|
Oil and Gas Exploration and Production Industries Disclosures (Details) (USD $)
|
12 Months Ended |
|
|
Dec. 31, 2012
Boe
|
Dec. 31, 2011
Boe
|
Dec. 31, 2010
Boe
|
Dec. 31, 2009
Boe
|
| Proved Developed And Undeveloped Reserves (MBoe) [Rollforward] |
|
|
|
|
| Net proved reserves - beginning of period (MBoe) |
2,053,763 |
1,949,535 |
1,796,019 |
|
| Revisions of previous estimates (MBoe) |
(392,621) |
(59,163) |
(38,404) |
|
| Purchases in place (MBoe) |
4,098 |
521 |
14 |
|
| Extensions, discoveries and other additions (MBoe) |
406,932 |
387,255 |
395,984 |
|
| Sales in place (MBoe) |
(90,420) |
(68,247) |
(60,148) |
|
| Production (MBoe) |
(171,054) |
(156,138) |
(143,930) |
|
| Net proved reserves - end of period (MBoe) |
1,810,698 |
2,053,763 |
1,949,535 |
|
| Net Proved Developed and Undeveloped Reserves [Abstract] |
|
|
|
|
| Net Proved Developed Reserves (BOE) |
949,819 |
1,042,713 |
1,012,987 |
976,374 |
| Net Proved Undeveloped Reserve (BOE) |
860,879 |
1,011,050 |
936,548 |
819,646 |
| Revision of Proved Reserves Due to Decrease or Increase in the Average Natural Gas Price for the Year as Compared to Prior Year (stated in MMBoe) |
(531) |
(16) |
28 |
|
| Revisions of Proved Undeveloped Reserves (stated in MMBoe) |
(293) |
(7) |
(12) |
|
| Sales in Place of Proved Undeveloped Reserves (stated in MMBoe) |
19 |
9 |
8 |
|
| Proved Undeveloped Reserves Drilled and Transferred to Proved Developed Reserves (stated in MMBoe) |
138 |
144 |
118 |
|
| Capitalized Costs Related to Proved Undeveloped Reserves Drilled and Transferred to Proved Developed Reserves |
$ 2,764,000,000 |
$ 1,619,000,000 |
$ 1,280,000,000 |
|
| Capitalized Costs, Oil and Gas Producing Activities, Gross [Abstract] |
|
|
|
|
| Proved properties |
36,872,434,000 |
32,353,380,000 |
|
|
| Unproved properties |
1,253,864,000 |
1,311,055,000 |
|
|
| Total |
38,126,298,000 |
33,664,435,000 |
|
|
| Accumulated depreciation, depletion and amortization |
(16,849,068,000) |
(13,981,143,000) |
|
|
| Net capitalized costs |
$ 21,277,230,000 |
$ 19,683,292,000 |
|
|
|
Crude Oil (MBbl) [Member]
|
|
|
|
|
| Proved Developed and Undeveloped Reserves [Rollforward] |
|
|
|
|
| Net proved reserves - beginning of period |
517,493 |
385,922 |
219,539 |
|
| Revisions of previous estimates |
1,688 |
(25,756) |
(9,151) |
|
| Purchases in place |
1,010 |
9 |
13 |
|
| Extensions, discoveries and other additions |
255,686 |
203,001 |
204,476 |
|
| Sales in place |
(17,264) |
(4,301) |
(1,671) |
|
| Production |
(57,795) |
(41,382) |
(27,284) |
|
| Net proved reserves - end of period |
700,818 |
517,493 |
385,922 |
|
|
Natural Gas Liquids (MBbl) [Member]
|
|
|
|
|
| Proved Developed and Undeveloped Reserves [Rollforward] |
|
|
|
|
| Net proved reserves - beginning of period |
227,788 |
151,909 |
93,461 |
|
| Revisions of previous estimates |
47,856 |
36,042 |
27,294 |
|
| Purchases in place |
612 |
17 |
0 |
|
| Extensions, discoveries and other additions |
71,574 |
65,288 |
42,242 |
|
| Sales in place |
(7,377) |
(10,008) |
(8) |
|
| Production |
(20,490) |
(15,460) |
(11,080) |
|
