | |
Write-off / Impairment loss | | | (128,956) | | | | - | | | (13,242) | | | - | | | (7,376) | | | (30,084) | (c) | | | (179,658) | |
Transfers | | | 60,404 | | | | 929 | | | 30,690 | | | 895 | | | (58,769) | | | (34,149) | | | | - | |
Cost at 31 December 2015 | | | 648,992 | | | | 13,745 | | | 124,832 | | | 10,518 | | | 29,823 | | | 87,000 | | | | 914,910 | |
Additions | | | (3,531) | (a) | | | 406 | | | 466 | | | - | | | 20,322 | | | 18,181 | | | | 35,844 | |
Currency translation differences | | | 16,132 | | | | 126 | | | 2,077 | | | 35 | | | 73 | | | 790 | | | | 19,233 | |
Disposals | | | - | | | | (22) | | | - | | | - | | | - | | | - | | | | (22) | |
Write-off / Impairment reversal | | | 5,664 | | | | - | | | - | | | - | | | - | | | (31,366) | (d) | | | (25,702) | |
Transfers | | | 24,984 | | | | 102 | | | 5,038 | | | - | | | (17,292) | | | (12,832) | | | | - | |
Cost at 31 December 2016 | | | 692,241 | | | | 14,357 | | | 132,413 | | | 10,553 | | | 32,926 | | | 61,773 | | | | 944,263 | |
Additions | | | 7,997 | (a) | | | 954 | | | - | | | - | | | 66,953 | | | 49,455 | | | | 125,359 | |
Currency translation differences | | | (1,142) | | | | (12) | | | (147) | | | (3) | | | (62) | | | (104) | | | | (1,470) | |
Disposals | | | - | | | | (112) | | | - | | | (189) | | | - | | | - | | | | (301) | |
Write-off / Impairment reversal | | | - | | | | - | | | - | | | - | | | - | | | (5,834) | (e) | | | (5,834) | |
Transfers | | | 77,408 | | | | 211 | | | 25,130 | | | - | | | (61,827) | | | (40,922) | | | | - | |
Cost at 31 December 2017 | | | 776,504 | | | | 15,398 | | | 157,396 | | | 10,361 | | | 37,990 | | | 64,368 | | | | 1,062,017 | |
| | | | | | | | | | | | | | | | | | | | | | | | |
Depreciation and write-down at 1 January 2015 | | | (240,439) | | | | (4,449) | | | (45,147) | | | (2,244) | | | - | | | - | | | | (292,279) | |
Depreciation | | | (84,849) | | | | (2,850) | | | (15,467) | | | (874) | | | - | | | - | | | | (104,040) | |
Disposals | | | - | | | | 8 | | | - | | | 15 | | | - | | | - | | | | 23 | |
Currency translation differences | | | 4,115 | | | | (26) | | | - | | | (92) | | | - | | | - | | | | 3,997 | |
Depreciation and write-down at 31 December 2015 | | | (321,173) | | | | (7,317) | | | (60,614) | | | (3,195) | | | - | | | - | | | | (392,299) | |
Depreciation | | | (61,080) | | | | (2,702) | | | (10,788) | | | (920) | | | - | | | - | | | | (75,490) | |
Disposals | | | - | | | | 8 | | | - | | | - | | | - | | | - | | | | 8 | |
Currency translation differences | | | (2,486) | | | | (38) | | | (296) | | | (16) | | | - | | | - | | | | (2,836) | |
Depreciation and write-down at 31 December 2016 | | | (384,739) | | | | (10,049) | | | (71,698) | | | (4,131) | | | - | | | - | | | | (470,617) | |
Depreciation | | | (57,725) | | | | (1,948) | | | (14,558) | | | (844) | | | - | | | - | | | | (75,075) | |
Disposals | | | - | | | | 73 | | | - | | | 38 | | | - | | | - | | | | 111 | |
Currency translation differences | | | 930 | | | | 8 | | | 24 | | | 5 | | | - | | | - | | | | 967 | |
Depreciation and write-down at 31 December 2017 | | | (441,534) | | | | (11,916) | | | (86,232) | | | (4,932) | | | - | | | - | | | | (544,614) | |
| | | | | | | | | | | | | | | | | | | | | | | | |
Carrying amount at 31 December 2015 | | | 327,819 | | | | 6,428 | | | 64,218 | | | 7,323 | | | 29,823 | | | 87,000 | | | | 522,611 | |
Carrying amount at 31 December 2016 | | | 307,502 | | | | 4,308 | | | 60,715 | | | 6,422 | | | 32,926 | | | 61,773 | | | | 473,646 | |
Carrying amount at 31 December 2017 | | | 334,970 | | | | 3,482 | | | 71,164 | | | 5,429 | | | 37,990 | | | 64,368 | | | | 517,403 | |
Amounts in US$ '000 | | Total | | |
Exploration wells at 31 December 2015 | | | 22,906 | |
Additions | | | 15,088 | |
Write-offs | | | (19,949) | |
Transfers | | | (9,795) | |
Exploration wells at 31 December 2016 | | | 8,250 | |
Additions | | | 35,299 | |
Write-offs | | | (3,664) | |
Transfers | | | (29,281) | |
Exploration wells at 31 December 2017 | | | 10,604 | |