| Net proved reserves - end of period |
319,963 |
227,788 |
151,909 |
|
|
Natural Gas (Bcf) [Member]
|
|
|
|
|
| Proved Developed and Undeveloped Reserves [Rollforward] |
|
|
|
|
| Net proved reserves - beginning of period |
7,850.9 |
8,470.2 |
8,898.1 |
|
| Revisions of previous estimates |
(2,653) |
(416.7) |
(339.3) |
|
| Purchases in place |
14.8 |
3.0 |
0 |
|
| Extensions, discoveries and other additions |
478.1 |
713.8 |
895.6 |
|
| Sales in place |
(394.7) |
(323.6) |
(350.8) |
|
| Production |
(556.6) |
(595.8) |
(633.4) |
|
| Net proved reserves - end of period |
4,739.5 |
7,850.9 |
8,470.2 |
|
| Net Proved Developed and Undeveloped Reserves [Abstract] |
|
|
|
|
| Net proved developed reserves |
2,979.5 |
4,155.6 |
4,457.8 |
4,633.2 |
| Net proved undeveloped reserves |
1,760.0 |
3,695.3 |
4,012.4 |
4,264.9 |
|
Liquids (MBbl) [Member]
|
|
|
|
|
| Net Proved Developed and Undeveloped Reserves [Abstract] |
|
|
|
|
| Net proved developed reserves |
453,242 |
350,118 |
270,017 |
204,177 |
| Net proved undeveloped reserves |
567,538 |
395,163 |
267,814 |
108,823 |
|
United States [Member]
|
|
|
|
|
| Proved Developed And Undeveloped Reserves (MBoe) [Rollforward] |
|
|
|
|
| Net proved reserves - beginning of period (MBoe) |
1,729,508 |
1,587,806 |
1,338,292 |
|
| Revisions of previous estimates (MBoe) |
(237,936) |
(42,526) |
(17,945) |
|
| Purchases in place (MBoe) |
4,098 |
521 |
14 |
|
| Extensions, discoveries and other additions (MBoe) |
392,196 |
373,602 |
378,582 |
|
| Sales in place (MBoe) |
(87,588) |
(68,247) |
(6,860) |
|
| Production (MBoe) |
(138,170) |
(121,648) |
(104,277) |
|
| Net proved reserves - end of period (MBoe) |
1,662,108 |
1,729,508 |
1,587,806 |
|
| Net Proved Developed and Undeveloped Reserves [Abstract] |
|
|
|
|
| Net Proved Developed Reserves (BOE) |
840,564 |
877,301 |
839,928 |
744,339 |
| Net Proved Undeveloped Reserve (BOE) |
821,544 |
852,207 |
747,878 |
593,953 |
|
United States [Member] | Crude Oil (MBbl) [Member]
|
|
|
|
|
| Proved Developed and Undeveloped Reserves [Rollforward] |
|
|
|
|
| Net proved reserves - beginning of period |
495,296 |
355,457 |
188,452 |
|
| Revisions of previous estimates |
4,105 |
(21,188) |
(8,313) |
|
| Purchases in place |
1,010 |
9 |
13 |
|
| Extensions, discoveries and other additions |
241,171 |
202,552 |
199,479 |
|
| Sales in place |
(15,921) |
(4,301) |
(1,082) |
|
| Production |
(54,632) |
(37,233) |
(23,092) |
|
| Net proved reserves - end of period |
671,029 |
495,296 |
355,457 |
|
|
United States [Member] | Natural Gas Liquids (MBbl) [Member]
|
|
|
|
|
| Proved Developed and Undeveloped Reserves [Rollforward] |
|
|
|
|
| Net proved reserves - beginning of period |
226,586 |
150,434 |
91,489 |
|
| Revisions of previous estimates |
47,293 |
35,999 |
27,490 |
|
| Purchases in place |
612 |
17 |
0 |
|
| Extensions, discoveries and other additions |
71,396 |
65,288 |
42,221 |
|
| Sales in place |
(7,300) |
(10,008) |
(2) |
|
| Production |
(20,181) |
(15,144) |
(10,764) |
|
| Net proved reserves - end of period |
318,406 |
226,586 |
150,434 |
|
|
United States [Member] | Natural Gas (Bcf) [Member]
|
|
|
|
|
| Proved Developed and Undeveloped Reserves [Rollforward] |
|
|
|
|
| Net proved reserves - beginning of period |
6,045.8 |
6,491.5 |
6,350.1 |
|
| Revisions of previous estimates |
(1,736) |
(344) |
(222.7) |
|
| Purchases in place |
14.8 |
3.0 |
0 |
|
| Extensions, discoveries and other additions |
477.8 |
634.6 |
821.3 |
|
| Sales in place |
(386.2) |
(323.6) |
(34.6) |
|
| Production |
(380.2) |
(415.7) |
(422.6) |
|
| Net proved reserves - end of period |
4,036.0 |
6,045.8 |
6,491.5 |
|
| Net Proved Developed and Undeveloped Reserves [Abstract] |
|
|
|
|
| Net proved developed reserves |
2,387.5 |
3,234.9 |
3,519.7 |
3,330.1 |
| Net proved undeveloped reserves |
1,648.5 |
2,810.8 |
2,971.7 |
3,020.0 |
|
United States [Member] | Liquids (MBbl) [Member]
|
|
|
|
|
| Net Proved Developed and Undeveloped Reserves [Abstract] |
|
|
|
|
| Net proved developed reserves |
442,648 |
338,144 |
253,308 |
189,322 |
| Net proved undeveloped reserves |
546,786 |
383,739 |
252,583 |
90,619 |
|
Canada [Member]
|
|
|
|
|
| Proved Developed And Undeveloped Reserves (MBoe) [Rollforward] |
|
|
|
|
| Net proved reserves - beginning of period (MBoe) |
192,448 |
216,084 |
285,808 |
|
| Revisions of previous estimates (MBoe) |
(151,015) |
(12,865) |
(5,288) |
|
| Purchases in place (MBoe) |
0 |
0 |
0 |
|
| Extensions, discoveries and other additions (MBoe) |
5,860 |
448 |
3,789 |
|
| Sales in place (MBoe) |
(2,832) |
0 |
(53,288) |
|
| Production (MBoe) |
(8,657) |
(11,219) |
(14,937) |
|
| Net proved reserves - end of period (MBoe) |
35,804 |
192,448 |
216,084 |
|
| Net Proved Developed and Undeveloped Reserves [Abstract] |
|
|
|
|
| Net Proved Developed Reserves (BOE) |
24,348 |
58,524 |
79,701 |
124,323 |
| Net Proved Undeveloped Reserve (BOE) |
11,456 |
133,924 |
136,383 |
161,486 |
|
Canada [Member] | Crude Oil (MBbl) [Member]
|
|
|
|
|
| Proved Developed and Undeveloped Reserves [Rollforward] |
|
|
|
|
| Net proved reserves - beginning of period |
18,592 |
25,636 |
25,586 |
|
| Revisions of previous estimates |
(2,493) |
(4,611) |
(104) |
|
| Purchases in place |
0 |
0 |
0 |
|
| Extensions, discoveries and other additions |
5,681 |
449 |
3,198 |
|
| Sales in place |
(1,343) |
0 |
(589) |
|
| Production |
(2,574) |
(2,882) |
(2,455) |
|
| Net proved reserves - end of period |
17,863 |
18,592 |
25,636 |
|
|
Canada [Member] | Natural Gas Liquids (MBbl) [Member]
|
|
|
|
|
| Proved Developed and Undeveloped Reserves [Rollforward] |
|
|
|
|
| Net proved reserves - beginning of period |
1,202 |
1,475 |
1,972 |
|
| Revisions of previous estimates |
563 |
43 |
(196) |
|
| Purchases in place |
0 |
0 |
0 |
|
| Extensions, discoveries and other additions |
178 |
0 |
21 |
|
| Sales in place |
(77) |
0 |
(6) |
|
| Production |
(309) |
(316) |
(316) |
|
| Net proved reserves - end of period |
1,557 |
1,202 |
1,475 |
|
|
Canada [Member] | Natural Gas (Bcf) [Member]
|
|
|
|
|
| Proved Developed and Undeveloped Reserves [Rollforward] |
|
|
|
|
| Net proved reserves - beginning of period |
1,035.9 |
1,133.8 |
1,549.5 |
|
| Revisions of previous estimates |
(894.5) |
(49.8) |
(29.9) |
|
| Purchases in place |
0 |
0 |
0 |
|
| Extensions, discoveries and other additions |
0 |
0 |
3.4 |
|
| Sales in place |
(8.5) |
0 |
(316.2) |
|
| Production |
(34.6) |
(48.1) |
(73) |
|
| Net proved reserves - end of period |
98.3 |
1,035.9 |
1,133.8 |
|
| Net Proved Developed and Undeveloped Reserves [Abstract] |
|
|
|
|
| Net proved developed reserves |
98.3 |
295.8 |
401.6 |
681.0 |
| Net proved undeveloped reserves |
0 |
740.1 |
732.2 |
868.5 |
|
Canada [Member] | Liquids (MBbl) [Member]
|
|
|
|
|
| Net Proved Developed and Undeveloped Reserves [Abstract] |
|
|
|
|
| Net proved developed reserves |
7,963 |
9,220 |
12,758 |
10,831 |
| Net proved undeveloped reserves |
11,456 |
10,574 |
14,352 |
16,727 |
|
Trinidad [Member]
|
|
|
|
|
| Proved Developed And Undeveloped Reserves (MBoe) [Rollforward] |
|
|
|
|
| Net proved reserves - beginning of period (MBoe) |
128,629 |
142,669 |
169,747 |
|
| Revisions of previous estimates (MBoe) |
(3,953) |
(4,011) |
(15,513) |
|
| Purchases in place (MBoe) |
0 |
0 |
0 |
|
| Extensions, discoveries and other additions (MBoe) |
0 |
12,455 |
12,250 |
|
| Sales in place (MBoe) |
0 |
0 |
0 |
|
| Production (MBoe) |
(23,616) |
(22,484) |
(23,815) |
|
| Net proved reserves - end of period (MBoe) |
101,060 |
128,629 |
142,669 |
|
| Net Proved Developed and Undeveloped Reserves [Abstract] |
|
|
|
|
| Net Proved Developed Reserves (BOE) |
81,826 |
103,710 |
90,382 |
105,540 |
| Net Proved Undeveloped Reserve (BOE) |
19,234 |
24,919 |
52,287 |
64,207 |
|
Trinidad [Member] | Crude Oil (MBbl) [Member]
|
|
|
|
|
| Proved Developed and Undeveloped Reserves [Rollforward] |
|
|
|
|
| Net proved reserves - beginning of period |
3,507 |
4,731 |
5,443 |
|
| Revisions of previous estimates |
71 |
18 |
(754) |
|
| Purchases in place |
0 |
0 |
0 |
|
| Extensions, discoveries and other additions |
0 |
0 |
1,751 |
|
| Sales in place |
0 |
0 |
0 |
|
| Production |
(550) |
(1,242) |
(1,709) |
|
| Net proved reserves - end of period |
3,028 |
3,507 |
4,731 |
|
|
Trinidad [Member] | Natural Gas Liquids (MBbl) [Member]
|
|
|
|
|
| Proved Developed and Undeveloped Reserves [Rollforward] |
|
|
|
|
| Net proved reserves - beginning of period |
0 |
0 |
0 |
|
| Revisions of previous estimates |
0 |
0 |
0 |
|
| Purchases in place |
0 |
0 |
0 |
|
| Extensions, discoveries and other additions |
0 |
0 |
0 |
|
| Sales in place |
0 |
0 |
0 |
|
| Production |
0 |
0 |
0 |
|
| Net proved reserves - end of period |
0 |
0 |
0 |
|
|
Trinidad [Member] | Natural Gas (Bcf) [Member]
|
|
|
|
|
| Proved Developed and Undeveloped Reserves [Rollforward] |
|
|
|
|
| Net proved reserves - beginning of period |
750.7 |
827.6 |
985.8 |
|
| Revisions of previous estimates |
(24.1) |
(24.2) |
(88.6) |
|
| Purchases in place |
0 |
0 |
0 |
|
| Extensions, discoveries and other additions |
0 |
74.7 |
63.0 |
|
| Sales in place |
0 |
0 |
0 |
|
| Production |
(138.4) |
(127.4) |
(132.6) |
|
| Net proved reserves - end of period |
588.2 |
750.7 |
827.6 |
|
| Net Proved Developed and Undeveloped Reserves [Abstract] |
|
|
|
|
| Net proved developed reserves |
476.7 |
606.3 |
519.2 |
609.4 |
| Net proved undeveloped reserves |
111.5 |
144.4 |
308.5 |
376.4 |
|
Trinidad [Member] | Liquids (MBbl) [Member]
|
|
|
|
|
| Net Proved Developed and Undeveloped Reserves [Abstract] |
|
|
|
|
| Net proved developed reserves |
2,378 |
2,657 |
3,853 |
3,966 |
| Net proved undeveloped reserves |
651 |
850 |
879 |
1,477 |
|
Other International [Member]
|
|
|
|
|
| Proved Developed And Undeveloped Reserves (MBoe) [Rollforward] |
|
|
|
|
| Net proved reserves - beginning of period (MBoe) |
3,178 |
2,976 |
2,172 |
|
| Revisions of previous estimates (MBoe) |
283 |
239 |
342 |
|
| Purchases in place (MBoe) |
0 |
0 |
0 |
|
| Extensions, discoveries and other additions (MBoe) |
8,876 |
750 |
1,363 |
|
| Sales in place (MBoe) |
0 |
0 |
0 |
|
| Production (MBoe) |
(611) |
(787) |
(901) |
|
| Net proved reserves - end of period (MBoe) |
11,726 |
3,178 |
2,976 |
|
| Net Proved Developed and Undeveloped Reserves [Abstract] |
|
|
|
|
| Net Proved Developed Reserves (BOE) |
3,081 |
3,178 |
2,976 |
2,172 |
| Net Proved Undeveloped Reserve (BOE) |
8,645 |
0 |
0 |
0 |
|
Other International [Member] | Crude Oil (MBbl) [Member]
|
|
|
|
|
| Proved Developed and Undeveloped Reserves [Rollforward] |
|
|
|
|
| Net proved reserves - beginning of period |
98 |
98 |
58 |
|
| Revisions of previous estimates |
5 |
25 |
20 |
|
| Purchases in place |
0 |
0 |
0 |
|
| Extensions, discoveries and other additions |
8,834 |
0 |
48 |
|
| Sales in place |
0 |
0 |
0 |
|
| Production |
(39) |
(25) |
(28) |
|
| Net proved reserves - end of period |
8,898 |
98 |
98 |
|
|
Other International [Member] | Natural Gas Liquids (MBbl) [Member]
|
|
|
|
|
| Proved Developed and Undeveloped Reserves [Rollforward] |
|
|
|
|
| Net proved reserves - beginning of period |
0 |
0 |
0 |
|
| Revisions of previous estimates |
0 |
0 |
0 |
|
| Purchases in place |
0 |
0 |
0 |
|
| Extensions, discoveries and other additions |
0 |
0 |
0 |
|
| Sales in place |
0 |
0 |
0 |
|
| Production |
0 |
0 |
0 |
|
| Net proved reserves - end of period |
0 |
0 |
0 |
|
|
Other International [Member] | Natural Gas (Bcf) [Member]
|
|
|
|
|
| Proved Developed and Undeveloped Reserves [Rollforward] |
|
|
|
|
| Net proved reserves - beginning of period |
18.5 |
17.3 |
12.7 |
|
| Revisions of previous estimates |
1.6 |
1.3 |
1.9 |
|
| Purchases in place |
0 |
0 |
0 |
|
| Extensions, discoveries and other additions |
0.3 |
4.5 |
7.9 |
|
| Sales in place |
0 |
0 |
0 |
|
| Production |
(3.4) |
(4.6) |
(5.2) |
|
| Net proved reserves - end of period |
17.0 |
18.5 |
17.3 |
|
| Net Proved Developed and Undeveloped Reserves [Abstract] |
|
|
|
|
| Net proved developed reserves |
17.0 |
18.6 |
17.3 |
12.7 |
| Net proved undeveloped reserves |
0 |
0 |
0 |
0 |
|
Other International [Member] | Liquids (MBbl) [Member]
|
|
|
|
|
| Net Proved Developed and Undeveloped Reserves [Abstract] |
|
|
|
|
| Net proved developed reserves |
253 |
97 |
98 |
58 |
| Net proved undeveloped reserves |
8,645 |
0 |
0 |
0 |